What is the main function of enzymes found in the smooth endoplasmic reticulum of eukaryotic cells?

a. breaking down macromolecules into smaller parts

b. generating ATP

c. building proteins

d. building lipids

Which of the following are found in prokaryotes? (choose all that apply)

a. a chromosome

b. nulei

c. mitochondria

d. plasma membrane

e. ribosomes

a. a chromosome

d. plasma membrane

e. ribosomes

What is electronegativity?

a. the ability of electrons to repel each other

b. the strength of "pull" a nucleus has on electrons in a covalent bond

c. the measure of negativity on an electron

In a covalent bond between carbon and oxygen... (choose all that apply)

a. the oxygen will have a net partial negative charge

b. electrons spend more time orbiting oxygen

c. electrons are "pulled" harder by oxygen

d. the bond is polar

all answers are true

a. the oxygen will have a net partial negative charge

b. electrons spend more time orbiting oxygen

c. electrons are "pulled" harder by oxygen

d. the bond is polar

Choose all correct statements about methane (CH₄)

a. methane is a non-polar molecule

b. methane is soluble in water becuase it has tetrahedral symmetry

c. The four bonds are all 90 degrees apart from each other

d. methan is soluble in water beause it forms hydrogen bonds with the oxygen in water

Which of the following functional groups have polar bonds? (choose all that apply)

a. phosphate groups

b. amino groups

c. hydoxyl groups

d. carboxyl groups

all answers are correct

a. phosphate groups

b. amino groups

c. hydoxyl groups

d. carboxyl groups

Which of the following functional groups tend to participate in reactions where they either lose or gain a proton? (choose 2)

a. hydroxyl groups

b. sulfhydryl groups

c. amino groups

d. carboxyl groups

c. amino groups

d. carboxyl groups

Which of the following are possible functions of carbohydrates?

a. provide an energy source

b. act as a catalyst

c. help as an identifier of cell type

d. act as a structural component of cells and organisms

a. provide an energy source

c. help as an identifier of cell type

d. act as a structural component of cells and organisms

Glucose and galactose are monosaccharides (sugars) with the same number of carbons.  What else is true about these two sugars? (Choose all correct answers)

a. they have the same function (can be used by the cell in the same way)

 b. they have the same molecular formula

c. they are both hydrophilic

d. they have the same molecular structure (spatial orientation)

 b. they have the same molecular formula

c. they are both hydrophilic

What functional group is important for forming glycosidic linkages between two monosaccharides? 

a. carboxyl

b. hydroxyl

c. phosphate

d. amine

Which of the following is TRUE? (Choose ALL correct answers)

a. Glycosidic linkages can form between different parts of a monosaccharide

a. Glycosidic linkages can form between different parts of a monosaccharide

       c. The hydroxyl group on carbon 1 is on the same "side" of the ring as the C6 carbon in beta-glucose

Which of the following is TRUE regarding polysaccharides? (Choose ALL correct answers)

a. starches and glycogen are both made up of glucose monomers

 b. starches and glycogen are both used for energy storage by animal cells

 c. starches and glycogen are both used for structural support by animal cells

 d. starches and glycogen contain alpha-1,4 and alpha-1,6 glycosidic linkages

a. starches and glycogen are both made up of glucose monomers

d. starches and glycogen contain alpha-1,4 and alpha-1,6 glycosidic linkages

Cellulose, the carbohydrate in plant cell walls, is not digestible by human enzymes.  What is true about cellulose? (Choose ALL correct answers)

a. cellulose is also made by animals and is used for energy storage

b. cellulose polymers hydrogen bond with one another

c. cellulose sheets are strong, making them useful structurally

d. it is made of chains of beta-glucoses

b. cellulose polymers hydrogen bond with one another

c. cellulose sheets are strong, making them useful structurally

d. it is made of chains of beta-glucoses

Which of the following are possible roles of proteins in cells? (Choose ALL correct answers)

a. singaling (communication between cells)

b. information storage

c. transport (helping move other molecules around)

d. catalysis

e. structural (helping keep shape of cell)

a. singaling (communication between cells)

c. transport (helping move other molecules around)

d. catalysis

e. structural (helping keep shape of cell)

Which of the following are found in ALL amino acids? (Check all that apply)

a. side chain

b. R-group

c. central alpha-carbon

d. arginine (R)

e. sulfate group

f. amino group

g. carboxyl group

h. polar bonds

a. side chain

b. R-group

c. central alpha-carbon

f. amino group

g. carboxyl group

h. polar bonds

A dipeptide is a short protein made up of two amino acids joined together...

a. by a single hydrogen bond

b. with a single glycosidic bond

c. covalently by a single peptide bond

d. covalently by two peptide bonds

N-terminus- amino group

C-terminus- carboxyl group

Which one of the following statements about protein composition is true? 

a. different proteins can contain the same amino acids, but in differ in sequence order and length

b. all proteins have the same molecular structure and overall shape, but are just made up of different amino acid sequences

c. proteins are 20 amino acids in length, but these amino acids are just arranged in different sequences

d. proteins can be made up of either monosaccharides or amino acids

Which of the following levels of structure contribute to the function of ALL proteins? (Check all that apply)

a. Quaternary structure- multiple polypeptides bind together to form a single functioning protein

b. primary structure- the sequence of amino acids

c. secondary structure- formation of internal structures (alpha-helices & beta-sheets)

d. tertiary structure- overall three-dimensional shape

b. primary structure- the sequence of amino acids

c. secondary structure- formation of internal structures (alpha-helices & beta-sheets)

d. tertiary structure- overall three-dimensional shape

True or False: An electron in an outer electron shell has more potential energy than an electron in an inner shell.

True

False

Potential energy stored in the bonds of a molecule is called...

a. entropy

b. chemical energy

c. temperature

d. kinetic energy

When a reaction releases heat, the reaction is...

a. isothermic

b. exothermic

c. catalyzed

d. endothermic

What is the best description of "entropy"?

a. the energy contained in a system

b. the strength of molecules in a system

c. the disorder of a system

d. the temperature of a system

In this reaction, how is entropy (S) of the system changing?

C₆H₁₂O₆ + 6O₂ -> 6CO₂ + 6H₂O + heat

a. it is increasing

b. it is staying the same

c. it is decreasing

In this reaction, how is enthalpy (H) of the molecules changing?

            C₆H₁₂O₆ + 6O₂  -> 6 CO₂ + 6 H₂O + heat

a. it is staying the same

b. it is increasing

c. it is decreasing

Changes in free energy are related to both enthalpy and entropy. Which equation best represents this?

a. deltaG = deltaS - TdeltaH

b. deltaS = deltaG + delta H

c. deltaG = delta H + TdeltaS

d. deltaG = deltaH - TdeltaS

Adenosine triphosphate (ATP) can be hydrolyzed to become ADP and inorganic phosphate.  It has a deltaG of -7.3 kcal/mol.  This reaction… (Choose ALL correct answers)

a. is spontaneous

b. is exergonic

c. is endothermic

d. releases energy

a. is spontaneous

b. is exergonic

d. releases energy

When a phosphate group from ATP is transferred onto a different molecule (the substrate) it is called…

a. catalysis

b. phosphorylation

c. spontaneous

If a reaction is spontaneous, then it will always occur very quickly.

True

False

We told you that the reaction Glu + NH3 [image]⟶ Gln + H2O (let's call it reaction 1) was an endergonic reaction.  However, Glu~P + NH3 [image]⟶ Gln + Pi (reaction 2) is exergonic. Which of the following are true?  (Choose ALL correct answers)

a. reaction 2 can occur in cells

b. reaction 1 can occur in cells

c. the reactants of reaction 2 have more total free energy (G) than the products of reaction 2

d. Glu~P has a higher chemical bond energy than Glu

e. Reaction 1 is spontaneous

a. reaction 2 can occur in cells

c. the reactants of reaction 2 have more total free energy (G) than the products of reaction 2

d. Glu~P has a higher chemical bond energy than Glu

We say that ATP hydrolysis (its breakdown) is "coupled" to drive endergonic reactions.  This means…  (Choose the ONE BEST answer)

a. a reactant must absorb heat released by ATP hydrloysis

b. ATP speeds up reactions

c. a part of ATP must form a chemical bond with another reactant molecule

d. endergonic reactions can occur in cells if ATP is nearby

We say that ATP hydrolysis (its breakdown) is "coupled" to drive endergonic reactions.  This means…  (Choose the ONE BEST answer)

a. R

b. the transition state intermediate

c. T+U

d. R+S

Which of the following is a source of the activation energy needed to reach the transition state intermediate? (choose the ONE best answer)

a. potential energy in bonds of reactants

b. kinetic energy of molecules that is converted to chemical bonds

c. chemical bond energy of ATP released when the bond breaks

Which of the following is true?

a. all enzymes are catalysts

b. all catalysts are proteins

c. all proteins are enzymes

d. all catalysts are enzymes

When a catalyst is provided for a reaction, which of the following is decreased?

a. the spontaneity of the reaction

b. Delta G (the Free Energy change in the reaction)

c. EA (the activation energy of the reaction)

Is ATP a catalyst?

No

Yes

The best definition of catalysis is

a. making a reaction more likely to proceed

b. making a reaction spontaneous

c. the input of energy into a reaction

d. the addition of ATP to a reaction

What two ways do catalysts help with reactions? (Choose TWO answers)

a. they make the reaction spontaneous

b. they reduce the deltaG of the reaction

c. they help reduce the activation energy

d. they help molecules interact in a precise orientation

c. they help reduce the activation energy

d. they help molecules interact in a precise orientation

Which of the following is the best definition of a "transition state" intermediate?

a. it is the only form of the reactants that fits into an active site

b. it is the lowest energy configuration of products of a reaction

c. it is an unstable (high energy) "mash up" of reactants

d. it is the catalyst of the reaction

Which of the following are TRUE regarding an active site of an enzyme?  (Choose ALL correct answers)

a. it contains R-groups

b. its structure can change after it binds to reactants

c. atoms within the active site interact with its specific substrate molecule(s)

d. the location of an active site in an enzyme is always near the N-terminus

a. it contains R-groups

b. its structure can change after it binds to reactants

c. atoms within the active site interact with its specific substrate molecule(s)

Which of the following are TRUE regarding enzymes? (Choose ALL that apply)

a. enzymes only work on organic molecules

b. the rate of enzyme-catalyzed reaction is dependent upon the amount of enzyme

c. the rate of enzyme-catalyzed reaction is dependent upon substrate concentration

d. molecules binding to a non-active site location can regulate an enzyme

e. enzymes are used up in the reaction

b. the rate of enzyme-catalyzed reaction is dependent upon the amount of enzyme

c. the rate of enzyme-catalyzed reaction is dependent upon substrate concentration

d. molecules binding to a non-active site location can regulate an enzyme

Imagine an enzyme in which the one of the substrates is glucose.  Which of the following interactions is most likely going to form between the enzyme's active site and the substrate?

a. hydrophobic interaction

b. ionic bond

c. disulfide bond

d. hydorgen bond

Which nucleic acid is capable of more diverse functions?

a. DNA

b. RNA

c. protein

Nucleotides consist of which of the following? Please check all that apply.

a. a 6-carbon sugar

b. an amino acid

c. a phosphate

d. a polar R-group

e. a 5-carbon sugar

f. a nitrogenous base

c. a phosphate

e. a 5-carbon sugar

f. a nitrogenous base

Nucleotides are linked by what type of bond during the formation of a single strand of nucleic acid?

a. hydrogen bond

b. hydrophobic interactions

c. glycosidic bond

d. peptide bond

e. phophodiester bond

f. ionic bond

When bases pair to form double-stranded DNA, which of the following pairings takes place? Please check all that apply.

a. pyrimidines pair with pyrimidines or purines

b. T with U

c. pyrimidines pair only with pyrimidines, and purines only with purines

d. pyrimidines pair with purines

e. A with T

f. A with U

g. G with A

h. C with G

d. pyrimidines pair with purines

e. A with T

h. C with G

Which of the following is FALSE about the polymerization of nucleotides?

a. nucleotides polymerize to form nucleic acids

b. nucleotides need to be activated prior to polymerization

c. the energy required for polymerization of nucleotides come from the breaking of phosphate bonds

d. nucleotides are always added onto the 3' end of the growing polymer

e. polymerization of nucleic acids in cells is spontaneous and does not require enzymes

Which of the following statements are TRUE about how RNA structure differs from DNA?  Please check all that are correct.

a. the sugar in DNA lacks an hydroxide that is present in the sugar found in RNA

b. DNA can form base pairs through hydrogen bonding, while RNA cannot form complementary base pairs

c. DNA can form a double helix but RNA cannot

d. RNA contains the bases A, C, G, and U, while DNA contains A, C, G, and T

e. RNA has a peptide-bonded backbone while DNA has a phosphodiesterase-bonded backbone

f. DNA does not form tertiary structures on its own, while RNA can fold into complex 3D shapes

a. the sugar in DNA lacks an hydroxide that is present in the sugar found in RNA

d. RNA contains the bases A, C, G, and U, while DNA contains A, C, G, and T

f. DNA does not form tertiary structures on its own, while RNA can fold into complex 3D shapes

What is the basic flow of information in the "Central Dogma"?

a. DNA to RNA to protein

b. RNA to DNA to protein

c. protein to RNA to DNA

d. DNA to protein to RNA

The "One gene, one enzyme" hypothesis is mostly true, but has been updated since it was first proposed.  Which is the better hypothesis?

a. one gene, one polypeptide

b. one gene, two enzymes

c. two genes, one enzyme

d. two genes, one polypeptide

What is the main function of RNA polymerase?

a. it catalyzes the reaction that polymerizes an RNA strand using a DNA template

b. it catalyzes the reaction that polymerizes an RNA strand using an RNA template

c. it catalyzes the reaction that polymerizes a DNA strand using a DNA template

d. it catalyzes the reaction that polymerizes a DNA strand using an RNA template

What is the process called when RNA polymerase does its job?

a. transcription

b. translation

c. mutation

d. RNA processing

What is the job of a ribosome?

a. it catalyzes the formation of a polypeptide using an mRNA template

b. it catalyzes the formation of an RNA strand using a protein template

c. it catalyzes the formation of an RNA strand using a DNA template

d. it catalyzes the formation of a polypeptide using a DNA template

What is the process called when ribosomes do their job?

a. translation

b. transcription

c. mutation

d. RNA processing

Which of the following are exceptions to the Central Dogma? (Choose ALL correct answers)

a. many RNAs are not translated, they have their own function as RNA

b. sometimes RNA is used as a template to make DNA (usually viral RNA)

c. some DNA is translated directly into protein ribosomes

d. some protein is used as a template to make RNA

a. many RNAs are not translated, they have their own function as RNA

b. sometimes RNA is used as a template

How many nucleotides (bases) make up a "codon", the unit of information that determines the amino acid in translation?

a. 3

b. 4

c. 2

d. 1

What is the role of sigma in bacteria?

a. it binds the promoter sequence of a gene

b. it adds nucleotides onto a growing RNA strand

c. it helps with termination of a new RNA strand

d. it moves along the DNA in the 5' to 3' direction

What is the "+1" site of a gene?

a. it is the nucleotide where the first ribonucleotide triphosphate base pairs with the DNA template strand

b. it is the nucleotide where sigma first binds to the DNA

c. it is the AUG sequence where translation begins

d. it is the -10 box

When RNA is synthesized… (Choose ALL correct answers)

a. ribonucleotide triphophates are a substrate for RNA polymerase

b. new phosphodiester bonds are made at the 3' end of the growing RNA strand

c. thymine bases in the DNA template pair with uracil bases in the RNA

d. the new RNA strand and the DNA template strand are parallel to each other (3' ends on the same side)

a. ribonucleotide triphophates are a substrate for RNA polymerase

b. new phosphodiester bonds are made at the 3' end of the growing RNA strand

What type of bond holds the growing RNA strand to the DNA template strand?

a. hydrogen bonds

b. hydrophobic interactions

c. covalent bonds

d. ionic bonds

Which of the following is true regarding the terminator signal sequence in bacteria? (Choose ALL correct answers)

a. it is a sequence found in the DNA

b. the terminator signal sequence in RNA forms a hairpin

c. RNA polymerase doesn't bind as well to the terminator signal in DNA

d. sigma binds to the terminator signal in RNA

a. it is a sequence found in the DNA

b. the terminator signal sequence in RNA forms a hairpin

Which of the following are TRUE? (Choose ALL correct answers)

a. the first nucleotide that hydrogen bonds to the template strand will be at the 5' end of the completed RNA molecule

b. adenosine triphosphate (ATP) is a substrate of RNA polymerase

c. all products of transcription are messenger RNA

d. RNA polymerase covalently bonds to the DNA during transcription

a. the first nucleotide that hydrogen bonds to the template strand will be at the 5' end of the completed RNA molecule

b. adenosine triphosphate (ATP) is a substrate of RNA polymerase

Which of the following is true regarding codons in translation? (Choose ALL correct answers)

a. one amino acid can be coded for by multiple different codons

b. the codon table has the codons that are found in mRNA

c. one codon can code for multiple different amino acids

d. the codon table has the anti-codons that are found in tRNA

a. one amino acid can be coded for by multiple different codons

b. the codon table has the codons that are found in mRNA

Which of the following is true regarding transfer RNAs (tRNAs)?  (Choose ALL correct answers)

a. tRNAs are made by RNA polymerase

b. a tRNA is one RNA molecule that pairs with itself to form three stem-loops

c. a tRNA has a 5' end and a 3' end

d. within the stem of a step-loop, the tRNA phosphodiester backbones are parallel to one another

a. tRNAs are made by RNA polymerase

b. a tRNA is one RNA molecule that pairs with itself to form three stem-loops

c. a tRNA has a 5' end and a 3' end

Which of the following is true regarding amino-acyl tRNA synthetases  (Choose ALL correct answers)

a. they are enzymes

b. they have a binding site for an anticodon

c. ATP is a substrate for amino-acyl tRNA synthetases

d. there are many different types of amino-acyl tRNA synthetases in a cell

a. they are enzymes

b. they have a binding site for an anticodon

c. ATP is a substrate for amino-acyl tRNA synthetases

d. there are many different types of amino-acyl tRNA synthetases in a cell

There are roughly 40 different tRNA molecules in cells.  Which of the following can help to explain why this is enough to successfully translate 61 different codons? (Choose ALL correct answers)

a. some amino acids are coded for by two or more codons

b. codons that code for the same amino acid tend to be the same in the first and second positions

c. nonstandard base pairs (like G-U) are allowed in the third position

d. some tRNA molecules can carry two amino acids at the same time

a. some amino acids are coded for by two or more codons

b. codons that code for the same amino acid tend to be the same in the first and second positions

c. nonstandard base pairs (like G-U) are allowed in the third position

Which of the following molecules should exit from the nucleus through nuclear pore complexes? (Choose ALL correct answers)

a. mRNA

b. tRNA

c. mitochondrial proteins

d. carbohydrates

a. mRNA

b. tRNA

Which of the following molecules should enter the nucleus through nuclear pore complexes? (Choose ALL correct answers)

a. NTPs

b. RNA polymerases

c. DNA polymerases

d. mRNA

a. NTPs

b. RNA polymerases

c. DNA polymerases

What shared characteristic do ALL lipids have?

a. they are mostly hydrophobic

b. they have the same structure

c. they are only found in membranes

d. they have phosphate head groups

e. they have a glycerol backbone

How is a phospholipid considered "amphipathic"?

a. it has a positively charged end and a negatively charged end

b. it has a hydrophobic end and a hydrophilic end

c. it has a polar end and an ionic end

d. it has a saturated end and an unsaturated end

Which of the following is TRUE regarding a phospholipid bilayer? Check all that apply.

a. fatt acid tails interact with each other and the phosphate head groups interact with water

b. phospholipids often "flip" from one layer to the other

c. phospholipids often move laterally within a single layer

d. phospholipid bilayers allow some substances to cross more easily than others

e. water can easily diffuse across a phospholipid bilayer

a. fatt acid tails interact with each other and the phosphate head groups interact with water

c. phospholipids often move laterally within a single layer

d. phospholipid bilayers allow some substances to cross more easily than others

e. water can easily diffuse across a phospholipid bilayer

Which one of the following is NOT true about cholesterol?

a. cholesterol is an important component of plasma membranes

b. cholesterol is amphipathic

c. steroid hormones are derived from cholesterol

d. adding cholesterol to membranes decreases membrane permeability

e. cholesterol has a fatty acid tail

Membranes are likely to be more permeable if: 

a. they contain higher levels of cholesterol

b. the phospholipid fatty acid chains are unsaturated

c. the phospholipid fatty acid chains are saturated

d. the temperature is reduced (colder)

The part of a membrane protein that is embedded within the interior of the lipid bilayer is most likely to be:

a. an alpha-helix containing hydrophobic amino acid side chains

b. an alpha-helix containing hydrophilic amino acid side chains

c. an alpha-helix with both hydrophobic and hydrophilic amino acid side chains

d. several beta-sheets

Which of the following is TRUE about diffusion? Please check all that apply.

a. diffusion is the movement of molecules and ions that result from their kinetic energy

b. solute molecules only move from an area of high concentration to an area of low concentration

c. diffusion requires energy

d. diffusion of water across a membrane is called osmosis

e. solutes diffuse across a membrane down its concentration gradient

f. diffusion is affected by temperature, steepness of gradient, and size of the molecules

g. water diffuses across a membrane from a hypertonic solution towards a hypotonic solution

a. diffusion is the movement of molecules and ions that result from their kinetic energy

d. diffusion of water across a membrane is called osmosis

e. solutes diffuse across a membrane down its concentration gradient

f. diffusion is affected by temperature, steepness of gradient, and size of the molecules

Which one of the following is FALSE about the sodium-potassium pump (Na+/K+-ATPase)? 

a. it requires energy from ATP to function

b. it is an example of active transport transport

c. two potassium ions is exchanged for every 3 sodium ions pumped across the membrane

d. sodium ions are moved against their electrochemical gradient

e. both sodium and potassium ions are moved into the cell

f. it is a transmembrane (or integral membrane) protein

What is the main purpose of "Cellular Respiration"?

a. production of ATP

b. production of glucose

c. production of O₂

Where does most of the glucose come from that most organisms use to make ATP?

a. only eukaryotes

b. fungus and animals

c. plants and other photosynthetic species

d. only prokaryotes

Why do glucose and molecular oxygen have more energy in their bonds than carbon dioxide and water?

a. there are more nonpolar bonds in glucose and oxygen

b. there are more nonpolar bonds in carbon dioxide and water

c. there are unpaired electrons in glucose and oxygen

d. glucose and oxygen are more plentiful

During cellular respiration, which of the following occurs? (Choose ALL correct answers)

a. the hydrogens in glucose are reduced

b. the oxygens in molecular oxygen are oxidized

c. the carbons in glucose are oxidized

d. the oxygens in molecular oxygen are reduced

c. the carbons in glucose are oxidized

d. the oxygens in molecular oxygen are reduced

Where is ATP synthase located in a eukaryotic cell?

a. in the lysosomal membrane

b. in the outer mitochondrial membrane

c. in the plasma membrane

d. in the inner mitochondrial membrane

Where does the energy (directly) come from that provides the force that ATP synthase needs to "squish" ADP and Pi together (to make ATP)?

a. from ATP hydrolysis

b. from the flow of hydrogen ions "down" a chemical gradient

c. from the breaking of phosphodiester bonds in RNA

d. from the heat within the mitochondria

Most of the components of the Electron Transport Chain (ETC) are what type of molecule?

a. protein

b. lipid

c. carbohydrate

d. nucleic acid

Ubiquinone (aka coenzyme Q, or "Q") is a component of the ETC, but it is a…

a. protein

b. carbohydrate

c. nucleic acid

d. lipid

In a eukaryotic cell, where does glycolysis take place?

a. in the mitochondrial matrix

b. in the plasma membrane of the cell

c. in the inner mitochondrial membrane

d. in the chloroplast

e. in the cytoplasm

In a eukaryotic cell, where does krebs cycle or the citric acid cycle take place?

a. in the mitochondrial matrix

b. in the plasma membrane of the cell

c. in the inner mitochondrial membrane

d. in the chloroplast

e. in the cytoplasm

In a eukaryotic cell, where does the electron transport chain take place?

a. in the mitochondrial matrix

b. in the plasma membrane of the cell

c. in the inner mitochondrial membrane

d. in the chloroplast

e. in the cytoplasm

In a eukaryotic cell, where does oxidative phosphorylation take place?

a. in the mitochondrial matrix

b. in the plasma membrane of the cell

c. in the inner mitochondrial membrane

d. in the chloroplast

e. in the cytoplasm

What is the initial substrate for glycolysis?

a. ATP

b. NaCl

c. glucose

d. galactose

What are the final products of aerobic respiration? 

a. ATP

b. CO₂

c. ADP

d. H₂O

e. pyruvate

f. O₂

a. ATP

b. CO₂

d. H₂O

Which process directly uses molecular oxygen (O₂)?

a. glycolysis

b. oxidative phosphorylation

c. krebs cycle

d. linking step

e. electron transport chain

During respiration, does glucose become more oxidized or more reduced?

a. oxidized

b. reduced

What is "substrate-level" phosphorylation?

a. the synthesis of ATP by transfer of a phosphate from an organic molecule to ADP

b. the synthesis of ATP by ATP synthase

c. the addition of an inorganic phosphate to ADP to make ATP

d. the addition of an inorganic phosphate to an organic molecule

During which part(s) of respiration is CO₂ a product? (Choose ALL correct answers)

a. citric acid cycle/krebs cycle

b. pyruvate processing/linking step

c. glycolysis

d. electron transport chain and oxidative phosphorylation

a. citric acid cycle/krebs cycle

b. pyruvate processing/linking step

During which part(s) of respiration are electron carriers (like NAD⁺ and FAD) reduced? (Choose ALL correct answers)

a. citric acid cycle/krebs cycle

b. pyruvate processing/linking step

c. glycolysis

d. electron transport chain and oxidative phosphorlyation

a. citric acid cycle/krebs cycle

b. pyruvate processing/linking step

c. glycolysis

During which part(s) of respiration is O₂ a substrate? (Choose ALL correct answers)

a. electron transport chain and oxidative phosphorylation

b. citric acid cycle/krebs cycle

c. pyruvate processing/linking step

d. glycolysis

The proton gradient across the inner mitochondrial membrane drives the ATP synthase enzyme to make ATP from ADP and Pi.  Where is that proton gradient in prokaryotes? 

a. across the plasma membrane

b. across the inner mitochondrial membrane

c. across the outer mitochondrial membrane

d. they don't need a proton gradient

Two NAD+ are reduced to NADH (per glucose) in the cytoplasm during glycolysis.  Can the electrons in NADH be used to make ATP while it is still in the cytoplasm?

yes

no

There is a specific protein found in the inner mitochondrial membrane called the ATP-ADP translocase.  It provides the path for ATP to leave the matrix and go into the cytoplasm and for ADP to enter the matrix from the cytoplasm. Which of the following is true regarding this process? (Choose ALL correct answers)

a. the translocase has a higher affinity for ATP when it is "open" toward the matrix

b. the translocase is required because ATP and ADP cannot pass through lipid bilayers

c. the translocase moves ATP across its concentration gradient

d. the translocase will also provide a path for pyruvate to enter the matrix

a. the translocase has a higher affinity for ATP when it is "open" toward the matrix

b. the translocase is required because ATP and ADP cannot pass through lipid bilayers

Why is the yield of ATP per glucose molecule (29 ATP) lower than theoretical calculations (38 ATP)?

a. energy is required for the transfer of some of the molecules from the cytoplasm to the matrix

b. energy is required to pump protons in the ETC

c. energy is required to transfer O₂ into cells

d. energy is required to keep glucose out of the matrix

Look at the detailed molecular structure of glucose.  How many non-polar bonds does glucose have? 

12

0

6

8

10

14

18

22

Look at the detailed molecular structures of carbon dioxide and water.  How many non-polar bonds do they have (if you consider them together?)

0

4

6

8

10

Which of the following molecules also have some non-polar bonds that might provide a source of energy for cells to make ATP? (Choose ALL correct answers)

a. carbohydrates other than glucose

b. lipids

c. nucleic acids

d. proteins

a. carbohydrates other than glucose

b. lipids

c. nucleic acids

d. proteins

Cellular respiration involves the oxidation of carbons.  According to redox rules, that means that…  (Choose ALL correct answers)

a. oxidations is the loss of electrons

b. if carbon is oxidized, something else must be reduced

c. oxidations is the gain of electrons

d. if carbon is oxidized, it changes the number of bonds it forms

a. oxidations is the loss of electrons

b. if carbon is oxidized, something else must be reduced

At certain steps in glycolysis and the Krebs cycle, an "electron carrier" is reduced at the same time carbon is oxidized.  Which of the following are examples of reduced electron carriers? (Choose ALL correct answers)

a. NADH

b. FADH₂

c. ADP

d. ATP

a. NADH

b. FADH₂

In eukaryotes, which of the following molecules are usually moved from the cytoplasm to the matrix of the mitochondria? (Choose ALL correct answers)

a. ADP + Pi

b. pyruvate

c. glucose

d. ATP

a. ADP + Pi

b. pyruvate

At every step (reaction) of glycolysis, what must be true?

a. There must be an enzyme that catalyzes that reaction

b. There must be ATP as a substrate for that reaction

c. There is oxidation of carbon

d. There is reduction of an electron carrier

Glycolysis has 10 reactions (5 of which occur twice per molecule of glucose).  How would you characterize the change in the structure of the glucose (or its derivative) in each step? (Fig. 9.5 – Glycolysis Pathway)

a. at every step there is a minor change in structure

b. at every step there is a phosphate group added to the molecule

c. at every step there is a major change in structure

d. at every step there is an addition of an oxygen

Considering the frequency of non-polar bonds in each type of molecule, which type of molecule should store the most energy (assuming you have the same mass of each)?

a. lipids

b. carbohydrates

c. proteins

If energy levels are high in a cell, which of the following can occur? (Choose ALL correct answers)

a. some of the intermediates of glycolysis can be used in pathways to make the sugars in ribonucleotides

b. acetyl CoA can be used in pathways that produce fatty acids

c. some of the intermediates of the Krebs cycle can be used in pathways that produce amino acids

d. pyruvate is likely to go through fermentation to produce lactic acid

a. some of the intermediates of glycolysis can be used in pathways to make the sugars in ribonucleotides

b. acetyl CoA can be used in pathways that produce fatty acids

c. some of the intermediates of the Krebs cycle can be used in pathways that produce amino acids

What happens when levels of ATP are high in a cell?

a. the enzyme for step 3 glycolysis is inhibited

b. the enzyme for step 3 of glycolysis speeds up and catalyzes more reactions

c. the enzyme for step 3 of glycolysis cannot bind to ATP at all

d. all enzymes in glycolysis are inhibited

Which of the following are considered evidence supporting "Endosymbiosis Theory" which suggests that mitochondria evolved from respiring prokaryotic organisms? (Choose ALL correct answers)

a. mitochondria have their own DNA which is circular

b. mitochondria have ribosomes which are different in structure than those in the cytoplasm

c. mitochondria divide through fission in a way that resembles bacterial division

d. mitochondria have proteins inside of them

a. mitochondria have their own DNA which is circular

b. mitochondria have ribosomes which are different in structure than those in the cytoplasm

c. mitochondria divide through fission in a way that resembles bacterial division

What is the main goal of the process called "fermentation"? 

a. it allows a cell to oxidize cytoplasmic NADH to NAD⁺so that glycolysis can proceed

b. it allows a cell to produce more CO₂ that can be used to make ATP

c. it generates more pyruvate that the cell can use to make ATP

Which is TRUE regarding anaerobic organisms? (Choose ALL correct answers)

a. they have evolved to utilize final electron acceptors other than O₂

b. they have ATP synthase and an electron transport chain

c. some can use molecules other than glucose as a source of "high energy" electrons

d. they can make as much ATP per molecule of glucose as aerobic organisms

a. they have evolved to utilize final electron acceptors other than O₂

b. they have ATP synthase and an electron transport chain

c. some can use molecules other than glucose as a source of "high energy" electrons

If a cell does not need a particular protein at a given time, which of the following strategies will be the "cheapest" (or most "efficient" in terms of energy and resources)?

a. do not transcribe the gene for this protein into mRNA

b. transcribe the gene for the protein into mRNA but then break it apart again quickly to prevent translation

c. transcribe and translate the gene into a protein, but then break the protein apart quickly

d. transcribe the gene for this protein into mRNA, then prevent translation by having a protein bind and block the ribosome binding site

Which of the following strategies will be the quickest way to change a protein's function?

a. modify the protein by attaching a functional group, such as a phosphate

b. digest the protein into amino acids at the proteasome

c. stop transcribing the protein's gene

d. stop transcribing the protein's mRNA

Which of the following is an example of translational control?

a. a regulatory protein binds the 5' end of an mRNA, preventing it from binding to a small ribosomal subunit

b. a regulatory protein binds the promoter region of a gene, preventing sigma from binding the promoter

c. a protein is activated by having its first 10 amino acids cut off

d. a mutation occurs in the promoter sequence of a gene

In order to regulate when and how often the transcription of a gene occurs, regulatory proteins should bind to…

a. regions of the DNA near the promoter

b. regions of the DNA near the terminator

c. regions of the mRNA near the 5' end

d. regions of the mRNA near the 3' end

Are there any genes that will be expressed all the time ("constitutively") by cells?

yes

no

Why do cells only express a subset of their genes (not ALL of their genes) at any given time? (Choose ALL correct answers)

a. it wastes a lot of energy to make RNA and proteins you don't need

b. it wastes a lot of resources (nucleotides and amino acids) to make RNA and proteins you don't need

c. cells in a multicellular organism can have different phenotypes by expressing different groups of genes

a. it wastes a lot of energy to make RNA and proteins you don't need

b. it wastes a lot of resources (nucleotides and amino acids) to make RNA and proteins you don't need

c. cells in a multicellular organism can have different phenotypes by expressing different groups of genes

Why are some genes constitutively expressed while the expression of others is regulated?

a. expression is based only on oxygen

b. differences in gene regulation lead to different amounts of expression

c. some genes have more copies in the genome

d. some gene products are needed at all times, and other gene products are only produced under some conditions to avoid waste and respond to stimuli

This sequence element is used as the binding site of sigma and RNA polymerase, which transcribes the DNA message into mRNA. All genes have one of these sites.

a. operator

b. promoter

Polymerase-blocking proteins, such as the LacI (repressor) protein, bind at these sites to physically block movement of the transcribing RNA polymerase.

a. operator

b. promoter

Why is transcriptional regulation is more common and/or efficient than translational regulation?

a. translational regulation would require mRNA to be made for every gene at all times, which is wasteful

b. translation occurs at ribosomes and can never be controlled

c. transcriptional regulation does not occur in prokaryotes

What does "constitutively" mean (as in a gene that is "constitutively expressed")?

a. all the time

b. at very high levels

c. under certain environmental conditions

d. where there is a lot of glucose

What is true about different bacterial promoters?

a. some promoters are "weaker" than others if they don't have the exact -35 and -10 that sigma binds best

b. all bacterial promoters bind sigma equally

c. some promoters can bind to RNA polymerase directly

d. some promoters are made of amino acids instead of nucleotides

Regulation of transcription could be done efficiently in which of the following ways? (Choose ALL correct answers)

a. blocking the initiation of transcription until the gene is needed

b. making initiation of transcription more likely when the gene is needed

c. blocking the termination of transcription until the gene is needed

d. making termination of transcription more likely when the gene is needed

a. blocking the initiation of transcription until the gene is needed

b. making initiation of transcription more likely when the gene is needed

Assume there is lactose in the cytoplasm of a bacterial cell.  Which of the following is the BEST time for that cell to break lactose down into glucose and galactose molecules?

a. when the cell is running out of ATP

b. when there is also lots of glucose in the cytoplasm

c. when there is also lots of ATP in the cytoplasm

d. when there is also lots of galactose in the cytoplasm

How does lactose get into a bacterial cell?

a. it passes through a lactose "channel"

b. it is permeable to the plasma membrane

c. it binds to a chaperone and passes through a nuclear pore

What else can bacteria (such as E. coli) use sugars for besides energy? (Choose ALL correct answers)

a. carbon source to build amino acids

b. carbon source to make vitamins

c. nitrogen source for making a nucleic acid's base

d. sulfur source for making cysteine (an amino acid)

a. carbon source to build amino acids

b. carbon source to make vitamins

To effectively regulate when genes get transcribed, "regulator proteins" need to…

a. bind to DNA

b. bind to mRNA

c. bind to ribosomes

d. bind to tRNA

What proteins in eukaryotes have a similar function to sigma?

a. basal transcription factors

b. regulatory transcription factors

c. RNA polymerases

d. transcription co-factors such as the "Mediator" complex

What is an "enhancer" element?

a. a sequence of DNA

b. a protein

c. a carbohydrate

d. a lipid

What do eukaryotic genes need before transcription can be initiated?

a. a large "transcriptional complex" assembled at the promoter of the gene

b. one basal transcription factor to bind the promoter of the gene

c. sigma to bind the promoter of the gene

d. RNA polymerase needs to find the start codon

Eukaryotic regulatory transcription factors such as "activators" can bind to which DNA elements? (Choose ALL correct answers)

a. enhancer elements

b. promoter proximal elements

c. the TATA box

d. the promoter

a. enhancer elements

b. promoter proximal elements

In which organisms do you think rates of transcription can be more "subtly" controlled?  In other words, which organisms have a broader range of variation in transcription rates?

a. eukaryotes

b. prokaryotes

By definition, "chromatin" consists of… (Choose ALL correct answers)

a. DNA

b. proteins (mostly histones)

c. lipids

d. carbohydrates

a. DNA

b. proteins (mostly histones)

Chromatin can be "decondensed" when "histone acetyltransferase" enzymes add which of the following to positively charged lysines? 

a. acetyl groups

b. ATP

c. phosphate groups

d. methyl groups

In which condition is transcription more likely to occur?

a. when chromatin is decondensed

b. when chromatin is condensed

What is a "coding region" of a gene or mRNA?

a. the part that codes for protein from the first 5'AUG3' to the stop codon

b. the 5' end of the gene

c. the 3' end of the gene

d. the parts of the gene that are transcribed but are not translated

Which parts of a processed eukaryotic mRNA are also found within the DNA that the mRNA was transcribed from? (Choose ALL correct answers)    

a. exons

b. 5' untranslated region (5' UTR)

c. the poly-A tail

d. the m7G cap

a. exons

b. 5' untranslated region (5' UTR)

 What does a "snRNP" consist of? (Choose ALL correct answers)

a. RNA

b. protein

c. polysaccharide

d. lipids

a. RNA

b. protein

What is formed when several snRNPs come together?

a. a spliceosome

b. a ribosome

c. a proteasome

d. a chromosome

What do the 5' Me-G Cap and the 3' poly-A tail do?

a. protect the mature mRNA from degradation by ribomucleases

b. make the mRNNA form a circle

c. tell the spliceosome were to splice the mRNA

d. help RNA polymerase transcibe faster

Which of the following best describes "alternative splicing"?

a. it occurs when different combinations of exons are kept in the processed mRNA
b. it occurs when different combinations of introns are kept in the processed mRNA
c. it occurs when different combinations of introns and exons are kept in the processed mRNA
d. it occurs when no introns are kept in the processed mRNA

If the mRNA from a gene is differentially spliced in different cell types….

a. the proteins in each cell type will be different

b. the proteins in each cell type will be the same

c. the primary mRNA in each cell type will be different

d. the mature (processed) mRNA in each cell type will be the same

What happens to nucleic acid strands that are spliced out of an mRNA?

a. they are degraded down into individual nucleotides

b. they are combined with other strands of RNA
c. they are translated into protein

d. they are transported out of the nucleus

Where is the "signal" found that a cell recognizes so that it knows to transport a new protein to the nucleus?

a. in the sequence of amino acids of part of the new protein

b. in the promoter region of the new protein's gene

c. near the 3' end of the mRNA of the new protein

d. near the ribosome binding site of the mRNA of the new protein

What is the name of the amino acid sequence that directs proteins to be made at the ER?

a. ER signal sequence

b. nuclear localization sequence

c. mitochondrial localization sequence

d. lysosomal signal sequence

What happens after a ribosome "docks" at the ER?

a. the protein it is synthesizing is translocated through a channel into the ER lumen

b. the protein it is synthesizing is moved to the nucleus

c. the protein it is synthesizing stays in the nucleus

d. the ribosome stops synthesizing any protein

How do proteins made in the ER get to the Golgi Apparatus?

a. they are moved in transport vesicles

b. they are translocated out through a channel in the ER membrane

c. they are attached to carbohydrates which drag them to the Golgi

d. they are never moved to the Golgi

In which of the following situations would DNA replication occur? Check ALL that apply.

a. When you need more cells to "patch" a scrape in your arm

b. When you step on a tack and you need to transmit that information to your brain

c. when your muscle cells are replacing the proteins needed for contraction

d. when a bacterial cell is going to divide into two cells

e. when a cell runs out of glucose and it needs to break down amino acids for energy instead

f. when a cell in a human embyro is going to divide into two cells

a. When you need more cells to "patch" a scrape in your arm

d. when a bacterial cell is going to divide into two cells

f. when a cell in a human embyro is going to divide into two cells

Which of the following are required "reagents" for DNA replication? (Choose ALL correct answers)

a. NTPs (nucleoside triphosphates- ATP, CTP, UTP, GTP)

b. dNTPs (deoxyribonucleoside triphosphates- dATP, dTTP, dGTP, dCTP)

c. DNA template molecules

d. RNA template molecules

a. NTPs (nucleoside triphosphates- ATP, CTP, UTP, GTP)

b. dNTPs (deoxyribonucleoside triphosphates- dATP, dTTP, dGTP, dCTP)

c. DNA template molecules

Which enzyme does the "most work" (the most DNA synthesis) during DNA replication?

a. helicase

b. primase

c. RNA polymerase

d. DNA polymerase 3

e. ligase

f. DNA polymerase 1

DNA synthesis occurs

a. in either the 5' to 3', or the 3' to 5' direction on any given DNA strand

b. only in the 3' to 5' direction

c. only in the 5' to 3' direction

d. in different directions: 5' to 3' on one strand, 3' to 5' on the other

Okazaki fragments are made during:  

a. DNA degradation

b. DNA replication, only on the lagging strand

c. DNA replication, only on the leading strand

d. DNA replication, on both leading and lagging strand

What parts of the genome (set of chromosomes) is replicated during eukaryotic DNA replication?

a. the whole genome

b. only the most useful parts of the genome (most frequently transcribed genes)

c. all of the chromosomes except the centromeres (the parts in the "middle" where sister chromatids are stuck together)

d. only the ends of the chromosomes (the telomeres)

Many organisms have evolved sex as a means of reproduction. Why?

a. sex helps an organism reproduce faster than any other method

b.sex speeds up the rate of natural selection on a mutation

c. sex allows a species to mutate more accurately

d. sex allows greater genetic variation in a population

Cats have a chromosome number 2N=38. How many chromosomes would you find in a maturing sperm in a feline testis, assuming that the sperm has entered Meiosis II? 

a. 38

b. 19

c. 32

d. 76

An egg is large and a sperm is small.  Why do you think this might be?

a. twins will result from eggs that have the same genetic material originally

b. eggs need to be able to move completely outside of the mother for fertilization

c. eggs are stationary and contain a supply of proteins, mRNAs, stored energy etc of the embryo-to-be

d. sperm are motile, sometimes traveling considerable distances (on a cellular scale)

c. eggs are stationary and contain a supply of proteins, mRNAs, stored energy etc of the embryo-to-be

d. sperm are motile, sometimes traveling considerable distances (on a cellular scale)

How many mature gametes are made in mammalian oogenesis? How many in mammalian spermatogenesis?

a. 4 mature sperm, 1 mature oocyte

b. 1 mature sperm, 4 mature oocyte

c. 4 primary spermatocytes, 4 primary oocytes

d. 4 mature gametes in both processes

How does the maturing oocyte move within the ovary?

a. it leaves the ovary and returns to the ovary once it is mature

b. clockwise

c. it doesn't (it gets bigger, but it doesn't move)

d. it migrates to different places in the ovary based on a complicated life cycle

The sperm or spermatocytes found in the epididymus are ________ mature compared to those in the seminiferous tubules.

a. more

b. equally

c. less

Which of the following is true regarding DNA polymerase III? (Choose ALL that are correct)

a. the enzyme can sense when a mismatched nucleotide has been added

b. the enzyme can cleave (cut) a recently made phosphodiester bond

c. the enzyme can add ribonucleotides as well as deoxyribonucleotides

d. the enzyme can add nucleotides onto the 5' end of a DNA strand

a. the enzyme can sense when a mismatched nucleotide has been added

b. the enzyme can cleave (cut) a recently made phosphodiester bond

Are all mistakes made by DNA polymerases fixed?

a. No, there will be an average 1 mismatch per billion nucleotides even after proofreading and mismatch repair

b. yes, the proofreading and mismatch repair enzymes can fix all of the mistakes

What is a "point mutation"?

a. a single base pair change

b. a transfer to several hundred base pairs to another position

c. a deletion a hundred base pairs

Which of the following types of mutation in a protein-coding gene will actually have no effect on protein sequence?

a. a silent mutation

b. a nonsense mutation

c. a missense mutation

d. a frameshift mutation

What does a "deleterious" mutation do?

a. lowers the fitness of the organism

b. increases the fitness of the organism

c. does not change the fitness of the organism

What is the enzyme telomerase able to do? (Choose ALL correct answers)

a. it can add deoxyribomucleotides to the 3' end of a DNA strand

b. it can use an RNA template for synthesis of a complementary strand

c. it can add deoxyribonucleotides to the 5' end of a DNA strand

d. it can use the existing DNA template to fill in the end of the chromosome

a. it can add deoxyribomucleotides to the 3' end of a DNA strand

b. it can use an RNA template for synthesis of a complementary strand

Which of the following is TRUE considering telomeres? (Choose ALL correct answers)

a. telomeres contain repeated sequences

b. telomeres are found on both ends of linear chromosomes

c. telomeres contain important protein-coding genes

d. telomeres are lengthened in all cells every time they divide in a multicellular organism

a. telomeres contain repeated sequences

b. telomeres are found on both ends of linear chromosomes

Why do we need topoisomerases?

a. to relieve "twisting" in the DNA helix caused by the separation of template strands

b. to copy the ends of chromosomes

c. to add short primers to template DNA strands

d. to synthesize the leading stand of DNA

The cell cycle has 4 phases, listed below.  Which phases together make up the stage called "Interphase"? (Choose ALL correct answers)

a. G1 phase

b. S phase

c. G2 phase

d. M phase

a. G1 phase

b. S phase

c. G2 phase

What happens during "S phase"?

a. DNA is replicated

b. chromosomes segregate

c. the cell divides through cytokinesis

d. the spindle fibers form

What happens during Gap (G1 and G2) phases?

a. cells grow and replicate organelles

b. DNA is replicated

c. the cell divides through cytokinesis

d. two daughter cells form

Which of the following is required for the cell to pass the "G1 checkpoint"? (Choose ALL correct answers)

a. cell sixe is big enough for cell to divide into two

b. there are enough resources of synthesis of DNA and organelle replication

c. the cell must have replicated its chromosomes

d. the cell must have proper spindle fibers

a. cell sixe is big enough for cell to divide into two

b. there are enough resources of synthesis of DNA and organelle replication

Which of the following are true? (Choose ALL correct answers)

a. we all have normal tumor suppressor genes

b. mutations in tumor suppressor genes can contribute to cancer

c. we all have mutations in our genome

d. mutations in any gene can contribute to cancer

a. we all have normal tumor suppressor genes

b. mutations in tumor suppressor genes can contribute to cancer

c. we all have mutations in our genome

What is the best definition of cancer?

a. uncontrolled cell division that interferes with normal cell/organ function

b. cells that ahve mutations

c. an inherited disease that affects cells of the breast and prostate

d. the presence of tumors

Which of the following are potential sources of mutation in DNA that could cause cancer? Hint: see chapter on DNA synthesis and repair (Choose ALL correct answers)

a. x-ray radiation

b. sunlight

c. certain chemicals

d. oxygen-related radicals like OH

a. x-ray radiation

b. sunlight

c. certain chemicals

d. oxygen-related radicals like OH

In which cells will DNA replication occur? (Choose ALL correct answers)

a. spermatogonia

b. differentiated sperm

c. follicle cells during follicle growth

d. 2' oocyte

e. 1' spermatocyte

a. spermatogonia

c. follicle cells during follicle growth

e. 1' spermatocyte

The sequence of events that takes place at meiosis is:

a. a round of cell division, DNA replication, then another round of cell division

b. two rounds of cell division without prior DNA replication

c. DNA replication followed by one round of cell division

d. DNA replication follwed by two round of cell division

In preparation for meiosis I:

a. sister chromatids separate and align on the metaphase plate

b. homologous pairs of chromosomes align on the metaphase plate

c. autosomes, but not sex chromosomes, align on the metaphase plate

d. each chromoseom lines up by itself on the metaphase plate

The gene for human beta-globin is found on chromosome 11. How many copies of the beta-globin gene are present in a cell that has replicated its DNA, but not yet begun meiosis I ?

a. 1

b. 2

c. 4

d. 8

e. 11

If the diploid chromosome number of an organism is 2N=12, how many chromosomes will be found in this organism's sperm?

a. 12 replicated chromosomes

b. 12 unreplicated chromosomes

c. 6 replicated chromosomes

d. 6 unreplicated chromosomes

e. 3 replicated chromosomes

f. 3 unreplicated chromosomes

If the diploid chromosome number of an organism is 2N=12, how many chromosomes will be found in this organism's 1° oocytes?

a. 12 replicated chromosomes

b. 12 unreplicated chromosomes

c. 6 replicated chromosomes

d. 6 unreplicated chromosomes

e. 3 replicated chromosomes

f. 3 unreplicated chromosomes

Mammalian oocytes are ovulated right after the oocyte completes Meiosis I. How do you describe the chromosomes in the cell right after ovulation?

a. haploid, replicated chromosomes

b. haploid, unreplicated chromosomes

c. diploid, replicated chromosomes

d. diploid, unreplicated chromosomes

Which of the following compounds is a purely protein component of the extracellular matrix of animals or of the cell walls of plants?

a. collagen

b. cellulose

c. pectin

d. proteoglycan

Why are extracellular matrices and cell walls important?  (Choose ALL correct answers)

a. they form a protective structure around cells

b. they help define the cell's shape

c. they help cells attach to each other in a multicellular organism

d. they play a large role in cellular respiration

a. they form a protective structure around cells

b. they help define the cell's shape

c. they help cells attach to each other in a multicellular organism

Where can you find the receptors for lipid-soluble signaling molecules (steroid hormones, typically)?

a. in the cytoplasm

b. in the plasma membrane

c. in the extracellular space

Most steroid hormones bind to receptors that act directly as…

a. transcription factors

b. protein kinases

c. membrane proteins

d. enzymes that synthesize cAMP

When a hydrophilic signaling molecule binds to the extracellular portion of a membrane receptor on a new cell, how does the "inside" of the cell know that the interaction occurred?  (Choose the ONE best answer)

a. when the receptor binds to the molecule, it changes shape, altering its function in some way

b. when the receptor binds to the molecule, it "flips" in the membrane so that the extracellular portion is now on the inside

c. when the receptor binds to the molecule, its function changes without a change in shape

d. when the receptor binds to the molecule, the inside just "knows" without any change in the receptor

Which of the following intracellular events could be part of a response to a hydrophillic signal molecule binding its receptor? (Choose ALL correct answers)

a. a change in gene expression by activation of a transcription factor

b. an increase in an enzyme's activity (such as kinase)

c. the opening of an ion channel in the membrane

d. an increase in the concentration of a "second messenger"

a. a change in gene expression by activation of a transcription factor

b. an increase in an enzyme's activity (such as kinase)

c. the opening of an ion channel in the membrane

d. an increase in the concentration of a "second messenger"

Which of the following are found in sperm cells? (Choose ALL correct answers)

a. acrosome

b. chromosomes

c. jelly layer

d. vitelline envelope

a. acrosome

b. chromosomes

Which of the following are found on the outside of sea urchin oocytes? (Choose ALL correct answers)

a. jelly layer

b. vitelline envelope

c. chromosomes

d. cortical granules

a. jelly layer

b. vitelline envelope

How does a sperm know where to find an oocyte?

a. the oocyte releases a signal molecule that the sperm has a receptor for

b. the oocyte releases receptors that the sperm can bind to

c. the sperm releases a signal molecule that the oocyte has a receptor for

d. the sperm randomly swims and just hopes to hump into a oocyte

What important molecules can be found inside an acrosome? (Choose ALL correct answers)

a. enzymes to digest jelly layer proteins

b. bindin

c. chromosomes

d. mitochondria

a. enzymes to digest jelly layer proteins

b. bindin

What important molecules can be found inside sea urchin oocyte cortical granules? (Choose ALL correct answers)

a. enzymes to digest the receptors that bind sperm

b. cross-linking molecules that harden the fertilizatoin envelope

c. ions and other molecules that attract water to "swell" the fertilization envelope

d. chromosomes

a. enzymes to digest the receptors that bind sperm

b. cross-linking molecules that harden the fertilizatoin envelope

c. ions and other molecules that attract water to "swell" the fertilization envelope

What is the main purpose of the cortical granules releasing their contents?

a. they help prevent more than one sperm from entering an egg (polyspermy)

b. they help make sure the sperm can find the egg

c. they help digest extra chromosomes

d. they help prevent the wrong speciesof sperm from binding

Which of the following is a "essential developmental processes"? (Choose ALL correct answers) Which of the following is a "essential developmental processes"? (Choose ALL correct answers)

a. cell differentiation

b. cell proliferation

c. cell signaling

d. cell movement

a. cell differentiation

b. cell proliferation

c. cell signaling

d. cell movement

When cells differentiate, they…

a. express different genes

b. cut out parts of the genome they don't need

c. divide quickly into many smaller cells

"Cleavage" is the first stage of embryonic development.  What is the main goal of this stage? (Choose the ONE best answer)

a. to make a lot of cells

b. to make the embryo much larger in volume

c. to differentiate cells into muscle and neurons

d. to make gametes in the new embryo

Which TWO stages of the cell cycle must be almost completely skipped during the Cleavage stage, based on the fact the cells get smaller and smaller? (Choose TWO answers)

a. G1

b. G2

c. S

d. M

a. G1

b. G2

Which of the following are molecules that follicle cells should have transferred to the developing oocyte in order to support the Cleavage stage in early development? (Choose ALL correct answers)

a. dNTPs and rNTPs

b. glucose

c. extra amino acids and lipids

d. extra chromosomes

a. dNTPs and rNTPs

b. glucose

c. extra amino acids and lipids

Where is ALL the information needed to make an entire organism located? Check all that apply

a. in only certain cell layers of the developing embryo

b. in the sperm

c. in all somatic cells

d. in the egg cell (ova)

e. in the zygote

c. in all somatic cells

e. in the zygote

What are the three embryonic "germ layers" of vertebrates? Check all that apply.

a. mesoderm

b. ultraderm

c. endoderm

d. yolk

e. ectoderm

a. mesoderm

c. endoderm

e. ectoderm

Which of the following adult cells are formed from mesoderm?  Please check all that apply.

a. muscle cells

b. neural cells

c. blood cells

d. bone cells

e. lining of the intestinal tract

a. muscle cells

c. blood cells

d. bone cells

Which of the following adult cells are formed from ectoderm? Check all that apply.

a. neural cells (neurons)

b. skin cells

c. lining of the intestinal tract

d. bone cells

e. blood cells

a. neural cells (neurons)

b. skin cells

Which part of your body is a tube that is contiguous with the external world?

a. your circulatory system

b. your digestive tract

c. your neural tube (spinal cord and brain)

d. your limbs (arms and legs)

True or False: The blastocoel is an embryonic cavity that later becomes the future gut (digestive system).

True

False

Which of the following are examples of differentiated cells? (Choose all that apply)

a. a cell in the early embryo undergoing cleavage

b. a muscle cell that can contract

c. a photoreceptor cell in your eye that can detect light (and send signals to the brain)

d. a neuron that has axons (to send signals) and dendrites (to receive signals)

e. a spermatid that has not yet developed a flagellum

f. a red blood cell that makes hemoglobin

b. a muscle cell that can contract

c. a photoreceptor cell in your eye that can detect light (and send signals to the brain)

d. a neuron that has axons (to send signals) and dendrites (to receive signals)

f. a red blood cell that makes hemoglobin

What is a somite?

a. a block of ectodermal cells underneath the neural tube

b. a block of mesodermal cells next to the neural tube

c. a block of mesodermal cells underneath the neural tube

d. a block of ectodermal cells next to the neural tube

When do somites form?

a. before the neural tube forms

b. before gastrulation

c. before cleavage

d. after the neural tube forms

What is the fate of the somites?

a. they become the lining of the lungs and the gut in each segment of the body

b. they become the central nervous system (spinal cord and brain)

c. they become the epidermis of the skin in each segement of the body

d. they become the muscles, bones, and dermal layers in each segment of the body

What is the neural tube?

a. a tube formed from the mesoderm that becomes the central nervous system (spinal cord and brain)

b. a tube formed from ectoderm that becomes the central nervous system (spinal cord and brain)

c. a tube formed from mesoderm that becomes the spinal column bones

d. a tube formed from ectoderm that becomes the spinal cloumn bones

What is the notochord?

a. a rod of mesodermal cells that becomes the neural tube

b. a roed of ectodermal cells that becomes the neural tube

c. a rod of mesodermal cells that singals the formation of the neural tube

d. a rod of ectodermal cells that singals the formation of the neural tube

Which of the following are features of cell determination in the embryo? (Choose ALL correct answers)

a. it is a gradual change in patterns of chromatin condensation and gene expression

b. certain genes are cut out of the genome as cell determination progresses

c. transcription factors play a large role in cell determination

d. it is a function of the cell's location in the embyro (induced by signals from neighbors)

a. it is a gradual change in patterns of chromatin condensation and gene expression

c. transcription factors play a large role in cell determination

d. it is a function of the cell's location in the embyro (induced by signals from neighbors)

Do growing chicks get any nutrients from the mother (directly or indirectly) after the egg is laid?

a. No, the developing chick finds all of it's own nutrients

b. yes, mother hens give constant direct nutrient supply

c. yes, the mother indirectly gives nutrition by depositing it in the yolk before laying the egg

This early process intiates multicellularity

a. neurulation

b. gastrulation

c. body folding

d. cleavage

This process produces three embryonic cell layers

a. body folding

b. cleavage

c. gastrulation

d. neurulation

This specifically-located process produces the neural tube

a. gastrulation

b. neurulation

c. cleavage

d. body folding

This complicated series of cell movements produces the overall body plan

a. gastrulation

b. body folding

c. cleavage

d. neurulation

In figure 23.11 (which represents an embryo in early somite development), what was the original fate of the two removed parts of the somites in the top panel? (Hint: you will need to reference figure 23.10)

a. bone and dermal layer cells

b. bone and muscle cells

c. muscle and dermal layer cells

d. only muscle cells

In the middle panel of figure 23.11, the removed parts are placed in a new location.  What is the normal cell fate of somite cells in that location?

a. muscles in limbs

b. dermal layer cells

c. bone cells

d. muscles in the back

a. muscles in limbs

The bottom panel of figure 23.11, shows the fate of the transplanted tissues.  Were the cells determined (narrowed to one cell fate) before they were transplanted? 

No

Yes

If you took an embryo at a later stage (older somites), this same experiment would give very different results.  The transplanted regions would maintain the fate from their original locations.  Based on location, where could the signal come from that triggers the top quadrant's cell fate (the cells that become the dermal layer of the skin)? 

a. the non-neural ectoderm

b. the neural tube

c. the mesoderm

d. the endoderm

What does figure 23.12 show about cell fate determination (commitment)?

a. the expression of a single gene can alter cell fate

b. that signals secreted by myoblasts can alter cell fate

Based on the data in figure 22.1, think about the evolution of water birds versus land birds (ducks vs. chickens, for example).  Which is the most likely?

a. ducks evolved to have less apoptosis than chickens during foot development

b. ducks evolved to have more apoptosis than chickens during foot development

c. ducks evolved to have more cell proliferation than chickens during foot development

d. ducks evolved to have less cell proliferation than chickens during foot development

In the image below, why do we see more Gremlin (Gre) expression (red in diagram) in duck and bat limbs than in mouse?

 [image]

a. gremlin inhibits apoptosis, so ducks get webbed feet and bats get wings

b. gremlin activates apoptosis, so mice get individual fingers

c. BMPs inhibit apoptosis, so ducks get webbed feet and bats get wings

d. BMPs activate apoptosis, so ducks get webbed feet and bats get wings

Which of the following is true about PCR?  (Check all that apply)

a. PCR can be used for amplifying a specific region of DNA

b. PCR can be used to make proteins from DNA

c. PCR requires heating and cooling of the reaction solution

d. PCR only requires a small amount of template DNA

e. PCR stands for "polymerase chain reaction"

f. PCR can copy the entire eukaryotic genome all at once

a. PCR can be used for amplifying a specific region of DNA

c. PCR requires heating and cooling of the reaction solution

d. PCR only requires a small amount of template DNA

e. PCR stands for "polymerase chain reaction"

Which cellular process is PCR most similar to?

a. transcription

b. DNA replication

c. translation

d. RNA splicing

Where does PCR occur?

a. in a test tube in the lab (in vitro)

b. in cells (in vivo)

In order for PCR to work, what do you have to know about the DNA template you are using?

a. the sequence of the entire DNA template

b. how many G's and C's are in the template

c. the sequences on either side of the region of DNA you want to amplify

d. you don't have to know any sequences of the template

Which of the following are reagents (enzymes or substrates) used in PCR? (Choose ALL correct answers)

a. DNA polymerase

b. dNTPs

c. helicase

d. primase

e. primers

f. DNA template

a. DNA polymerase

b. dNTPs

e. primers

f. DNA template

If you start with just one copy of template DNA in PCR, how many copies will you have after 10 cycles (if it works perfectly?)

a. 2¹⁰

b. 10²

c. 4¹⁰

d. 10⁴

What is an allele?

a. one form (or version) of a gene

b. a measurable, observable trait

c. a generation of offspring

d. the mating of two heterozygotes

What is a genotype?

a. the allels an individual carries for a particular gene

b. a measurable, observable trait

c. one form (or version) of a gene

d. having two of the same traits

What is an autosomal gene?

a. a gene found on any non-sex chromosome

b. a gene found on the X-chromosome

c. a gene found on the Y-chromosome

d. a gene found on any chromosome

What does it mean to be heterozygous for a gene?

a. you have different alleles of a gene

b. you have the same alleles of a gene

c. you have parents with different phenotypes

d. you have parents with the same phenotype

What does "electrophoresis" mean?

a. "electricity-moving"

b. "making holes"

c. "DNA seperation"

d. "gel matrix"

When DNA strands are separated in a gel using electrophoresis, which of the following will be TRUE? (Choose ALL correct answers)

a. strands will move towared the positively charged electrode

b. longer strands will move more slowly

c. each "band" on the gel will be the width of the DNA strand

d. a "ladder" of DNA strands of known sizes is embedded in teh gel before electrophoresis starts

a. strands will move towared the positively charged electrode

b. longer strands will move more slowly

Can DNA or RNA strands separated by gel electrophoresis be visualized?

a. yes, if you detect them by using a nucleic acid stain or a labeled probe

b. yes, if you have enough strands

c. no, they cannot be visualized

What does "polymorphic" mean?

a. many forms

b. lots of copies

c. slow expression

d. crazy phenotype

What is a genetic locus?

a. a genetic locus can be any sequence of DNA on any chromosome

b. a genetic locus has to be a gene

c. a genetic locus has to be dominant

d. a genetic locus is a type of flower

All of us have alleles of loci that are polymorphic.  How many different alleles of a polymorphic locus can each of us have?

a. 2

b. only 1

c. 4

d. 100s or more

What is the maximum number of different alleles of a gene that an individual human can have?

a. 2

b. 1

c. 10

d. more than 100

What is the maximum number of different alleles of a gene that the human population can have?

a. more than 100

b. 2

c. 1

d. 10

If two genes are on the same chromosome, can they segregate independently at meiosis?

a. yes, if recombination occurs between the two genes during meiosis

b. yes, if the alleles of the genes are the same

c. no, the alleles of those genes will always segregate to gametes together

d. yes, if recombination does not occur between the two genes during meiosis

Which descriptions apply to two different alleles of the same gene?  (Choose ALL correct answers)

a. they are found at the same specific location on the same type of chromosome

b. they are both sequences of nucleotides

c. one allele always "dominates" another

d. two different alleles may code for the same protein sequence

a. they are found at the same specific location on the same type of chromosome

b. they are both sequences of nucleotides

d. two different alleles may code for the same protein sequence

What is the human ABO phenotype (blood type) based on?

a. the size of the red blood cell

b. the type of sugar on the extracellular side of a membrane protein in red blood cells

c. the number of mitochondria each red blood cell has

d. the ability of the red blood cell to carry oxygen

What is always true about a dominant allele? (Choose ALL correct answers)

a. it leads to the wild-type phenotype

b. it's phenotype is seen in a heterozygote

c. it codes for a functional protein

d. it is the most common allele

What is true about the I^A and I^B alleles for the ABO gene?

a. IA is dominant over IB

b. both alleles are recessive to the i allele

c. they are codominant

d. IB is dominant over IA

Based on your understanding of gene expression (transcription regulation), what is the best explanation for a gene with two alleles that show incomplete dominance?

a. one allele is expressed in each cell at random

b. the "recessive" allele is not seen in the heterozygote's phenotype

c. there is an intermediate amount of functional protein in the heterozygote

If two unaffected parents have a baby with a single-gene genetic disease, what can you conclude about the allele that causes the disease?

a. the disease allele is recessive to the wild-type allele

b. you cannot conclude anything

c. the disease allele is dominant to the wild-type allele

d. the disease allele is co-dominant with the wild-type allele

What type of molecule is an antibody?

a. protein

b. nucleic acid

c. carbohydrate

d. lipid

What is an antigen?

a. any molecule (or part of a molecule) that initiates an immune response

b. protein

c. a non-protein molecule that is bound by the variable region of an antibody

d. an antibody that has no constant region

How many polypeptides are there in one B-cell receptor?

a. 1- one heavy chain bonded to a light chain with a peptide bond

b. 4- two heavy chains and two light chains

c. 2- one heavy chain and one light chain

d. 4- three heavy chains and one light chain

How many different genes code for a complete B cell receptor?

a. 2

b. 1

c. 3

d. 4

What is the difference between the antibodies produced by a B cell and the B-cell receptors the same cell makes?

a. the antibodies are identical to the B-cell receptors except they lack the transmembrane domain

b. nothing

c. the antibodies have different variable regions that the B-cell receptors

d. the antibodies have only one light chain bound to two heavy chains

What is true about "DNA recombination" in B-cells? (Choose ALL correct answers)

a. it is the "splicing" out of sections of DNA during B cell maturation

b. it creates a huge number of different B-cell receptors in different B-cells

c. it is the same as RNA splicing

d. it is a cutting and pasting of different polypeptide chains

a. it is the "splicing" out of sections of DNA during B cell maturation

b. it creates a huge number of different B-cell receptors in different B-cells

When a B-cell is "activated" by the binding of an antigen to its B-cell receptor, which of the following are part of the immune response? (Choose ALL correct answers)

a. the cell goes through mitosis

b. some of the daughter cells become "memory" cells and stick around for a long time

c. some of the daughter cells become plasma cells and start to make a lot of free antibody

d. the B-cell goes through somatic hypermutation to "fine tune" the antibody to the specific antigen

a. the cell goes through mitosis

b. some of the daughter cells become "memory" cells and stick around for a long time

c. some of the daughter cells become plasma cells and start to make a lot of free antibody

d. the B-cell goes through somatic hypermutation to "fine tune" the antibody to the specific antigen

After exposure to an antigen and having a normal immune response, what happens if the body is exposed to the same antigen a second time?

a. the body's second response is faster and stronger (more antibody produced)

b. the body cannot make antibodies to that antigen ever again

c. the body's second response is identical to the first

d. the body sees the antigen as self and does not attack the pathogen

What does it mean when two genes are "linked"?

a. the two genes are close together on the same chromosome

b. the two genes are on different chromosomes

c. the two genes code for proteins with similar functions

d. the two genes are inherited from the mother

What is a "genetic map"?

a. a map of the relative positions of genes (or any genetic loci) on a chromosome

b. a map of different alleles of the same gene

c. a map of all of the alleles in a population on a chromosome

d. a map of all disease gene locations

What are "genetic maps" used for?

a. finding the approximate locations of disease genes that are "linked" to a locus

b. determining the genotype of a person for a disease

c. determining the phenotype associated with different loci

d. finding the best treatment for a disease

Why was the large family that Dr. Nancy Wexler studied so useful? (Choose ALL correct answers)

a. it was a very large family in which many were descended from a single man who had Huntington's Disease

b. members of the family were willing to donate DNA samples

c. Huntington's Disease was only found in a few people in the family

d. the sequence of the disease was known by the members of the family

a. it was a very large family in which many were descended from a single man who had Huntington's Disease

b. members of the family were willing to donate DNA samples

On which chromosome did Dr. Wexler's team find a genetic marker that was linked Huntington's Disease?

a. chromosome 4

b. chromosome 10

c. the X chromosome

d. the Y chromosome

What is different between disease and normal alleles of the Huntington's disease gene (IT15)?

a. the HD alleles have more CAG codons than normal alleles

b. the HD alleles have fewer CAG codons than normal alleles

c. the HD alleles are not expressed

d. the HD alleles are expressed more often than normal alleles