Shared Flashcard Set


BIO Final
Undergraduate 1

Additional Biology Flashcards














Law of Independent Assortment


Character- A heritable feature that varies among individuals such as flower color


Trait- one of the variety of possibilities for a character.


Hybridization: The mating or crossing of two true breeding varieties.


Testcross- Breeding an organism of unknown genotype with a recessive homozygote to reveal the genotype of the first gamete.


Law of Independent Assortment- states that each pair of alleles segregates independently of the other pair during gamete formation.




Who was the first person to study genetics? How did he do it?


Experimental Design?


Heredity- The tendency for traits to be passed from parent to offspring


Gregor Mendel was the first person to study genetics, he's an Austrian Monk who worked w/ garden peas because they are easy to breed, produce a lot of offspring, and reproduce often.


Experimental Design-

 Mendel had 7 characteristics, each of which has two distinguishable traits, he let each variety self- fertilize first to ensure true- breeding.


Mendel Model (4 laws)

First Law- Alternative versions of genes account for variations in inheirited characteristics.

        Alleles= alternative forms of genes


Second Law- For each character the individual receives two alleles, one from each parent.


Third Law- When the two alleles differ for the same gene the dominant trait is displayed over the recessive one.


Law of Segregation- Two alleles for a heritable trait character seperate during gamete formation.


What carries genes?


Where are the two identical genes found on this thing?


Principle of Segregation




the locus


Principe of segregation- Each gamete carries only one allele for seed shape, because alleles have separated during meiosis.


Law of Independent Assortment


Dihybrid  Cross Generalities


- Each pair of alleles for one gene segregates into its gametes independently of the alleles from the parent's gene.


- In a cross between two dihybrinds ( two individuals heterozygous for two genes), the offspring will have four phenotypes in a 9:3:3:1 ratio.


How Genes Influence Traits

Primary Transcript- What are the genes encoded with?


How many genes does a chromosome carry?


Human Genome- how many nucleotides, form how many chromosomes.


How many different Chromosomes are their Total?


Primary Transcript- Each gene is encoded for the amino acid sequence for the protein it's designed to make


Each chromosome carries around 1,000 genes.


the Human Genome is composed of 3 billion nucleotides arranged to form 23 chromosomes, every person has 2 sets.


- There is 24 types of chromosomes, 22 autosomes, and 2 sex chromosomes, X and Y.


Genotype vs Phenotype


Frequency of traits appearance, is it relevant to anything?


Genotype= an organism's alleles

Phenotype= Manifestation of genotype, or how the genotype is expressed in the organism


- No relevance to occurance of traits in population, recessive traits are sometimes more frequently seen.



Human Genetics


- What can you use to study the passing down of traits?

- Pedigrees- This family analysis can be used to deduce the possible genotypes of individuals and make predictions about future offspring.  If a trait is passed down it's probably dominant.

Sickle Cell Anemia


Cystic Fibrosis


Huntington Disease




Sickle Cell Anemia- Recessive-  Problem with the cell's ability to carry oxygen. The frequency of this is 1/12 in the African- American Population.


Cystic Fibrosis- Affects mostly White people of European descent.  This occurs from a defective Ion channel. It's recessive. occurs in 1/30


Results in descreased osmosis, and thick mucus forms in lungs and other organs.


Huntington Disease- Neurons die and you do too within 10 years. It's a dominant trait, but only 1/10,000 humans have it.


Multiple Alleles, Incomplete Dominance and Co- Dominance,


Blood Types


Incomplete Dominance- Neither allele is completely dominant.


Co- dominant- occurs when a gene has several allels and some are co- dominant to each other, like blood types.


In blood their is iA, iB, iAB, or ii, only ii is recessive, all the other traits are co- dominant to each other.


Sex linked Alleles

- The chromosomal basis of Sex.


- The inheritance of Sex- Linked Genes.


- X inactivation in Female Mammals.


- Sex- Linked Alleles pattern


- Are disorder with sex chromosomes more likely to be associated with men?


The chromosomal basis- The sex of an individual is derived by which sex chromosomes are present.  Humans sex system works with X-Y, but other animals use different systems.


Inheritance of Sex- Linked Genes- The sex chromosomes carry genes for some traits that are unrelated to sex characteristics.  For example color blindness with males.  Fathers can give color blindness as a recessive trait to his daughters, but a son can only catch color blindness if his mother has or carries it.


- Sex linked genes have different patterns of inheritance than autosomal genes.  The Y chromosome is blank for these genes.


- Yes, but the disorder needs to be from a recessive gene.


 The Sex of a child is determined by what?


Polygenic Phenotypes


- A child's sex is determined by the sex chromosome that the father gives to his sperm.


Polygenic Phenotypes- Phenotypes determined by more than several genes, with each gene possibly having several different alleles.

- The alleles of each gene together determine the phenotype, so their is no discrete phenotype. and Continuous Variation occurs.

(Example Human Height)


Linked Genes

what's different if genes are on same chromosome


what importance does distance between two genes on the same chromosomes have


Crossing Over


linked genes- two or more genes on a single chromosome, the genes are often inherited together


If the genes are on the same chromosome they are linked, This means that assortment is NOT INDEPENDENT, and you have less possible genotypes in offspring ( two 1/2's, instead of four 1/4's)


-These genes since they are on the same chromosome travel together during meiosis.


- The closer two genes are on the same chromosome the less likely they are to cross- over, the further aparty they are on the same chromosome the more likely they are to cross over.


Crossing Over- the separating of linked genes found at ends of chromosomes.



Genetic Recombination- what is it and where/when does it occur?
Genetic Recombination- occurs when new combinations of traits appear in the offspring that weren't found in the parents. This occurs from the crossing over between nonsister chromatids during meiosis 1.



what is it composed of





DNA- Deoxyribonucleic Acid

- polymer of nucleotides joined by phosphodiester bonds that consists of a Nitrogenous Base (either T,A,C,G), The sugar ( Deoxyribose), and a Phosphate Group.

A= adenine

T= Thymine

G= Guanine

C= Cytosine

Double Helix of Antiparallel strands, strands are held together by H- Bonds



RNA= Ribonucleic Acid



Who was DNA's structure found by? how?


What are the Purine Pyrimidine pairs?


When predicting opposite DNA or RNA strand make sure to flip the 5' to 3', or vice versa!!


- DNA was found by Rosalind Franklin using X-Ray crystallography.


- the purine pyrimidine pairs are: A-T, and G-C, they are called complementary bases.

Which 3 things are required for DNA Synthesis?

Three Requirements:

1. Single Stranded DNA (ssDNA)

2. Enzyme and nucleotides

3. Primer to provide a starting point.


DNA Synthesis (6 Steps)


Single Strand Binding Proteins


What relieves the stress from the twisted DNA Helix?


What direction is the new DNA molecule synthesized in?



1. orgins of replication are found by a primer, which will open the double helix at the orgin site.


2. Once DNA helix is open Helicase helps open it further, creating a replication fork, which is essentially a bubble that grows.


3. At the beginning of the template strands primers are formed from RNA primase, this is necessary for DNA Polymerase to work.  The leading strand receives only one Primer, but the lagging strand receives several (Okazaki.)


4. After the primer DNA Polymerase 3 adds nucleotides to the 3' ends of the two strands.  The leading strand is built upon in one motion, but the lagging strand is formed in bits and pieces because of the several RNA fragments.


5. DNA Polymerase then goes in and removes all the RNA fragments, replacing them with DNA.


6. But there are still several nicks in the lagging strand and one in the leading strand, they are taken care of by DNA Ligase.




Single Strand Binding Proteins from on the newly split DNA's strands, stabilizing them while keeping the DNA from re- closing.


Topoisomerase- relieves the stress from the unwound portion of the DNA Helix.


- Afterwards the DNA Polymerase checks for errors, if any are found too late then it's up to enzymes to remove them.


- The new DNA molecule is synthesized in a 5' to 3' motion.


Transcription= (Basic Meaning)


2 requirements of Transcription


Differences between DNA Replication and Transcription


Transcription= RNA synthesis



1. Single Stranded DNA

2. Enzyme and nucleotides



Transcription used U instead of T

- uses nucleotides containing ribose instead of deoxyribose


RNA Transcription





the Enzyme RNA Polymerase must find and bond with w/ a core promoter and with Transcription Factors (Proteins) to form the Transcription Elongation Complex.


Elongation- The template strand of DNA is traveled down by the RNA Polymerase which creates Bases to coordinate with the DNA strand, the new strand is build upon in the 5' to 3' direction.


The new copy has Uracil instead of thymine.


When finished three A's are added to the tail ceasing the RNA copying, this process is called Polyadenylation.




RNA Processing


how do the two modifications help?


RNA Splicing


RNA Processing: during this process both ends of the primary transcript are altered.


5' cap added composed of G

3' Tail added composed of 50-250 A's



1. Helps export mRNA from nucleus.

2. Protects mRNA from dehydration.

3. Helps ribosomes attach to the 5' end.


RNA Splicing

Introns= get removed from RNA Copy

Exons= pieces get spliced together once Introns are gone.










What's the Translation Initiation Complex?


3 Sites of a Ribosome.



Initiation: Small subunit of ribosome binds RNA
First tRNA (carrying f-Met) binds AUG start codon
Large subunit of ribosome binds to the small subunit

mRNA carries its genetic information as a ribonucleotide sequence as it travels towards the tRNA.


The mRNA has its codons read and is then matched with the appropriate Anti- Codon of a tRNA, which has an AA attached to its other side.


The tRNA then passes through the rRNA of the ribosome and releases its AA.

-The ribosome then strings the AA's together in the appropriate order, forming the polypeptide chain.


When a stop codon appears the codon binds with release factors which stop the forming of the polypeptide chain, and allows it to break lose.


Translation Initiation Complex: mRNA+tRNA+ 2 ribosome units.


Sites of Ribosome:

P Site= Polypeptide Chain

A Site= tRNA with AA yet to enter Ribosome

E Site= tRNA leave here after passing through Ribosome



Protein Reading Frames

- Reading Frames: Start one more nucleotide over for each row down when you begin reading the sequence.


-Remember to always start at the start codon and stop at the stop codon, if doing this by hand.







Substitution: Replacing one base with a different base.


Frameshift mutations: occurs when nucleotides are inserted or deleted.

Start Codons and Stop Codons

Start= ATG, or AUG

Stop = TAA, TGA, TAG, or UAA, UGA, and UAG

Restriction Enzyme

- Enzymes that recognize specific sequences of nucleotides in DNA, and cut them.


- This helps determine possible mutations, because the mutation sequence will not get cut, like the wild type will.


Gene Expression




Primary Transcript


Triplet Code


Gene Expression= process by which DNA directs the synthesis of proteins


Monomers= A,T,C,G


Primary Transcript= The original copy of mRNA before splicing and stuff.


Triplet Code= The genetic information to form AA's/ the polypetide chain is derived from sets of three nucleotides from the mRNA


Cellular Respiration

4 main steps


Total energy released per 1 ATP of glucose at end of Respiration is what?


Glycolysis- takes place in cytoplasm

oxidizes glucose into 2 pyruvate (costs 1 ATP)

Energy Payoff= 2 ATP+ 2 NADH net difference from the oxidizing of glucose.

Krebs Cycle or Citric Acid Cycle

-Glucose is further oxidized by changing the pyruvate to CO2.

1. pyruvate enters mitchondrion where its further oxidized

2. The mitochondrion creates Acetyl CoA (gives E-'s to NAD+ and FAD+) from pyruvate.

3. E-'s from oxidized pyruvate are given to NADH's

4. As the pyruvate is broken down 2 CO2 molecules are released.

5. 2 ATP is generated again, but most energy goes to NADH and FADH2 to the ETC


1. ETC accepts all the E-'s from NADH's from first 2 steps.

2. These E-'s get passed down the chain to more electronegative molecules.

3. O2 is the final accepter and it forms with E-'s and H+ to make Water.

Oxydative Phosphorylation

1. H+ gradient, which was formed from ETC is used to make energy as the H+ is pumped out through ATP Synthase.

2. This process of creating ATP from ATP Synthase is called Chemiostasis.

3. Protons attach to sides of rotor causing it to spin and catalyze ATP from ADP+Pi.

38 ATP is generated from this whole process.

Meiosis 1=


Meiosis 2=


Meiosis 1= Reductive division= seperates homologs

Meiosis 2= Separates sister chromatids

- There is no g2 in Meiosis

Prophase 1

- chromosomes condense in the nuclues and become visible. crossing over occurs here in the synapse.

- Centrosomes are formed mitotic spindle.


Metaphase 1

-Homologs line up in metaphase plate.

- Centrosomes are now completely on their sides

- Kinetochores attach to Centromeres of homolog pairs and to other kinechores.


Anaphase 1

- Homologs are pulled to each side by the microtubles of the mitotic spindle connected to the centrosomes.

- Un connected Kinetochores push the cell apart extending it.

- The two cells now contain one complete set of chromosomes


Telophase 1

The cell begins to pinch


Prophase 2

Cells become visible again and new centrosomes appear with mitotic spindle.


Metaphase 2

Cells line up again on metaphase plate with kinetochores connecting to their centromeres and the kinetocheres also connect to themselves.


Anaphase 2

The sister chromatids begin to get pulled to their respective sides from the kinetochore.

Supporting users have an ad free experience!