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Bio Exam 2
flashcards for getting an A on your biology exam
83
Biology
Undergraduate 2
02/29/2012

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Cards

Term
How do physical laws contstrain animal form?
Definition
  • SA:V ratio
  • blue whales are too big to live on land
  • we dont have animals like dragons because the wings are too small to hold such a giant body mass
  • insects can't be too big because the exoskeleton would eventually not be able to hold it
Term
How does surface area to volume ratio influence total organismal size? How does it affect exchange with the environment?
Definition
  • Smaller animals have a higher SA:V ratio than larger.
  • Body surface area increases with square of body length
  • mass increases with cube of body length. as you get longer, you get much heavier
  • SA:V ratio effects circulation, respiration and temperature regulation
Term
When is diffusion good enough? Refer to circulation, digestion and respiration.
Definition

Circulation: for very thin or very small organisms. It is cheap with very little/ no ATP expenditure. Single celled protists. Since diffusion takes a long time, it has to be a high SA:V ratio

Respiration: same thing

Term
Why are there small mammals at higher latitudes?
Definition
small mammals have a high SA:V ratio, so they can get rid of heat. Its hot at high latitudes. 
Term
What are the advantages of being an endotherm? An ectotherm?
Definition

Endotherm: metabolism can internally regulate body temperature. Able to do more things and more versatile in varying environments.

 

Ectotherms: body temperature determined by the environment. Most insects, most fish, amphibians, most reptiles. Ectothermy is very cheap in energy expenditure. (see frogsicle)

Term
What are the costs of endothermy and ectothermy? How do they vary with body size or SA:V?
Definition
Energy expenditure varys based on size and SA:V ratio. If there is a high SA:V ratio, there is less energy expenditure (diffusion). Endothermy is very costly in ATP with a low SA:V ratio.
Term
Homeostasis
Definition
  • steady state of the physiological condition of the body
  • Thermoregulation: steady body heat- Insulation, Circulation, Adaptations, Behavior, Avoidancde
  • Osmoregulation: balance between water and salt in body
Term
Counter Current Heat Exchange
Definition

related to homeostasis

-arteries and veins are proximal in animal appendages, heat goes from the artery blood to the vein blood to make appendages warm.

Term
What are the different strategies of temperature variation? Examples
Definition

1) Insulation: skin, fur, feathers, fat, blubber, goosebumps (trap air under our hairs)

2) Circulation: vasodilation and constriction, counter current heat exchange

3) Adaptations: panting, sweating (cools down), mucous?

4) Behavior- migrating, huddling, basking (ectotherms can be homeotherms because of behavioral changes)

5) Avoidance: Torpor- physiological state where metabolism slows way down, low activity. Hibernation (winter) and Estivation (summer)

Term
Why do we eat?
Definition
  • To obtain energy (ATP!)- monomers of proteins, carbs and fats
  • Biosynthesis- growth and reproduction, carbon and nitrogen, storage (definition- building complex compounds from monomers)
  • Essential Nutrients: 1- Amino Acids 2-Fatty acids 3- Vitamins 4- Minerals
  • Our body needs 20 proteins, 8 of which are essential,   meaning from the diet
  • There are 13 essential vitamins serving as coenzymes
Term
Essential Nutrients
Definition
  • Body needs 20 proteins, 8 essential
  • Fatty acids- membranes and hormones (unsaturated are double bonded carbonds, saturated are fatty acids saturated with hydrogen)
  • Vitamins- needed in lower amounts, serving as coenzymes. there are 13
  • Minerals- inorganic compounds- calcium, phosphorus, iron, magnesium. enzyme cofactors. *Osteophagy is when animals eat animal bones to get essential minerals
  • Scurvy: Vitamin C deficiency- spongy gums, bleeding membranes
Term
Dentition and Digestion in Different Animals
Definition
  • Carnivors: Incisors (front), Canines (next), premolars and molars. clearly for ripping apart flesh
  • Herbivores: incisors and a big gap to their premolars, small or no canines
  • Omnivores: all in a row, canines that aren't as sharp
Term
How do you expect animal systems to differ as a function of diet?
Definition
  • Carnivores: short intestine, small cecum, shorter colon- don't have to digest plants, which are harder to break down
  • Herbivores: big ol cecum, really long colon and intestine for breaking down plants
  • Cecum: home for symbionts to break down cellulose
Term
What are essential amino acids?
Definition
There are 8 essential amino acids, and the others can be synthesized from these 8
Term
What can go wrong with improper nutrition?
Definition

Scurvy: Vitamin C deficiency

 

Term
Ingestion
Definition
  • takes place in mouth and esophagus
  •  eating
Term
Digestion
Definition
  • break down of food into molecules usable by the cells
  • begins with saliva in the mouth- salivary amylase breaks down starch and glycogen (small carbohydrates)
  • then to the stomach, where enzymes, such as pepsin and highly acidic gastric juice which are important in protein digestion. Stomach also stores food.
  • Positive feedback- pepsin can make more pepsin from pepsinogen
  • Negative feedback- H+ breaks down gastrin to stop the process
  • PNS->Gastrin> H+, Pepsinogen, Mucus> Pepsin
  • Small intestine breaks down food into molecules usable by cells (6 mtrs long in small intestine)
  • Pancreas produces digestive enzymes
Term
Absorption
Definition
Term
Absorption
Definition

Occurs in the small intestine 

  • digested molecules must enter the body
  • small intestine is very folded has has a large SA to accomplish this
  • Villi and microvilli- folds on folds. these aid in the absorption
Term
Elimination
Definition

occurs in the large intestine

  • concludes food processing
  • very important in water processing
  • borrows 90% water from circulatory system. If it doesn't give enough back, diarrhea. If it gives too much back, constipation
Term
How does the small intestine increase its surface area?
Definition
folding, villi, and microvilli
Term
How do other organs play a supporting role in the digestive process?
Definition

Pancreas: produces digestive enzymes, such as trypsin, chymotrypsin, carboxypeptidose (polypeptides -> amino acids). Nuclease: nucleic acid->nucleotides; Amylase: polysaccharides-> disaccharides; Lipase: fat drops->glycerol-> fatty acids Pancreas aids in the break down of main nutrients.

Liver: detoxifies alcohol and other toxins, releases bile salts to break up fat globules

Term
TFO: Frogsicle
Definition
  • Wood frog. A picture of a frog completely frozen but not dead- the only amphibian in the arctic circle (Alaskan tundra)
  • Freezes. No breathing, heart stops and organs dehydrate. Use glucose and urea as a cryoprotectant - they don't freeze! 
  • It's extremely cheap! When its outside environment warms up, it thaws out and goes on with its life!
Term
TFO: Bugs eating poop
Definition
  • Coprophagy: consumption of poo
  • Why do some animals do this? inefficient digestion, herbivores trying to get nutrients, 10% on first round?, bacteria, vitamins and nutrients (fermentation and symbionts) or habitat! Dung balls, bettle larva
  • Ecosystem service!
Term
What is the purpose of the circulatory system and how does it interface with the respiratory system? Digestive system?
Definition

Purpose: transport- good stuff to all cells in the body (Oxygen, essential nutrients)

Oxygen: interface of circulatory with respiratory. blood goes to the lungs to get oxygen. AKA gas exchange

Essential nutrients: interface of circulatory with respiratory. Blood takes the nutrients from digested food in the small intestine 

Term
Type of circulatory system- Diffusion
Definition
  • occurs in cnidarians, flatworms, single celled protists
  • benefit: very cheap, requires no ATP- sufficient in very thin animals with high SA:V ratio
  • takes a long time: diffusion ~ distance^2
Term
Type of circulatory: Open Circulatory System
Definition
  • happens in arthropods and most molluscs
  • bathes organs directly without blood vessels
  • hemolymph: pool of blood that bathes the organs
  • more pricey than diffusion, still really cheap
  • no high blood pressure system
Term
Type of Circulatory: Closed
Definition
  • blood inside a very extensive vessel network of arteries, veins and capillaries 
  • Disadvantage: allows for greater metabolic demands: very expensive in ATP
  • Advantage: Animals with closed are larger and more active, can do more things
  • Most endotherms, most mammals, some molluscs (cephalopods), earthworms, vertebrates
Term
Heart
Definition
  • Two atria, two ventricles (powerful, muscles)
Term
What kind of blood occurs in the right and left atria and ventricles?
Definition

Right ventricle: deoxygenated

Right atrium: deoxygenated

Left ventricle: oxygenated

Left atrium: oxygenated

Term
How do physical principles govern blood flow?
Definition

Bernoulli's Principle: rate of flow of a liquid is inversely proportional to total flow area. 

*Capillaries seem to go against this, because the flow slows way down going from arteries to capillaries. however, total area of capillaries is much bigger than that of arteries, so it does slow down. (like going from one hose to five hoses)

Term
Blood vessels: arteries, veins, capillaries
Definition

Arteries: heart-> capillaries: thicker in their wall with a greater elasticity than veins. This is because they have to handle much higher pressure

Veins: capillaries-> heart

Capillaries: venules, arterioles facilitate material exchange.  Do the interchange with digestive and respiratory. They are thin walled with close proximity and very slow flow. This allows oxygen, nutrients and waste to flow to and from the tissue

Term

Blood: Red Blood Cells

 

Definition
  • erythrocytes
  • biconcave disks (SA:V, material exchange) 
  • produced in bone marrow
  • no nucleus or mitochondria to make room for hemoglobin- releases and grabs onto oxygen at the right time. (4 heme groups with iron, which has an affinity to oxygen)
  • EPO:  hormone that promotes creation of erythrocytes. related to illegal blood doping because the more RBCs you have, the more O2 you get. 
Term
Blood: White Blood Cells
Definition
  • have a nucleus: how they get DNA from blood. 
  • plays a huge role in immune system
Term
Blood: Platelets
Definition
  • aid in blood clotting, no nucleus
  • Open wound: 1-platelets bind to collagen to form a plug 2- release clotting factor: proteins activate
  • Protein: Fibrinogen is the unactivated form of fibrin. Fibrin makes threads that compose the clot. 
Term
TFO: picture of two arteries, one with a blockage
Definition
  • Cardiovascular disease: causes of 50% of US deaths
  • Artherosclerosis: deposition of plaque in arteries. The kicker is that the plaque stimulates clotting in places you don't want to clot. Limits oxygen to heart and brain- causes heart attack
  • Care for teeth, care for heart: recent findings that link gingivitis to cardiovascular disease
  • Can it be infectious? bacteria getting into arteries and veins from open wounds
Term
What are stroke and heart attack?
Definition

Stroke: death of nervous tissue in the brain, blockage of arteries in head

Heart attack: death of cardiac muscle, prolonged blockage of coronary arteries

Term
What is the purpose of the respiratory system? 
Definition

For gas exchange. 

Why do we need gas exchange? To get oxygen, needed for aerobic respiration of monomers -> ATP

To dispose of CO2, Vocalization

Term
Type of Respiratory: Diffusion
Definition
  • Gas exchange using body surface
  • very cheap
  • needs HIGH SA:V ratio, need LOW metabolic demand
  • have to stay wet (why?)
  • eg: protists, flatworms, cnidarians
Term
Type of Respiratory: Gills
Definition
  • only aquatic 
  • easy for them to keep wet, only the oxygen content of water is much lower than that of air (about 1%)
  • Ventilation: water is moved past gills by muscular activity
  • Counter current exchange: water and blood moving in opposite directions. O2 goes out of water into blood. If they were parallel it would be much less efficient. 
  • Needs a high SA:V ratio, gill SA can exceed that of body. 
Term
Type of Respiratory: Tracheal
Definition
  • occurs in arthropods and insects who have an open circulatory system(hemolymph is not involved in gas exchange).
  • Air is lighter and O2 rich, travels through a huge network of tubes to deliver air to every single cell
  • Must keep wet with high SA:V
  • This means that oxygen transport is one of the major limitations on insect size. They can't be bigger, because that would decrease the SA:V ratio
Term
TFO: Giant Dragonfly
Definition
  • Meganeura
  • size of a small hawk
  • consumes amphibians and other insects
  • hada tracheal system- how?
  • Current O2 content- 20%, Carboniferous- 35% O2
  • Perfectly preserved Illinois rainforest- found predatory scorpions that were the size of a small car
Term
Type of Respiratory: Lungs
Definition
  • mammals, birds, reptiles, many amphibians
  • very high SA and very low diffusion distance. Lungs are highly vascularized
  • Bronchial system: network of tubes getting smaller and smaller- bronchioles -> alveolus
  • capillaries are right on top of alveoli- gas from the alveoli moves into the blood in the capillaries
  • this minimizes diffusion distance, maximizing S.A. for gas exchange.
  • Gas dissolves into the solution
Term
How do animals control breathing?
Definition
  • Medulla oblongata monitors CO2 levels by using cues from changes in pH.
  • lower pH= higher CO2 (this is why hyperventilating can be dangerous. expelling CO2 but not getting oxygen tricks your brain into thinking you're getting enough oxygen)
  • CO2 reacts with water to form carbonic acid
Term
whats the difference between trachea and lungs in relation to SA:V and gas exchange
Definition
  • in lungs, the gas dissolves into the blood
  • in trachea, the gas does not dissolve into solution, it just goes to the cells
  • lungs want to maximize surface area and minimize diffusion distance 
Term
Hemoglobin
Definition
  • increases our oxygen transport 70X- important to our survival
  • Hemoglobin is a protein with 4 subunits (hemes) containing iron- iron binds with oxygen to make oxyhemoglobin
  • It binds oxygen reversibly- high CO2 lowers the blood pH. Hemoglobin releases oxygen. Low CO2 levels raise the blood pH, hemoglobin grabs on to oxygen
Term
What changes at high altitude or underwater?
Definition

much less pressure at high elevation-> hypoxia (low oxygen)

underwater the pressure increases a lot

Term
What is the purpose of the immune system? What are the challenges involved?
Definition
To destroy unwanted cells in your body. Challenges: differentiating between the ones I want and the ones I don't want. Between good self and bad self.
Term
How does the body differentiate between self and nonself? 
Definition

MHC proteins! Very important and extremely diverse (each individual has a different MHC protein) - they are expressed on the surface of a cell, serving as an ID badge- if it lacks the badge, the immune system wants to kill it. 

The immune system would be useless without a way to differentiate between good and bad.

Term
Who are the bad guys and how do they differ?
Definition
Bacteria, Viruses, Protists and Worms (eg blood fluke)
Term
What are the different types of innate immunity? How are they nonspecific?
Definition

Skin, Phagocytes, Antimicrobial peptides, Inflammation, Natural killers

They are nonspecific because they provide general "lines of defense" against all foreign cells

Term
Innate: Skin and secretions
Definition
  • protective barrier
  • mucous membranes
  • chemical defenses such as sweat- sweat is highly acidic, trying to get in the way?
  • Injury creates and opening- way in for the unwanted stuff
Term
Innate: Phagocytes
Definition
  • Phagocytosis -"eat em!"; actually engulfs and ingests invaders
  • White Blood Cells- 3 different types: 1) Macrophage (big eaters) 2) Neutrophils (first responders), make up most of phagocytes 3) Esinophils (deals with macroparasites) 
  • Recognize via MHC proteins, but not perfect. (eg schistosoma- blood fluke mimicing our mhc proteins)
Term
Innate: Antimicrobial proteins
Definition
  • "kill em!"- proteins that chemically attack pathogens
  • Complement System: more than 30 proteins- complex cascade of proteins attacking invaders
  • Interferons: used in treatment of viral infections and cancer
Term
Innate: Inflammation
Definition

Chemical and cellular response to injury/  or localized infections

Promotes wound healing

1-Injury allows pathogen in- histomine is release, letting the immune system know

2- Blood flow increases (swelling), clotting factor is activated (phagocytes come onto the scene)

3- Wound closes, pathogen killed

Term
Natural Killer Cells
Definition
  • "dissolve em!" 
  • These cells destroy viral infections and cancerous cells 
  • They "lyse" or break open the infected cells
  • They are actual cells instead of proteins or something else
Term
Acquired: Antibody Mediated Response
Definition

-B cells and antibodies, mature in the bone marrow, 

  • antigens: forgein proteins/ complex sugars. -isolated molecules, toxins, fragments of bacteria
  • Produce antibodies in response to antigens
Term
How do antibodies acheive such diversity?
Definition
the body makes millions of variations of antibodies in anticipation of antigens- produced in fetal tissues 
Term
Acquired: Antibody mediated: What is clonal selection? 
Definition

Two types: 1)Effector Cells: plasma cells, short lived cells to comobat antigen, they are the initial defense

2) Memory cells: long lived, secondary response. can respond rapidly and strongly to a second exposure to the antigen. The whole idea behind vaccination.

Term
Acquired: Cell mediated: Helper T cells vs Cytotoxic T cells
Definition
  • Helper T cells: first response to antigen presenting cells, stimulates proliferation of B cells and Cytotoxic T cells
  • Cytotoxic T Cells: identify and destroy cells- expose pathogen to the rest of the immune system to kill it.
Term
Acquired: Cell mediated
Definition
  • T cells respond to antigen fragment presented on surface of body's cells 
  • Deals with intracellular virus 
  • T cells mature in the thymus
Term
What is vaccination? How does it work and when does it not work? 
Definition
  • activating memory cells (secondary immune response) to weakened version of pathogen - related to less pathogenic, killed or weakened toxins
  • how smallpox was erradicated 
  • flushot and HIV only within year protection
  • HPV most common STI: cervical cancer, throat cancer, genital warts
Term
TFO: Super spreaders
Definition
  • new research showing that not all individuals are equally infectious. 80/20 rule- 80% of infected people are infected by 20% of people already infected (based on a lot of things- lifestyle, profession, etc)
  • Typhoid Mary: unsanitary cook in early 1900s- linked to 47 cases of typhoid. She was a healthy carrier- didn't feel sick but was infected with typhoid. They put her on an island.
  • Esther Mok: SARS (severe acute respiration syndrome) 100+ infections linked to this 26 year old flight attendant.
Term
How does HIV work? Why does it compromise the immune system?
Definition
HIV takes over certain T cells that really help you fight bad things. It takes them over and starts replicating so instead of making more T cells, they make more HIV
Term
Osmoregulation
Definition

balance between salt and water in the body

movement of water or solutes

keeps the good, loses the bad

Good: water, nutrients, vitamins

Bad: salt, nitrogenous bases

Term
What are hypertonic, hypotonic, and isotonic?
Definition
  • Hypertonic: net water loss, cell dessicates and crashes in on itself. dries out.
  • Hypotonic: net water gain, cell swells and often ruptures
  • Isotonic: no net loss/gain
Term
How do animals deal with this? What if you move them to a new environment?
Definition
  • marine environments are hypertonic (more solutes in the water) the animals drink lots of water to get the water and pee concentrated urine. 
  • freshwater is hypotonic- plenty of water, less solutes, pee a lot of dilute urine
  • terrestrial- dessication. terrestrial animals need to conserve water at all costs: they use many different things for this: skin, exoskeleton, waxy cuticle, shell
Term
What are the forms of nitrogenous wastes? Costs and benefits? what kind of animal will have each one? 
Definition
  • Ammonia: extremely toxic, but is soluble in water. Animals with access to water are more likely to excrete ammonia as waste, so they can get rid of it quickly. (Fishes and aquatic insects)
  • Urea: much less toxic than ammonia. mammals, turtles and adult amphibians excrete urea. Land animals have it because they need to be able to store it. They can't just leak all the time. (energetically expensive)
  • Uric acid: "salt snot" excreted by birds (out the nose), insects, reptiles. Not soluble, but a semi solid paste, very expensive to make. Made by animals needing to conserve water. 
Term
Kidneys
Definition
  • extremely important: allow for life on dry land
  • 1500 L of blood per day are filtered by kidneys- eliminates toxic waste, 99% of water, vitamins and sugar
  • highly expensive metabolically
  • Uses nephrons to filter (about 80 km of tubules). They filter blood, reabsorb thing we want to hold on to, excrete
  • Filtration: removing waste through the nephron on to urine
Term

Nephrons: important parts and their functions

 

Definition
  • Glomerulus: ball of capillaries where blood is filtered
  • Bowman's capsule: entrance to nephron- water and solutes are transferred from blood to here
  • Loop of Henle: important- descending and ascending limb where water and solutes are reabsorbed. (descending pulls water, ascending pulls salt)
Term
what is the importants of selectively permeable membranes in nephrons?
Definition
To absorb the good stuff and excrete waste with as little water loss as possible
Term
when are salts lost? when is water lost?
Definition
  • Descending limb of loop of henle loses water
  • Ascending limb loses salts
Term
Understand the importance of ADH in regulating water balance.
Definition

ADH: hormone. brain makes ADH, which go to nephrons and tell them to produce more concentrated urine, tells them to take more water out of the blood. 

ADH basically tells kidneys to pull more water.

What does alcohol do to this process? Suppresses ADH, causing you to dehydrate. Diuretic.

Term
What happens when the kidneys malfunction?
Definition

Gout: accumulation of uric acid, often stored in joints

Kidney stone

Term
Asexual reproduction
Definition

Offspring identical to single parent

No meiosis

No fusion of sperm or egg

Rapid and cheap

Loss of possible genetic diversity (no crossing over or recombination)

Term
4 Types of Asexual Reproduction
Definition

Budding: plants, fungi, cnidarians, worms

Fission: unicellular- protists, prokaryotes, eukaryotic organelles (chloroplasts), sea anemones- basically rips in half

Fragmentation: unintentional- animal needs to be able to regenerate- fungi, plants, sponges, cnidarians, sea stars, annelids

Parthenogenesis: females producing offspring from an unfertilized egg- parthenogenesis and sexual reproduction can take same in some species or even one individual!

Term
TFO: Komodo Dragon
Definition
  • Parthenogenesis: Komodo dragon named Sungai was isolated for two years, but laid eggs that actually hatched!
  • Offspring can only be male
  • Females are ZW genes
Term
Why have sex? Is sexual reproduction an evolutionary stable strategy?
Definition

Yes- sex creates more variable genetics- ability to adapt

Protection from mutations

Sex is extremely expensive- energy, time and resources. Dangerous to seek mates

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