AP Bio Final Study Guide
Some fish species live in areas where sea and fresh water mix. Discuss what challenges animals who live in this brackish water environment face in terms of their osmoregulation.
-may be isotonic (isoosmotic) and not have a problem - may have to shift between hyper and hypo-osmotic situations -may have to swim or find areas that they can tolerate as the water types mix-other acceptable answer
Write the basic equation for Photosynthesis
6 CO2 + 6 H2O C6H12O6 + 6 O2
Discuss why HIV is deadly and difficult to control.
AIDS is deadly because it destroys the CD4 helper T cells crippling the humoral and cell-mediated immune systems. The body is open to opportunistic infections. The virus mutates very rapidly. Rapid antigenic changes of HIV complicates development of a vaccine.
Contrast and compare an absorption spectra versus an action spectra for Ps.
Absorption spectra - the wavelengths of light that are captured by the pigments. Action spectra - the wavelengths of light that are actually used by photosynthesis
Neurotransmitters include several different chemicals. Identify four neurotransmitters and describe if they are excitatory (2 examples) or inhibitory (2 examples)
Acetylcholine (usually ex), biogenic amines such as norepinephrine (both), dopamine (usually ex), serotonin (usually inhibit); amino acids such as GABA (inhibit), Glycine (inhibit), Glutamate (ex); neuropeptides such as substance P (ex), Met-enkephalin (usually inhibit); gases such as nitric oxide (both)
Describe how drinking alcoholic beverages may actually increase dehydration.
Alcohol inhibits the release of ADH causing excessive urinary water loss and dehydration
Identify the two "types" of monosaccharides and discuss how they differ in structure.
Aldose and Ketose and the position of the carbonyl group.
Identify what the formation of all macromolecules from monomers has in common.
All are made by the same reaction, dehydration synthesis or condensation reaction.
Describe how variable splicing of DNA is used in the immune system.
Alternative splicing of RNA transcripts allows variation in making antibodies
Excess nitrogen in animals is secreted in three various forms of toxic waste. Correlate the chemistry of each toxic waste to the lifestyle and/or environment of the animal.
Ammonia - water soluble, toxic in low concentrations - aquatic animals Uric acid - not water soluble or toxic - birds insects, reptiles, land snails (animals with shelled eggs or live in drier habitats) Urea - water-soluble but not toxic - mammals, most amphibians, sharks (require less water for excretion so may live in drier areas)
Compare the excretory system in terms of structure and function from the simple animal to more complex animals.
Amoeba - flatworm - earthworm - insect - vertebrate Amoeba - simple diffusion and osmosis through the cell membrane Flatworm - protonephridium and flame bulb cells, dead end tubules Earthworm - metanephridia with internal openings to collect body fluids Insects - Malphigian tubules with dead end tips and open to the digestive tract Vertebrates - nephrons in kidneys use passive and active transport All are involved with removal of waste and osmoregulation
Describe the role of oxygen in cellular respiration
As a final electron acceptor.
Describe the differences between the antigens that B cell receptors and antibodies recognize, and the antigens that T cell receptors on cytotoxic T cells and helper T cells recognize.
B cell receptors and antibodies recognize intact antigens. T cell receptors recognize pieces of antigens that have complexed with an MHC molecule and are presented on cell surface7.
Why is the process of chemiosmosis also called a proton-motive force?
Because energy is use to move protons across membranes to create a concentration gradient. It is the concentration gradient that can be tapped to do work.
Is binary fission the same as mitosis? Explain.
Binary fission is the division of a prokaryotic cell which lacks a nucleus. Mitosis is the division of the nucleus of a eukaryotic cell. They are not the same thing.
In science fiction stories, plants that live on planets far from the sun are often described as having black foliage, while those that live on planets close to the sun are described as having shiny reflective foliage. Discuss why these would be good adaptive features.
Black foliage means that no light is being reflected or transmitted and all light energy is being absorbed. Light levels would be lower further from the sun, so trapping all of the available light energy would be adaptive. Shiny foliage means that light energy is being reflected. Light levels would be higher closer to the sun and could damage the plant. Reflecting away extra light to prevent damage would be adaptive.
Small cuts that open blood vessels and bleed often heal faster than cuts that don't bleed (e.g. paper cuts). Using your knowledge of factors that affect cell division, speculate on a possible mechanism for why this occurs.
Bleeding brings platelets to the area to form blood clots. The presence of platelets places the cell division stimulate PDGF in the cut. PDGF would stimulate cell division and close the wound faster.
Write the basic balanced equation for cellular respiration.
C6H12O6 + 6 O2 6 CO2 + 6 H2O + energy
Describe examples of experimental evidence that support the hypothesis that membrane proteins drift or move over time.
Cell fusion studies, fluorescent markers, other relevant example
Identify several cell structures are common to both prokaryotic and eukaryotic cells.
Cell membrane, ribosomes, DNA (genetic information), cytoplasm
Several years ago, a meteorite was found from Mars. Upon SEM examination, objects that looked like prokaryotic cells were found in the interior. This discovery caused a major splash in the scientific community. Discuss why this was so
Cells are the basic unit of life. If the objects were cells, this was evidence of past life on Mars (or extra-terrestrial life).
When the cytoskeleton was first discovered, scientists thought what they were seeing were artifacts of the TEM. Discuss why shouldn't they have been surprised to find the cytoskeleton. (e.g. why is a cytoskeleton necessary for cells).
Cells must be supported against gravity, cells need places to attach or hang organelles, cells need internal transport mechanisms etc.
Identify what aquaporins are and discuss why are they important.
Channels that allow water to cross membranes by facilitated diffusion and osmosis is too slow without these channels
Many people talk about their car as if it was alive, giving it a name and regularly talking to it. Discuss what characteristics of Life DO apply to a car and which characteristics of Life DO NOT apply.
Characteristics of Life that could apply: have order and structure, use energy, response to environment regulation Characteristics of Life that don't apply: reproduction, growth and development, evolutionary adaptation, made of cells
Contrast and compare the function of the chlorophyll pigments versus the function of the accessory pigments in Ps.
Chlorophyll is the main light trap or light absorption pigment for Ps. Accessory pigments capture light at wavelengths that chlorophyll does not absorb and transfers the energy to chlorophyll for Ps.6.
Contrast and compare cofactors versus coenzymes.
Cofactors are inorganic helpers to enzymes such as Fe. Cu, Zn. Coenzymes are organic helpers to enzymes such as vitamins.
Contrast and compare competitive inhibitors with noncompetitive inhibitors. Which can be overcome by the addition of more substrate?
Competitive inhibitors affect the active site of the enzyme. Noncompetitive inhibitors affect other parts of the enzyme. Competitive can be overcome by high substrate levels.
Imagine that the enzyme that breaks down cyclin is on strike and refuses to work. Explain what might be result from this situation.
Cyclin would remain and active MPF would be constantly present. This would signal the cell to continually divide.
Contrast and compare dendrites and axons.
Dendrites are nerve cell extensions that gather the nerve signal toward the cell body while Axons are long nerve cell extensions that carry the signal away from the cell body.
Describe how a nerve signal is transmitted down a typical neuron. Include the following in your description: hyperpolarization, depolarization, threshold, and refractory period.
Depolarization - a stimulus opens gates on Na+ channels allowing Na+ to move. Threshold - the voltage allowed by depolarization before a signal is sent Hyperpolarization - an increase in the magnitude of the membrane potential by opening K+ channels Refractory period - the time following an action potential before a second action potential can be sent.
Describe the gland and hormone dysfunction that causes Type II diabetes. Relate the symptoms of this condition to a regulation problem of the endocrine system. Describe how the disorder can be treated.
Dysfunction - deficiency of insulin and/or a change in the insulin receptors. Symptoms link - if the cells don't have or can't receive a cell communication signal for insulin, they don't increase the uptake of glucose. It becomes difficult to keep blood sugar levels from becoming too high. Treatment - diet, exercise, drugs and insulin shots (any two answers)
In the disease multiple sclerosis, myelin sheaths gradually harden and deteriorate. Discuss how this affects nervous system function.
Loss of the insulation provided by myelin sheaths leads to a disruption of the propagation of the nerve signal along the axons. The loss of signal is seen in loss of muscle control and coordination (or similar answer).
Some of the drugs classified as diuretics make the epithelium of the collecting duct less permeable to water. Discuss how this affects kidney function.
More water is lost as dilute urine and the kidney may have to compensate to save water
Contrast and compare exergonic reactions versus endergonic reactions. Which reaction type matches with catabolic reactions? Which matches with anabolic reactions?
Exergonic reactions release energy and match catabolic reactions. Endergonic reactions absorb or require energy and match anabolic reactions.
Identify and describe the four key functions of the excretory system.
Filtration - fluid collection through selectively permeable membranes Reabsorption - selective uptake of valuable solutes such as glucose, salts and amino acids Secretion - toxins and excessive ions are added to the contents of the excretory tubule Excretion - removal of the wastes from the body
Identify where in the cell cycle the three main checkpoints are located. What determines if the cell moves past each checkpoint?
G1 checkpoint - cell must receive a go-ahead signal or exit into Go G2 checkpoint - requires MPF activity to go-ahead to mitosis M checkpoint - controls the onset of anaphase.
During the light reaction the proton gradient across the thylakoid membrane can be as great as 3 pH units. On which side of the membrane (stroma or lumen of the grana) is the pH the lowest (which way are the H+ moving into)?
H+ are pumped into the space inside the grana raising the H+ concentration. This would result in the lowest pH.
Identify the four most common elements in living things. Give the most common valence for each element and explain the value of the valence in terms of the element's electron configuration.
Hydrogen - +1 - one outer shell or valence electron which is lost easily Carbon - + 4 or - 4 - four outer shell or valence electrons Oxygen - -2 - six outer shell electrons but tends to pull 2 more electrons in Nitrogen - -3 - five outer shell electrons, tends to pull 3 more electrons in 2.
Identify what types of molecules have difficulty crossing the plasma membrane and explain why.
Hydrophilic molecules - can't cross the hydrophobic fatty acids. Large molecules - too big. Ions - charges prevent crossing hydrophobic fatty acids
Give the following for each of the seven functional groups (can be done in a chart): a) Draw a structural diagram of the functional group ½ pt each b) Identify the name of the compounds that contain the functional group ½ pt each c) Describe the functional properties given to a carbon skeleton by the functional group ½ pt each
Hydroxyl - -OH, alcohols, hydrophilic Carbonyl - -C=O, ketones and aldehydes, hydrophilic Carboxyl - COOH, carboxylic acids and hydrophilic Sulfhydryl - -SH, thiols, protein structure and hydrophilic Amino - -NH2, amines, basic and hydrophilic Phosphates - PO4, phosphorylated molecule (or other acceptable name)- high energy and hydrophilic Methyl - -CH3, methylated (or other acceptable name), hydrophobic
Describe the feedback mechanisms that control blood calcium levels.
If high - thyroid releases calcitonin which stimulates uptake of Ca+2 by bones and reduces uptake in kidneys If low - Parathyroid glands release PTH which stimulates Ca+2 uptake by intestines, kidneys and release of Ca+2 release by bones.
How do the words innate and acquired relate to when these types of immunity develop in a human body?
Innate - present at birth before exposure to pathogen Acquired - defenses developed after birth and exposure to pathogens
Discuss why transferring a polar protein to a nonpolar solvent would likely cause it to denature.
It causes the nonpolar R groups to face outward, flipping the structure inside out
Discuss why Glycolysis is considered to be one of the first metabolic pathways to have evolved.
It is universal in all cells and most have come from a common ancestor.
Speculate on what the adaptive value is of having ATP synthase in the inner membrane instead of the outer membrane of the mitochondria.
It keeps the H+ ions near the ATP synthase. They would diffuse through the cytoplasm if it was in the outer membrane.
Explain why ATP can store so much energy.
It takes a great deal of energy to hold the three negatively charged phosphate groups together. They tend to repel each other.
In areas where the bedrock is granite (as in New England) acid precipitation is often a major problem. However, in areas where limestone is the bedrock (such as southern Indiana), acid precipitation is not usually a concern. Discuss why this might be so?
Limestone soils have calcium carbonate which serves as a buffer against the acid rain. Granite soils don't have a buffer against pH changes.
Discuss how nerve signaling is similar to the general events of "cell signaling" studied last semester.
Nerve signaling has the same three parts of reception, transduction and response or other similar answer.
Are both sides of a cell membrane the same? Explain and give evidence to support your answer.
No they are not the same because the two sides differ in phospholipid composition or the outer membrane has oligosaccharides attached while the inner membrane does not
If Science is a Process, discuss if the content and concepts you learn in AP Biology will stay the same for your entire adult career.
No, some will change over time because Science learns new things and makes changes in the body of knowledge.
Some students define Ps as the process by which plants use light energy as food. Discuss if this is a correct statement that would likely be accepted by an AP Biology Exam Reader.
No, this would not be an acceptable statement. Plants use light energy to make food such as carbohydrates. They do not "eat" light.
Is mitosis the same thing as Cytokinesis?
No. Mitosis is the division of the nucleus while cytokinesis is the division of the cytoplasm.
In thermodynamics, discuss what is the difference between an "open" system versus a "closed" system and which one best reflects living things.
Open systems obtain resources from outside themselves, closed systems can not. Life is an open system and must take energy from outside to offset entropy.
Describe how the bonding of Hydrogen and Oxygen result in a polar molecule and and Hydrogen bonds.
Oxygen holds the electrons more tightly than does Hydrogen, creating an unequal sharing of the electrons and charges. This results in charged areas in the water molecule. H bonds form between the positive Hydrogen area of one molecule to the negative area of another.
In the conversion of glucose and oxygen to carbon dioxide and water, which molecule is reduced? Explain how you know. Which molecule is oxidized? Explain how you know.
Oxygen is reduced. It gains electrons & energy½ pt - Glucose is oxidized. It loses electrons, energy and Hydrogens from Carbons
Contrast and compare passive and active transport. What kind of molecules are moved by each? Which direction do the materials move?
Passive transport does not require cell energy, active transport does. Passive transport works with non-polar and small molecules, water. Active transport works with polar molecules, ions and larger molecules. Passive is H->L, active is L-> H
Photorespiration costs the plant as much as 50% of the carbon fixed in the Calvin Cycle. Discuss why has this process not been selected against (or has it?).
Photorespiration represents an evolutionary relic when carbon dioxide levels were much higher. C4 (and CAM) Ps have been selected for in areas were photorespiration was high.
Discuss how the following relate to each other: presynaptic cell, postsynaptic cell, synapse, neurotransmitter.
Presynaptic cells carry the signal to a gap between two neurons called the synapse. The neurotransmitter is a chemical signal that crosses the gap to be received by the Postsynaptic cell.
Identify and describe the four levels of protein structure.
Primary - order of AA in the chain Secondary - H bonds between atoms of the backbone Tertiary - bonds or interactions between R groups Quaternary - interactions between several polypeptides to form a unit
Discuss why you would rather be hit by an object made of plant cells with primary cell walls than an object made of plant cells with secondary walls.
Primary cells. Primary cells have a soft cell wall; second cells have hard and thick cell walls such as found in wood. This would cause severe discomfort.
Identify and describe the three stages of cell signaling
Reception - receiving the signal Transduction - moving the signal through the membrane or intermediate molecules Response - how the signal is acted upon by the cell
Describe what is the "resting potential" of a typical nontransmitting neuron, what value does it have in mV, and how is it created and maintained?
Resting potential is the membrane potential of the neuron, at a value of 70mV, It is created by differences in ionic composition between intracellular and extracellular fluids, especially Na+ and K+, It is maintained by the Na+K+ pump
A typical prokaryotic cell has about 3000 genes in its DNA while a human cell has about 25,000 genes. About 1,000 of these genes are present in both types of cells. Based on your understanding of evolution, discuss how such different organisms could have this same subset of genes.
Same subset - suggests common origins from a shared ancestor. Shared genes - probably relate to shared characteristics of life such as the basic chemical functions, energy use, regulation, cell structure and order etc.
Describe what characteristics "Science" uses to investigate the universe that are unique from other ways of "knowing".
Science uses observations. Science uses experiments. Science assumes a cause and effect relationship between objects. Other acceptable response
Describe the basic pathway of information flow through neurons that cause you to turn your head when you hear the sound of your name being called.
Sensors in the ear transmit use sensory neurons to transmit the signal to the brain. Interneurons process the signal. Based on the processing, signals are sent to motor neurons to turn your head.
Contrast and compare sensory neurons, interneurons, and motor neurons
Sensory neurons or sensory receptors receive signals from the environment. Interneurons process the sensory input. Motor neurons carry the response from the interneurons to the muscles.
Describe how the adrenal gland is signaled by the hypothalamus and responds to short-term and long-term stress.
Short term - signal is from nervous system rather than hypothalamus. Epinephrine and norepinephrine are produced. Increased blood pressure, breathing rate, blood sugar, metabolic rate and changes in blood flow pattern Long term - hypothalamus releases ACTH which produces mineralocorticoids (increases water and sodium retention, increase blood volume and pressure) and glucocorticoids (produces more glucose, may suppress immune system)
Identify and describe three external defenses of the human body.
Skin - makes a physical barrier to microbes Mucous membranes - makes a physical barrier to microbes Gastric acid - kills bacteria with a low pH Lysozyme - an enzyme found in tears and saliva that attacks bacteria cell walls.
Cellulose and starch are both made of repeating units of glucose. Discuss what is different about their structure that gives them such different chemical properties and uses.
Starch is made of α glucose and cellulose is made of β glucose. They are isomers that differ in the position of the -OH on carbon 1.
Identify, define and give examples of the three major types of isomers.
Structural isomers - different arrangement of atoms Geometric isomers - different arrangement around a C=C Enantiomers - different arrangements on an asymmetrical carbon
From the "Transfomer" movies, are the Autobots and Decepticons "alive"? Explain and defend your answer.
The "machines" show all of the characteristics of life except having been made of cells. They have order and structure, they use energy, they respond to the environment, they have regulation, they can reproduce and show growth and development and the have the ability to adapt.
Describe how the nodes of Ranvier speed up transmission of a nerve signal.
The allow the signal to jump from node to node increasing the signal's speed.
Imagine another cell mutation that allows the cell to ignore anchorage dependency. Discuss what might be the results of this mutation.
The cells might divide and travel off. This is what happens when cancer undergoes metastasis and spreads through the body.
Explain the adaptive value for plants to have their leaves change color in the fall.
The chlorophyll is broken down and the N and Mg are saved for next year. This allows the plants to conserve rare elements and increase their efficiency.
During prometaphase, the nuclear envelope disappears. Where does it go?
The components of the nuclear envelope are in the cytoplasm.
A writer for a TV soap opera consults with you about their idea for killing off one of the characters. Their idea is to have the villain replace the IV drip being give to the character while they are unconscious in the hospital with a bag of distilled water. Could murder most foul be accomplished this way? Explain.
The distilled water is hypotonic to the cells and will cause them to swell and possible lyse. The destruction of the blood cells might lead to death.
Discuss why is the narrow area of electromagnetic radiation between 380-750 nm is the best choice to power a process like Ps.
The energy is strong enough to allow chemical bounds to be broken, but is not too strong to prevent bounds from forming at all (it's just right).
In the metabolic pathway, A->B->C->D->E, discuss what effect molecule E would likely have on regulating the enzyme that catalyzes the reaction of A to B?
The final product E is likely to have a feedback inhibition on the enzyme, shutting down the pathway when E is in excess.
The most accepted model of membrane structure today is the fluid mosaic model. Explain the meaning behind the terms "fluid" and "mosaic" in this model.
The fluid refers to the phospholipid bilayer. The molecules are not attached side to side and are free to slide next to each other and mosaic refers to the proteins in the phospholipid bilayer. The move continually and form changing patterns.
Imagine a cell that mutates and loses the function of its kinetochore proteins. Explain what this might do to the cell the next time it divides.
The kinetochores could not pull the replicated chromatids apart after the centromere breaks. The chromosomes would stay together and the chromosome number would likely double with each replication.
Discuss what determines whether a cell is a target cell for a particular signal molecule.
The most common method is if the cell has a receptor of that signal; or other acceptable answer.
The transmission of the nerve signal across a synapse uses concepts encountered in earlier parts of the course. Describe and explain how "diffusion", "receptors" and "cAMP" are involved at the synapse.
The neurotransmitters cross the gap by diffusion. The receptors receive the neurotransmitter on the postsynaptic membrane. cAMP is a secondary messenger in the transduction of the signal.
Contrast and compare the tasks or purposes of the Light Reaction and Dark Reaction.
The purpose of the light reaction is to capture light energy in to ATP and NADPH. The purpose of the dark reaction is to use ATP and NADPH to reduce carbon dioxide and make food.
In order for Dr. Smith's African violets to grow and flower, what photosynthesis to respiration ratio (Ps:Rs) must he create for them? Explain.
The ratio should Ps>Rs. Flowering costs the plant energy. The plant must have energy in surplus to afford to flower. The ratio that favors this is Ps>Rs where the plant is making more food than it is using. The surplus food can be used for making flowers.
Chemicals, such as colchicine from the Autumn Crocus plant, are known to disrupt spindle fibers. Speculate on what affect this will have on a cell undergoing mitosis. Identify what ploidy level (N=?) of the cell resulting from this treatment.
The spindle fibers will not form during mitosis and the chromatids cannot be pulled apart. This tends to double the chromosome number (tetraploid).
Explain why are mitochondria and chloroplasts not considered part of the endomembrane System.
They are not derived from the folding of cellular membranes (or similar answer)
Discuss what properties molecules that function as secondary messengers have in common.
They are small, hydrophilic and can diffuse rapidly.
Discuss what evidences exist that support the endosymbiotic theory that mitochondria and chloroplasts were once independent cells in their own right.
They have their own ribosomes which are the same size as prokaryotic ribosomes, They have circular DNA. They reproduce by binary fission
Explain how enzymes speed up chemical reactions in terms of changes in activation energy.
They lower the activation energy required for the reaction to take place.
Consider a liver cell (high metabolic rate) and a fat cell (low metabolic rate). Discuss how these two cells types will likely compare in terms of the number of mitochondria per cell and structure of their mitochondria.
They would have fewer mitochondria. They would have fewer cristae.
Describe what is a phosphorylation cascade
This is where one molecule activates several others, which in turn activate several new molecules, which in turn activate additional molecules. The signal can be amplified through the cascade
It is common to hear on many TV shows that someone has a "theory" about how a crime was committed and who was responsible. Discuss if this is a "Theory" or a "theory".
This statement would generally fit a "theory". It has not been tested repeatedly with the same result.
Explain why the energy investment phase of Glycolysis is necessary.
To make the glucose reactive
Identify which receptor mechanism is especially good for triggering several pathways at once. Explain how this mechanism can activate several different pathways.
Tyrosine kinase receptor, because multiple ATP and phosphorylations are involved, multiple transduction molecules can be activated in several pathways.
What is the adaptive value of fermentation? If given a choice, would a yeast cell "prefer" to conduct fermentation or cellular respiration? Explain.
Value - produce ATP in the absence of oxygen. Cellular Rs - produces 18x more ATP than fermentation
Locate an on-line animation or video about cells (besides the link given in the PowerPoints). Provide the following information for your on-line source:
a) address or link to the web site b) brief summary of what is covered by the web site c) describe something that impressed you about this web site (content, animation etc.). d) describe a constructive criticism you have about what is incorrect, misleading or could have been done better in this web site's presentation.
Predict what will happen if some of your cheek cells were placed in the following solutions?
a) hypertonic - cells shrink or crenate b) isotonic - cells stay the same c) hypotonic - cells swell and lyse
Predict what will happen to a cell with a rigid cell wall (e.g. bacteria or plant) if they a are placed in the following solutions?
a) hypertonic - cells shrink or plasmolysis occurs b) isotonic - cells are slightly flaccid c) hypotonic - cells are turgid or swollen
Describe the difference between active immunity and passive immunity.
activity immunity is when memory cells form in response to an infection passive immunity is from antibodies passed from mother to child and guard against microbes that the infant has not had.
Discuss what allergies are and describe how the body responds in an allergy reaction.
allergies are hypersensitivities to certain environmental antigens or allergens. Plasma cells secrete IgE specific for allergens. The IgE antibodies attach by their tails to mast cells. Reaction of the antibodies to the antigens causes the mast cells to release histamines and other inflammatory agents which cause dilation and increased permeability of small blood vessels. The inflammatory events lead to the typical allergy symptoms
What is an autoimmune disease? Give TWO examples and briefly describe the symptoms of each condition.
an autoimmune disease is when the immune system turns against the body lupus, rheumatoid arthritis, insulin-dependent diabetes mellitus, multiple sclerosis
Discuss why anaphylactic shock to an allergy is dangerous and sometimes fatal.
anaphylactic shock is a severe allergic reaction in which the abrupt dilation of peripheral blood vessels caused by widespread mast cell degranulation leads to a life-threatening drop in blood pressure.
Differentiate between an antigen and an antibody. What do these terms mean if a person is said to have blood type "A"?
antigen -a foreign molecule that elicits a specific response by lymphocytes antibody - a protein with two identical light polypeptide chains and two identical heavy chains which reacts with antigens. Blood type A has antigen A and anti-B antibody
Describe how a buffer works.
buffers can absorb or give up H+ ions keeping the pH constant
Discuss how you can tell the carbohydrates and fats apart just by looking at their formulas.
by the C:O ratio, which is 1:1 in carbohydrates and C>O in lipids
Discuss for an AP Biology exam reader several examples or reasons why apoptosis is necessary and even useful.
damaged cells need to be recycled, defective cells need to be destroyed before they become dangerous and spread (e.g. cancer), digits need to be spread apart etc.
Contrast and compare the structure of a fat, an oil and a phospholipid
fats have saturated fatty acids, oils have unsaturated fatty acids, and phospholipids have one of the three fatty acids replaced with a phosphate group.
Describe how are the three subphases of interphase are alike and how they are different.
hey are alike in that many of the cell's metabolic processes occur in all three. They are different by if the DNA has not replicated (G1), is replicating (S) or has already replicated (G2). The checkpoints are also different in each of phase.
Discuss why chaperon molecules are important to cells.
hey are large protein complexes that they help refold proteins into their proper shapes/functions
During periods of hot weather, the dew point (humidity level) is often linked to our level of comfort. Discuss why high dew points make us feel miserable.
high humidity prevents water from evaporating and cooling our bodies, which makes us feel hot and uncomfortable
Describe the differences between the humoral immune response and the cell-mediate immune response.
humoral immune response involves B cell activation and results from the production of antibodies that circulate in the blood plasma and lymph Cell-mediated immune response comes from T lymphocytes
Imagine that Dr. Smith has created a new kind of plant (Yes, he has done this frequently). Describe what criteria this plant must have to be a "success" in terms of Evolution by Natural Selection.
it must survive and it must reproduce
The mammalian kidney is thought to have been crucial in the success of these animals in terrestrial environments. Discuss the reasoning behind this statement.
kidneys allow the conservation of water by making highly concentrated urine
One of the first signs of cell death is that ions such as Na+ and K+ start moving down their concentration gradients. Explain why this is a good indicator that the cell is no longer viable.
movement down the concentration gradient indicates that active transport is no longer working. The cell may no longer be able to generate energy for active transport.
Describe the function of the following cells and chemicals of the innate immune system: neutrophils, monocytes, macrophages, natural killer (NK) cells, mast cells, histamine, interferons, complement system, prostaglandins and chemokines
neutrophils - short lived cells that phagocytose microbes monocytes - leukocytes that migrate from blood to tissues and develop into macrophages macrophages - large phagocytes that engulf microbes and dead tissue natural killer cells - leukocytes that attack membranes of infected or abnormal cells stimulating apoptosis. mast cells - cells that release histamine to initiate inflammatory response histamine - causes vasodilatation and increased permeability of blood vessels interferons - proteins released from viral infected cells that stimulate defenses of other cells complement system - set of serum proteins that cause lyses of microbes prostaglandins - released by macrophages and promote blood flow chemokines - chemical attractants that guide phagocyte migration
Contrast and compare an osmoconformer with an osmoregulator.
osmoconformer is isoosmotic with its surroundings and have no tendency to gain or lose water. All are marine. Osmoregulators controls its internal osmolarity independent of that of its environment. They gain or lose water and are freshwater or terrestrial.
Uncle Jack doesn't understand what all of the fuss is about with acid rain. After all, a change in pH from 6.0 to 5.0 is only 1, so how could it be harmful? Describe to Uncle Jack why this pH is actually a problem.
pH is a log scale and a change of 1 pH unit is a 10X change in H+ ions.
Compare the function of a protein kinase to a protein phosphatase. How are they similar and/or different?
protein kinase adds a Pi to a protein, protein phosphatase removes a Pi from a protein, they are antagonistic or opposites
Explain why most signals cannot cross the cell membrane and discuss the similarity between these reasons and why molecules need active transport mechanisms.
signal molecules are usually large and hydrophilic and can't cross membranes. Yes, the reasons are the same
Contrast and Compare the cell walls of plants and bacteria.
similar - both are external to the cell and offer support/protection different - they are made of different polysaccharides (or similar answer)
Describe how the 20 amino acids are similar, yet different in their structure.
similar because the have the H, amine group and carboxyl group on the carbon and they are different in the R group on the 4th bond.
Many living organisms have proteins that serve the same function, yet these proteins are often slightly different in their primary structure. Discuss how these proteins can have the same function, yet be different in their primary structure.
the R groups are in classes of properties. For example, a polar AA can replace another polar AA and give the same function, but the primary structure is now different.
When a cell becomes more ordered, one of the characteristics of life, what must happen in the rest of the universe? Which Law of Thermodynamics does this reflect?
the amount of Entropy increases. The second Law of Thermodynamics
A key process in metabolism is the transport of hydrogen ions (H+) across a membrane to create a concentration gradient. Other processes can result in an equal concentration of hydrogen ions on each side of a membrane. Explain which arrangement of hydrogen ions (unequal concentration or equal concentration) allows work to be done.
the arrangement where there is an unequal concentration of H+ ions allows work to be done. he difference in concentration gradient creates a free energy potential (and allows work)
The Na+/K+ pump, the major electrogenic pump in animal cells, exchanges sodium ions for potassium ions, both of which are cations. Describe how this exchange generates a membrane potential or difference in electrical charge since both ions have the same charge.
the cations are not in equal concentration giving one side a more positive charge as compared to the other.
A certain biological molecule has the ability to accept Hydrogen ions. Predict what will happen to the pH if this molecule is added to water.
the pH will increase or become more basic and fewer H+ ions are present which raises the pH value
The search for extraterrestrial life is often based on a search for water. Discuss why this is usually so?
the properties of water are conducive to life. If water is present, the chances of life being present is much higher.
Explain why integral proteins stay in place in the phospholipid bilayer.
the proteins have polar amino acids to match the head areas and non-polar amino acids in the fatty acid area
The structure of cilia and flagella are the same in all eukaryotic cells? Discuss why this might be so.
the structure must have originated very early in evolutionary history and has been inherited by all of the diverse types of eukaryotes.
1. Atoms can have various numbers associated with them: a) Define the following and show where each of them is placed relative to the symbol of an element such as Hydrogen (H): atomic number, atomic mass number b) Define what is mean by valence number c) Which of these structure numbers (atomic, mass or valence) is most related to the chemical behavior (function) of an atom?
these determine the type of bonds (and behaviors) between atoms
Lipids do not have a common chemical structure. Discuss why they are grouped together into a class of macromolecules.
they are all hydrophobic.
Speculate on why a change in pH or ion concentration such as Na+ would likely cause a protein to denature, especially through loss of secondary or tertiary structure.
they break the H bonds or ionic bonds in secondary and tertiary structure
Identify which function group monosaccharides have in the greatest abundance. Describe what properties this functional group gives monosaccharides.
they have multiple hydroxyl groups and the molecules are hydrophilic allowing sugars to dissolve in water easily.
In one episode of the original Star Trek series, the starship Enterprise was fighting a space-ship sized single-celled organism. In another episode, crew members were attacked by single cells the size of dinner plates. Discuss for the non-biologist why these episodes are clearly "science fiction".
they violate the cell surface area/volume ratio, cytoplasm to nucleus ratio problems, metabolic heat problems, other acceptable answer
Discuss how freezing of water can split rocks and create holes in pavement. water expands when it freezes, forcing the rocks to crack and break apart.
water expands when it freezes, forcing the rocks to crack and break apart.