AP Bio test
1. In a plant species, the purple flower allele is dominant over the yellow flower allele. A student crossed a purple plant with a yellow plant. Out of 146 offspring, 87 had purple flowers and 59 had yellow flowers. Calculate the Chi-squared value for the null hypothesis that the purple parent plant was heterozygous. Give your answer to the nearest tenth.
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Why would the beak size of the finches be likely to increase during this time?
Likely to increase because natural selection. Larger beaks break through tougher foods. Natural selection puts environmental pressure and selects for large beaks. Get food and then reproduce greater number of offspring and pass on genes for large beaks. Specific type of natural selection is directional.
What mechanism can explain the change in finch beak size. Explain fully.
Natural selection and individuals with biggest beak size survive and is passed on. Within population, according to hardy wine berg allele frequency is changing (Different forms of genes change, not in equilibrium).
24. HIV is a retrovirus. What is a retrovirus? Why might a virus that uses reverse transcriptase in its reproductive cycle be more prone to mutation?
Retrovirus: "any of a family of single-stranded RNA viruses having a helical envelope and containing an enzyme that allows for a reversal of genetic transcription, from RNA to DNA rather than the usual DNA to RNA, the newly transcribed viral DNA being incorporated into the host cell's DNA strand for the production of new RNA" A virus that uses reverse transcriptase in its reproductive cycle is more prone to mutation. The secondary structure of RNA template is an unrecognized factor that contributes to base misincorporation errors. **Retrovirus is an rna virus that inserts itself into dna. Special enzyme: reverse transcriptase (only exists in viruses). Gives it high rate of mutation/genetic variation because of no proofreading for reverse transciption- mistakes don't get caught and corrected (HIV). Makes vaccines impossible.
2. A population of frogs exists in which the allele for brown skin is dominant to the allele for green skin. In the area in which the frogs live, a drought kills much of the vegetation, causing the green frogs to be more visible to predators. At the end of the drought, 12% of the population has green skin. If the population is now in Hardy-Weinberg equilibrium, what will be the frequency of the green skin allele in the next generation? Show your answer to the nearest hundredth.
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47. Look at the diagram for # 46. Strenuous exercise lowers blood pH, causing the curves for both myoglobin and hemoglobin to move to the right. What would this shift result in?
02 dumped/loaded at lower pressures which is caused by hydrogen ions. Have different oxygen minding abilities because they have different abilities and locations.
How do eukaryotic cells use membranes?
1. Eukaryotic cells use membranes to regulate what goes in and out of the cells and for cell communication and signaling. Membranes=creation of gradients which are important for creation of abundance of ATP and increase energy production efficiency. Micro environments the inside tare created through organelles that allow for multitasking.
1. In a prairie community, the dominant prairie grass has been infected with a virus that disrupts one of the electron transport chains in the chloroplasts of the infected cells.
1. In a prairie community, the dominant prairie grass has been infected with a virus that disrupts one of the electron transport chains in the chloroplasts of the infected cells.
Innate immunity is non-specific and all people are born with it. If an innate immune cell engulfs a pathogen such as a bacterium, what organelle is going to function in breaking down that bacterium?
14. Succession is regrowth of species in area over time. Primary- no growth before, start from scratch. Created by volcanic explosions (islands), glaciers. Secondary- grows after wiped out after disaster (storm, fire, not starting from nothing). Secondary occurs faster. Pic is showing secondary session over years.
What is succession? Is this picture showing primary or secondary succession? Explain.
15. Bigger hardware trees main type because they are taller and most spaced out, can take in more nutrients. Decreased in numbers because harbor trees took nutrients and light and water from them. Relationship is basic competition.
In the use of a respirometer (we did this lab with germinating peas) what must be done to determine oxygen consumption if oxygen and carbon dioxide and used and produced at the same rate?
19. Scrubber holds CO2 produced in cotton ball.
a. Describe the most likely effects on cellular processes - be specific as to which processes and molecules are most likely to be directly involved.
1a. This virus would inhibit the efficiency of photosynthesis because the electron transport chain in chloroplasts is where the light-dependent reactions take place. In the light dependent reactions, sunlight strikes photosystem two and electrons are gained from this light energy. Electrons travel through the electron transport chain and pull H+ into the thylakoid space, creating an H+ gradient. These protons then diffuse through ATP synthase to create ATP. Electrons eventually reach photosystem one, and at the end electrons are accepted by NADP+ to create NADPH. If the electron transport chain is disrupted, then none of these processes can be carried out as efficiently. Electrons would not be able to travel through the electron transport chain properly and create an effective H+ gradient, and less ATP and NADPH would be made. Ultimately the light-dependent reactions would not be carried out properly in the chloroplasts.
b. Describe and explain the most likely effects on individual infected plants.
1b. An individual infected plant would not be able to carry out photosynthesis as efficiently. Because some of the chloroplasts in the plant would not be able to carry out the light dependent reactions, ATP and NADPH would not be created. As a result, the chloroplasts would not be able to carry out the Calvin cycle as ATP and NADPH drive the process. The plants would not be able to produce as much glucose overall from the Calvin cycle as it normally would and this would make cellular respiration less efficient as well. Cellular respiration relies on breaking down glucose to give the plant energy, and a lack of glucose would lead to a lack of energy for the plant. WIth a lack of energy, the plant would not be able to carry out all its bodily functions that it needs to do on a regular basis to grow and repair, and so infected plants could possibly die
c. Predict the short-term (within one year) effects on the infected plant populations and their communities. Support your prediction.
1c. The infected plant populations would decrease substantially within one year as they would not be able to survive with the inability to carry out photosynthesis and cellular respiration properly. This would affect the rest of the community as well, for other consumers rely on the prairie grass for food. With a decrease of the prairie grass, there would be more competition between herbivores for less resources, and the herbivores may decrease in population as there is less energy being transferred to the higher trophic levels. A decrease in primary consumers would lead to a decrease in secondary and tertiary consumers, as the secondary consumers eat the primary consumers and the tertiary consumers eat the secondary consumers.
d. Predict long-term effects (years to decades)on the infected plant populations and their communities. Support your prediction.
1d. Over many years, the infected plant populations would almost all die out. Consumers that normally rely on the grass as food would most likely change their eating habits and seek alternative food sources. This would cause other plants to lower in their population as new consumers are now eating them. This switch to new food sources may create competition for resources between different animals and may lead to a decrease in certain animal populations. Secondary and tertiary consumers that eat the primary consumers may be affected if the number of primary consumers decreases because they cannot find food. A decrease in primary consumers would lead to a decrease in secondary consumers that rely on the primary consumers and food, and a decrease in secondary consumers would lead to a decrease in tertiary consumers that rely on the secondary consumers as food. Also, animals that normally lived in the prairie grass would have to find new habitats. All of this would significantly affect the food web of the community. Over many years, the infected plant populations would almost all die out, but not all of the prairie grass would die out. Some of the prairie grass may develop a resistance to the virus through genetic mutations, and this would alter the allele frequencies in the population. The plants with the alleles for resistance would survive longer and reproduce more offspring with the resistance, and over time there the majority of individuals in the population would have the resistance. There might be some plants that are prone to the infection, but most of the infected plants or plants prone to the infection will die and their allele frequencies will decrease. The community would be stabilized as the prairie grass would adapt to a change in the environment through the process of natural selection, the mechanism that drives evolution.
2. In fruit flies, straight wings are dominant to wings that curl up. A certain population of flies is in Hardy-Weinberg equilibrium with respect to the alleles for wing shape. The equation is p2 + 2pq +q2
2. In fruit flies, straight wings are dominant to wings that curl up. A certain population of flies is in Hardy-Weinberg equilibrium with respect to the alleles for wing shape. The equation is p2 + 2pq +q2
Why would the oxygen consumption for the mice be lower at the higher temperature?
20. Lower at higher temperature because they are warm blooded so better able to control and regulate temp. 25 celcius
26. All organisms use a constant input of free energy. Different organisms use different metabolic strategies to get the energy they need for growth, reproduction, and homeostasis. How do plants and animals differ in their metabolic processes? What molecules do they use to store energy? Do animals use different molecules to store energy for long-term vs. short-term use?
26. Plants use photosynthesis (make glucose), cell respiration, autotrophs, and starches to store energy. Make glucose through carbohydrates. Animals are heterotrophs, Eat in order to do cell respiration. get glucose by breaking down food. Both have glucose to do cell respiration. cell respiration makes ATP. Extra glucose=stores as starch in (plants). Animals- dont use glucose, turns to glycogen, store extra as lipids in fat tissue aka adipose for long term and short term store in polymer of glucose, glycogen (liver,muscles).
How does exposure to light affect germination? Why were the stems longer in the dish 1 seedlings? What evidence supports genetic control of leaf color in the seedlings? If later observations showed that no yellow-leaf seedlings survived in either dish, what would be a likely explanation?
28. Exposure to light is necessary but not essential for germination (increases likelihood of germination), so the seeds in the in the covered environment (dish 1) grew longer stems to reach up to the light. Seeds didn't have light so they don't have PR. No light=grow upwards. Chlorophyll, which makes leaves green, only is made when there is light, which supports genetic evidence of leaf color in the seedlings (Dish 2 for genetic control because numbers dont change-light is not factor that controls that Genes are changing. Something internal changes rather than experimental. Yellow leafed plants don't survive because they don't have enough chlorophyll.
a. Explain what the terms in the equation represent in the population of fruit flies.
2a. p^2 represents the frequency of the homozygous straight-wing individuals. q^2 represents the frequency of the homozygous curly-wing individuals. 2pq represents the frequency of heterozygous straight-wing individuals. These individuals have one dominant allele for straight wings and one recessive allele for curly wings.
b. What are the conditions that are necessary for the population to be in equilibrium.
2b. The conditions that are necessary for the population to be in equilibrium include: large population size, no natural slection, no mutation, random mating, and no gene flow between different populations.
Organisms must exchange matter with their environment in order to grow, reproduce, and maintain life processes and organization. Why must cells, like simple epithelial cells, be small?
3. Cells like simple epithelial cells must be small because of the surface area must be bigger than volume ratio. Volume increases at a greater rate than surface area, so epithelial cells must remain small to have a greater surface area than volume. With a larger surface area, cells can exchange matter between the cell and the environment, enabling the organism to grow, reproduce, and maintain life processes and organization. Volume increases faster. Surface area of a cube (6xS^2). Volume of a cube (S^3).
3. Populations of different plant species have been found growing in mountain altitudes above 2,500 meters. The plant populations appear similar to, but have some differences with other plant populations found growing below 2,300 meters.
3. Populations of different plant species have been found growing in mountain altitudes above 2,500 meters. The plant populations appear similar to, but have some differences with other plant populations found growing below 2,300 meters.
30. What is the function of the endocrine system? Explain how both negative and positive feedback work in this system.
30. Endocrine system sends hormones and allows for communication all over the body. Positive feedback is when the reaction interferes and breaks homeostasis (oxytocin- during childbirth). Negative feedback maintains homeostasis (insulin and glucagon) Homeostasis (between normal range)
31. Five new bacteria species were discovered in Antarctic ice core samples. The following table shows the nucleotide base sequences of rRNA subunits.Draw a phylogenetic tree most consistent with the data.
31. phylogenetic tree - out group (not like the other, branched out alone)
32. Many medications interfere with pathways that cells use to respond to hormone signals. How can changes in signal transduction pathways alter cellular responses?
32. The signal may not get to the intended receiver so the action will not occur. Many steps in transduction which means easier for medication to denature or block an enzyme.
33. Drosophila is a common model organism in genetics. Two genes, bicoid and caudal, are needed for the embryos to properly develop. Examine the two graphs below: The diagrams show the levels of the two corresponding proteins along the anterior/posterior axis shortly after fertilization. What can you conclude about the importance of the two genes in embryo development?
33. The two importance of the two genes in embryo development are they help with the body's orientation and development. anterior - facing front posterior ( facing end) after fertilization bicoid goes down, caudal is near the bottom goes up. Biocoid, inhibits caudal production. Maintain high levels of bicoid, low caudal. one decreased the other increases.
34. Living cells can synthesize some of the amino acids needed to make proteins. However, some strains of E. coli can make tryptophan while others cannot. What is the most likely explanation of this genetic variation?
34. The most likely explanation of this genetic variation is mutation and selective pressure does not exist. As long as they can get it from their environment, they are not singled out.
35. Sickle cell anemia results from a point mutation in the hemoglobin gene. This causes a hydrophilic amino acid to be replaced with a hydrophobic amino acid in the hemoglobin protein. How would this change affect the protein?
35. The change affects the protein by changing the shape of it, may not denature. All proteins have 3/4 levels. first is determined by amino acid sequence. changes shape which changes function. sickle cells cant carry a lot of oxygen, actual shape makes it hard to clot, jam up. have circulation issues.
36. A population of beetles found on trees is changing due to pollution making the trees darker. Draw a graph of how the population would change as the pollution continues. What type of selection is this?
36. directional selection- a population is changing because trees change due to pollution-get darker. Darker color beetles survive and pass on that trait.
37. A population of mice lives in an area that has dark rocky places and light sandy places. The population has three morphs, light tan, white, and brown. The tan and brown individuals greatly outnumber the white mice. What type of selection is this? Draw a graph.
37. Disruptive selection- one form selected against.
46. The proteins myoglobin and hemoglobin bind to oxygen. Myoglobin is used by muscle cells and hemoglobin is used by red blood cells. The graph shows the binding at different concentrations of oxygen. Which molecule binds oxygen better at 3 kPa?
46. Myoglobin binds better. Hemoglobin is found in red blood cells and transports oxygen. Myoglobin-oxygen binding specific to muscles.
38. The humoral immune response occurs in people when they are exposed to specific pathogens, such as influenza B. This response causes the production of antibodies. The humoral response is slow upon first exposure and much quicker upon a second exposure to the same pathogen because of the creation of "memory cells" when the first exposure occurs. This graph shows the immune response upon two exposures to the same pathogen. Explain the graph.
38. The body had to figure out what to make and then remember it for the next time.Humoral response- causes antibody production. Creates memory cells. No antibody production=feel sick. Influenza B is destroyed and you feel good again. Wont get sick again because you have correct antibody right away. Vaccines get body to sensitize and prepare for a possible disease.
39. Students did an experiment on transformation in E.coli bacteria. They were trying to make the bacteria resistant to ampicillin. They used a plasmid with the ampr gene. In one sample the plasmid was added; in the other, it was not. The resulting growth is shown below. * Which plate/s have only ampicillin resistant bacteria? * Explain why there is no bacterial growth on plate 2. * Why were plates 1 and 3 included in the transformation experiment? * Why are there fewer colonies (represented by dots) on plate 4 than plate 3? * If a second experiment transformed the bacteria with a plasmid that had both genes for ampicillin resistance and human insulin, which plate would contain bacteria that could produce human insulin? Why?
39. Plate four has only ampicillin resistant bacteria because presence of anitcollen in media says if don't have it wont survive. There is no bacterial growth on plate two because there is no ampR gene. Plates one and three included in the transformation experiment to see group without the amp gene, served as controls, show viability of cultures. There are fewer colonies on plate 4 than plate 3 because in 3, never got 100% transformation. Plate four would contain bacteria that could produce human insulin because external marker would indicate that they took in gene, they're the only ones to survive.
a. Describe two kinds of data that could be collected to provide a direct answer to the question: Are the populations found above 2,500 meters and below 2,300 meters members of the same species?
3a. One way to find out if the two populations found above 2,500 meters and below 2,300 meters are members of the same sepcies is to breed two individuals together, one from each population, and see if they can produce viable, fertile offspring. Also, DNA can be compared to test if the two populations are part of the same species. When comparing DNA, you can compare the number of chromosomes using a karyotype as well as the structural components of the chromosomes.
b. Explain how the data you suggested in part a would answer the question posed.
3b. Breeding will give a direct answer to the question because if the two individuals can produce viable, fertile offspring whose offspring are also fertile, then the two populations are part of the same species. Comparing DNA will likewise give a direct answer because different species have a different number of chromosomes, so if the number of the chromosomes of the two individuals are the same, then the two populations are most likely part of the same species. Also, comparing the structural components, such as the genes of the chromosomes, can show similarities between the two populations. If individuals of the two species have the exact same genes, then the two individuals are part of the same species.
4. In eukaryotic cells, ribosomes can be found free in the cytoplasm or attached to the endoplasmic reticulum (ER). Proteins made by attached ribosomes are delivered to the ER while proteins made by free ribosomes are used in the cytosol. Briefly explain the following:
4. In eukaryotic cells, ribosomes can be found free in the cytoplasm or attached to the endoplasmic reticulum (ER). Proteins made by attached ribosomes are delivered to the ER while proteins made by free ribosomes are used in the cytosol. Briefly explain the following:
40. The energy transformation process of glycolysis is virtually the same in all three domains, archaea, bacteria, and eukarya. What hypothesis could you make based on this evidence?
40. Common ancestor or similar genetic codes contribute to the similarity in all three domains. Glycolosis= most ancient pathway because everything uses it and doesn't need oxygen/special organelles.
41. In the metamorphosis of a tadpole to a frog, the final stage involves the disappearance of the tail of the tadpole. What is a likely explanation for this disappearance?
41. The tail of the tadpole will most likely disappear because it is a fixation which no longer is useful once the tadpole becomes a frog. Tadpoles swim with their tail, but frogs swim with their legs, so the tail becomes unnecessary. Going from gills to lungs, tail to legs. Use program cell death and redistribute proteins from tail to make legs.
42. MRSA is a bacteria that is resistant to many antibiotics, including methicillin. The bacteria share the genes for methicillin resistance through horizontal gene transfer of plasmids. If a new medication was found that destroyed the MRSA bacteria, what would happen to the genes (the plasmids) for methicillin resistance over time?
42. The genes for methicillin resistance over time would increase because only the bacteria with those genes would be able to survive. Thus, that gene will be passed onto the offspring, which will make that gene more common. Decrease in gene but wont disappear- no selective pressure against.
44. The 4-cell stage of embryonic development of the tiny worm C.elegans is shown. The anterior daughter cell of cell 3 will give rise to muscle and reproductive tissue. The posterior daughter cell of cell 3 will give rise to the intestine as development progresses. However, if the 4 cells are separated from one another when the embryo is only 4 cells in total, no intestine will form in the worm. In further genetic studies, it was shown that if cells 3 and 4 are recombined, the intestine will develop normally. How can you explain this data?
44. Paracrine signaling has been used, which is when cells communicate to nearby cells. Cells orient themselves into a body plan, and they send short-range signals to communicate body plan. That is the only way the body can develop normally, because if the cells are separated, no communication can occur, and there will be no organs formed. **Cell to cell contact/signaling is found on membrane. Surface protein through direct contact causes cell 3 to start differentiation. 3—>AD, PD AD—>muscle reproductive tissue] experience cell differentiation PD—>intestines ] experience cell differentiation
45. In the northeast, the blue-eyed Mary flower is one of the first types of flowers to be seen in the spring. Though it is normally blue, pink and white varieties exist. Several breeding crosses of the flowers shown the following data:
45. This is Mendelian genetics. Epistatic allele causes blue color. at different locus, whole other gene controlling color.
48. Why do you think hemoglobin and myoglobin have different oxygen-binding abilities? Think about where these two oxygen-binding proteins are found.
48. Hemoglobin and myoglobin are essential for oxygen transport. They are good examples of form follows function. Myoglobin is responsible for the storage of oxygen, while hemoglobin is responsible for the transport of oxygen. Myoglobin is found in the muscle tissue, while hemoglobin is found in the blood, specifically in red blood cells. They have different oxygen-binding abilities because of their different structures and their location. Ligands bind independently to myoglobin, which means that the binding of a molecule has no influence on the binding of another in the presence of low partial pressure. More oxygen will bind when the partial pressure is higher. Myoglobin is less efficient at delivering oxygen and is rarely found outside the tissues. Hemoglobin and myoglobin work together for efficient transport of oxygen from the lungs to the tissues. High pressure in the lungs facilitates the binding of oxygen to hemoglobin, and then hemoglobin transports the oxygen to areas with lower pressure, such as the tissues. Oxygen then separates from hemoglobin and binds to myoglobin.
49. The chemical equation for photosynthesis is as follows: If the input water is labeled with heavy oxygen (18O), what else in the equation will also be labeled with heavy oxygen? Explain why this will happen.
49. If water is labeled with heavy oxygen, the oxygen on the other side of the photosynthesis equation will too. This happens because the oxygen in water is the source of the free oxygen in the air. Samuel Ruben and his colleagues at UC Berkeley showed this by testing the heavy oxygen input into carbon dioxide or water. They concluded that oxygen gas came from water. **Oxygen that is released comes from photolosys.
* One ultimate destination of a protein made by attached ribosomes and one general function of such a protein. (You do not have to name a specific protein)
4a. One ultimate destination of a protein by attached ribosomes may be out of the cell. This protein may be brought over to the golgi apparatus, where it is then refined and packaged for transport out of the cell. This protein may function in cell signaling by binding to the receptor of another cell on its plasma membrane to induce a signal transduction pathway and cause the cell to perform a certain activity.
XXXX* One ultimate destination of a protein produced on a free ribosome and one general function of the protein. (You do not have to name a specific protein)
4b. A protein produced on a free ribosome can go to the cytosol and serve as a structural protein that is part of the cytoskeleton. This protein in the cytosol can also function as an enzyme that breaks down organic compounds for the cell when needed.
What evidence supports the claim that all organisms share fundamental processes as a result of evolution?
5. DNA and RNA are found in all organisms. Found in archea, eukaraya, bacteria. Share common genetic code, excludes viruses. Sugar, phosphate, 4 nitrogen bases. DNA makes RNA. All have to do transcription which means they all do translation. Break MRNA into 3 bases (codon) which tells you what amino acid goes in what order in the sequence. Behind water, majority of living organisms are protein. Allows for DNA spicing to be possible. Code is universal. Through central dogma directing biotic ,anatomic, chemical, and physical characteristics.
50. Spirogyra, an autotrophic algae species, is grown in a lab in a water solution containing CO2 and phosphates, but not nitrogen-containing compounds. The lab workers determine the rate of synthesis of the four organic macromolecules. What are the four organic macromolecules? Which macromolecule/s will the alga have trouble producing and why?
50. The four organic macromolecules are lipids, proteins, carbohydrates, and nucleic acids. The algae will have trouble producing proteins and nucleic acids because they contain nitrogen. The algae is grown in an environment with a lack of nitrogen, so there will be a lack of the two macromolecules.
51. A person has an autoimmune disorder in which his immune system mistakenly makes antibodies to actelycholine receptors in neuromuscular junctions. Acetylcholine is a neurotransmitter than enables nerves and muscles to communicate. What would be a likely result if the antibodies are continually present? Why?
51. If these antibodies were continually present, then muscles will have a very hard time contracting when they need to. A person may not be able to walk properly, blink properly, or breath properly. This can also lead to a disorder called myasthenia gravis (MG). **Autoimmune disorder- response to self. Muscles wont function- fatigue, coordination problems.
52. In transduction of bacteria, say E.coli, for example, by a virus, the virus accidentally packages some of the host bacteria's DNA in with its own viral DNA. If the newly formed viruses then infect another E. coli cell, what will happen to the DNA of the new host cell?
52. The new host cell will have some of the old host cell's DNA inside of it through recombination. Scientists use this technique to introduce a foreign gene into a cell's genome. New bacteria virus infects will genetic recombo would happen, not good at making new viruses. New genetic code.
25. What would happen to a RBC in each type of solution: hypotonic, hypertonic, and isotonic solutions?
First blood cell is hypotonic-water going into cell (high to low concentration)-it could lyce/ rupture. Middle pic is isotonic (solute concentration is same outside and inside. no net gain or loss, stays balanced. ie red blood cells. last pic= Hypertonic
XXXX53. A researcher is growing algae in a flask of sterilized pond water. What will happen to the growth of the algae population if phosphate is added to the flask? Into which molecules will phosphate be incorporated? What would happen to the algae if only nitrogen was added to the flask instead of phosphate?
53. If phosphate was added, the rate of lipid synthesis would increase. This would benefit the cell membrane with its lipid bilayer and cholesterol. For nitrogen, protein synthesis and the creation of nucleic acids would increase. Similarities: Both chloroplasts and mitochondria generate ATP through the electron transport chain. The ETC is a proton pump that couples two reactions, one exergonic and one endergonic. It uses the energy released from the exergonic flow of electrons to pump protons against their concentration gradient . This results in the establishment of a proton gradient. Both chloroplasts and mitochondria use chemiosmosis with the enzyme ATP synthase to produce ATP. Protons diffuse down their concentration gradient through ATP synthase channels. As protons flow through the ATP-synthase channels, they generate energy to phosphorylate ADP into ATP. Differences: Mitochondria carry out cellular respiration, and ATP is the final product of cellular respiration, while chloroplasts carry out photosynthesis, and they generate ATP in the light-dependent reactions to power the Calvin Cycle, which is used to create organic compounds (glucose). In mitochondria, protons (H+) are pumped from the matrix to the intermembrane space and then they diffuse through ATP synthase back to the matrix. In chloroplasts, protons are pumped from the stroma to the thylakoid space and then they diffuse through ATP synthase back to the stroma.
53. A researcher is growing algae in a flask of sterilized pond water. What will happen to the growth of the algae population if phosphate is added to the flask? Into which molecules will phosphate be incorporated? What would happen to the algae if only nitrogen was added to the flask instead of phosphate?
53. If phosphate was added, the rate of lipid synthesis would increase. This would benefit the cell membrane with its lipid bilayer and cholesterol. For nitrogen, protein synthesis and the creation of nucleic acids would increase. **Phosphate is component of part of DNA and energy molecule ATP. Growth will increase with phosphate! Just adding nitrogen would stay the same growth wise because you are not increasing availability of extra energy. Phosphate is a limiting reactant.
54. Examine the diagrams that show how chloroplasts and mitochondria make ATP: What are the similarities and differences between the two mechanisms the organelles use to make ATP?
54. Similarities: Both chloroplasts and mitochondria generate ATP through the electron transport chain. The ETC is a proton pump that couples two reactions, one exergonic and one endergonic. It uses the energy released from the exergonic flow of electrons to pump protons against their concentration gradient . This results in the establishment of a proton gradient. Both chloroplasts and mitochondria use chemiosmosis with the enzyme ATP synthase to produce ATP. Protons diffuse down their concentration gradient through ATP synthase channels. As protons flow through the ATP-synthase channels, they generate energy to phosphorylate ADP into ATP. Differences: Mitochondria carry out cellular respiration, and ATP is the final product of cellular respiration, while chloroplasts carry out photosynthesis, and they generate ATP in the light-dependent reactions to power the Calvin Cycle, which is used to create organic compounds (glucose). In mitochondria, protons (H+) are pumped from the matrix to the intermembrane space and then they diffuse through ATP synthase back to the matrix. In chloroplasts, protons are pumped from the stroma to the thylakoid space and then they diffuse through ATP synthase back to the stroma. Source of hydrogen ions. Chloroplasts=water, Mitochondria=glucose (NADH).
Describe the process of DNA replication including the semi-conservative method, leading and lagging strands, Okazaki fragments, DNA polymerase, anti-parallel strand structure, and ligase.
6. (1) Helicase unwinds the parental double helix. (2) Single-strand binding proteins stabilize the unwound parental DNA. (3) The leading strand is synthesized continuously in the 5' → 3' direction by DNA polymerase. (4) The lagging strand is synthesized discontinuously. Primase synthesizes a short RNA primer, which is extended by DNA polymerase to form an Okazaki fragment. (5) After the RNA primer is replaced by another DNA polymerase, DNA ligase joins the Okazaki fragment to the growing strand. Only one can be copied continuously. Strands done at same time. Semi conservative method proposed by Watson and Crick and tested by Stahl and Melson. Semi conservative is good choice because not starting over so you conserve energy, has same code, few mistakes, easier and faster.
Why do you think the hardwood trees are the main type of tree in the mature forest? (Why did the pine trees decrease in number as time progressed?)
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What is the base-pairing rule? How many hydrogen bonds will form between each base pair? If strand "A"of DNA has 60% AT pairs and strand "B" has 45% AT base pairs, which strand will denature first upon heat exposure and why?
Adenine combines with thymine in equal amounts (have 2 between them) and cytosine and guanine (3 between them). Higher concentration of bonds is harder break. Innate immune cells- lysosomes break down using digestive enzymes by fusing with vacuole. Hydrolitic breaks down so membrane is non polar, prevents hydrolytic enzymes form eating through cell.
43. The human kidney is very efficient at filtering blood; it removes waste and recycles most water and nutrients back into circulation. Antidiuretic hormone (ADH) is secreted when there is a drop in blood plasma (the liquid portion of blood). This hormone stimulates the kidney cells to insert more aquaporins into their membranes. Aquaporins are proteins that assist in water movement across the plasma membrane. What would happen initially, if ADH release were to be prevented?
Aquaporins put into kidney cell membranes but if they are not, water cant go to kidney tubules to blood. Raises blood level. If this doesn't happen, person looses blood volume and gets worth.
How could you determine if the drought and resulting food change has had an impact on average beak size in the finch population?
Bigger beak, easier to eat. Chart beak sizes over period of time by looking at as many as you can (random sample) over at least drought period (91-98). Must be over spans of years.
Why would the oxygen consumption for the crickets be higher a the higher temperature?
Cricket is dependent on outside temp so slower at cold temperatures. Slower, colder it is.
What type of bond holds proteins (polypeptides) together? Describe how the bond is formed.
Dehydration reaction because squeezing out water molecule and new covalent bond is formed between carbon and nitrogen, it is also non polar (very strong and hard to break).
Does the diagram show the lac operon when lactose is present or absent? How do you know?
Diagram shows it not present because repressor is in the operan, holds lactose or repressor. If repressor is there, RNA polyermase cant remove.
If measurements of beak size from 1999 to 2006 show a decrease in average size, what is the likely cause?
Food source is changing and now there is no advantage for longer beak size so allele frequencies go back to what they were before drought.
Fish and mammals must both get rid of the toxic waste products of protein metabolism, nitrogenous wastes. Freshwater fish secrete ammonia directly into the water while mammals convert ammonia to urea, a less harmful form, before secretion with other wastes in urine. Why do you think freshwater fish do not convert ammonia to urea and eliminate it with concentrated urine like mammals?
If an organism has a sufficient supply of water, ammonia is directly secreted into the water. Freshwater fish do not convert ammonia to urea because it is already extremely diluted. 24. Retrovirus: "any of a family of single-stranded RNA viruses having a helical envelope and containing an enzyme that allows for a reversal of genetic transcription, from RNA to DNA rather than the usual DNA to RNA, the newly transcribed viral DNA being incorporated into the host cell's DNA strand for the production of new RNA" A virus that uses reverse transcriptase in its reproductive cycle is more prone to mutation. The secondary structure of RNA template is an unrecognized factor that contributes to base misincorporation errors. **On land you better have best conservation mechanisms possible (desert animals have long loop of henley so they don't pee and loose water)
What is the lac operon? What type of organism can have operons?
Operon is a mechanism to control gene expression (central dogma). Controls when it occurs. Prokaryote have one cells and need to store energy but cant- have to be super efficient and use operon to regulate what they make. Operon is composed of DNA. Not all operon is considered coding which makes proteins and other RNA. Some part of operon is regulatory (promoter- job is to bind RNA polymerase, operator- job is on/off switch).
What hypothesis did the Miller/Urey spark discharge apparatus support? Explain how.
Opran and Heldaine created hypothesis: organic compounds were building blocks of life. Present in early earth=lightening (energy/heat) methane and carbon dioxide, water, water vapor, sulfur dioxide. Gas missing was free oxygen. Four building blocks were present (CHON). Created environment that stimulated life on earth and found that amino acids formed (building blocks of proteins). Evidence of creation of organic compounds spontaneously.
If a protein (protein "XYZ") present in prokaryotes and plastids is similar to the eukaryotic protein tubulin in structure and function, what is the likely evolutionary significance of the relationship between the two proteins?
Plastids and prokaryotes have similar proteins as eukaryotic protein. Before prokaryotes and eukaryotes branched off, have tubulin but have similar proteins. Protein in common ancestor. Tubulin in eukaryotes were mutated over time and the protein was made different and more efficient.
What is the likely result of continued rainforest destruction?
Soil erosion, not going to create better farm lands because soil is nutrient poor due to heat and humidity, animal and plant species are lost (lost of biodiversity), decrease in exchange of oxygen and carbon dioxide. Take away organisms and carbon dioxide will increase. Positive feedback breaks homeostasis because more carbon dioxide in atmosphere higher the temperature. Tipping point in 2 degrees above normal.
In a certain habitat, developers will be reducing the primary producers by 50%. In the same habitat, deer and rabbits will be removed leaving only mice and voles as a food source for the two remaining predators, coyotes and hawks. What will happen to the two predators as a result of the development project?
Two predators compete for limited food sources and both have to adapt. Greater biomass=coyotees so they have greater need for energy. Optimal foraging limits energy to not use more than they get. Will have to change food sources or leave environment.
27. Contractile vacuoles are organelles that some protists, such as paramecia, use to maintain osmotic balance. Below is a graph that shows the functioning of the organelle as the paramecia are placed in salt solutions of increasing concentrations. What is an explanation of the data?
Water moves by osmosis- paramecia cant control water levels-what is coming in. Contractile vacuoles serve as pump to keep water out. Adding salt decreases water gradient. Get change in organelle. Graph looks like that because less water coming in, less work vacuole has to do. Isotonic=vacuole does nothing and osmotic balance is maintained.
29. Arctic foxes have a white coat in winter and a dark coat in the summer. What is a good explanation of the seasonal color change in the coat of the foxes?
seasonal camouflage to hide from predators, which allows them to survive longer and reproduce more offspring. Prey cant see you and predators cant see you. selective advantage from **produce more protein trigged by light exposure (outside stimulus), due to changing of gene expression. activates pigments
