Bio 1500 - All Exams
A drop of dye has been deposited at one end of a tank of water. In the figure below, shaded circles represent molecules of dye and open circles represent molecules of water. In which direction is the molecule labeled "1" (on the left 'high concentration' side) likely to move in the next instant of time? In which direction is the molecule labeled "3" (on the right 'low concentration' side) likely to move in the next instant of time?
- all directions are equally likely - all directions are equally likely
SARS-CoV-2 infects human cells by one of two methods:
- an endocytotic pathway - a receptor-based fusion
The synthesis of ATP in the mitochondria involves which of the following?
- diffusion of protons - consumption of glucose
The synthesis of ATP in the chloroplast involves which of the following?
- diffusion of protons - oxidation of water
Which of the following could have contributed to the evolution of dragonfly size over the history of their existence?
- presence of multiple alleles for genes encoding proteins involved in cellular respiration *- all of the four other answers could have contributed.* - independent evolution of enhanced bird flight - a misbalance in photosynthesis versus cellular respiration that favored photosynthesis - a rare mutation event
Which statement best describes the relationship between the terms 'gene' and 'allele.'
Alleles are specific versions of a gene
According to scientific evidence, which of the following statements best describes the history of life on Earth?
Although life began relatively soon after the Earth cooled, most major evolutionary changes occurred in the most recent quintile (=5th) of Earth's history.
(Solar Irradiance) Which of the following statements is a valid conclusion based on the data in the above figure?
Although solar irradiance and temperature used to be correlated, the recent increase in temperature cannot be explained by an increase in solar irradiance.
How does ATP synthase transfer the energy of the proton gradient into ATP?
As the protons pass through the ATP synthase they induce rotation which presses the ADP and Pi close together, so that they form a bond.
Chantelle is interested in whether there is an association between students' college majors and how much coffee they drink. She surveys the students, dividing them into humanities majors, social science majors, and STEM majors, and then plots the average number of cups of coffee consumed per week. Which of the following types of graph is Chantelle most likely to use to represent the data?
Bar graph
Why is the Myoglobin-O2 dissociation curve not sigmoidal in shape?
Because is consists only of a single globin unit with one heme
At an altitude higher than 6000m, humans cannot get sufficient oxygen into their body to do strenuous physical activity. The reason for this is:
Because the air pressure at this altitude is so low that the partial oxygen pressure is too low
Which of the following is a feature of birds that gives them increased respiratory efficiency compared with mammals?
Birds have very little residual volume in their respiratory system, so there isn't mixing of fresh and used air.
Two hummingbird species, one with a 'low altitude' Hb and one with a 'high altitude' Hb, are found living at ~2500 meters in the Andes and both forage on the same species of plant. Because of climate change this food plant's ecological range moves from ~2500 m to ~4000 m. What will happen to the two hummingbird species when this plant is found only at ~4000 m?
Both the 'low altitude' and 'high altitude' Hb-containing hummingbirds will follow the food plant up the mountain; the hummingbirds with the 'high altitude' Hb will continue to flourish, while the hummingbirds with the 'low altitude' Hb will likely struggle and potentially crash as a population.
A plant cell requires ATP to actively pump water up the stem. How does the cell obtain the ATP for this function?
By performing cellular respiration using glucose that was produced elsewhere in the plant
One strategy for treating Covid-19 might be to develop a drug that blocks the ACE2 receptors. How might such a drug benefit Covid patients?
By reducing the probability of the virus entering additional cells
Of the following questions, *?* would be classified as Bloom's Level Evaluate and *?* would be classified as Bloom's Level Apply? A. Make an animation that illustrates the process of viral reproduction. B. Explain how the coronavirus reproduces inside human cells. C. Should individual businesses be allowed to decide whether facemasks are required on their premises? D. Given what you have learned about how the Corona virus gains access to cells, describe a potential treatment that could block the virus from getting in. E. What is the name of the gene that codes for the Spike Proteins on the surface of the coronavirus? F. How do the 27 different proteins encoded by the viral genome interact to allow the virus to reproduce
C, D
Imagine that erosion begins to uncover large beds of coal that formed during the late Carboniferous (350 mya). These coal beds had been buried deep enough that they were not accessible to microorganisms. After erosion uncovers the coal, bacteria that have evolved over the last 100 million years can access the coal and break down its organic compounds to gain energy. Predict how this breakdown of coal will affect CO2 and O2 levels in the atmosphere.
CO2 level increases and O2 level decrease
What kind of organic molecule is a primary product of photosynthesis?
Carbohydrate
Image of chromosomes overlapping
Chromosomes are in the process of swapping pieces with each other.
White blood cells (e.g., T-cells, B-cells, macrophages) in the human body are all derived from the same stem cells, yet each of the differentiated white blood cell types has a different function. These different cell functions arise because:
Different genes are expressed in each cell type.
Which of the following is a constraint on the ability of living organisms to rely on diffusion to transport molecules?
Diffusion is only efficient over very short distances.
Cooperative binding of O2 to Hb refers to the:
Enhanced binding of O2 to Hb as more O2 molecules are bound
Which of the following is an important source of water in the Paramos ecosystem of the Andes?
Fog
Much of our coal was deposited during the Carboniferous. Why did coal formation stop?
Fungi evolved that can break down lignin, preventing the burial of carbon.
About 5 million years ago a mutation arose in the gene encoding the alpha1 subunit of hemoglobin in a bar-headed goose that resulted in the high altitude Hb. As discussed in class, this mutation converted an CCU codon in the mRNA (messenger RNA) into a GCU codon. What is the mutation that occurred in the DNA of the template strand that gave rise to the complementary mutant mRNA codon given above?
G to C
At the end of the light-independent reactions of photosynthesis, where is the energy from the sun located?
In the chemical bonds of glucose molecules
After a set of excited electrons has moved through the electron transport chain in cellular respiration, where is their energy located?
In the concentration gradient of protons
In a population of butterflies, the most common cause of death is being eaten by birds. Individual butterflies that have the ability to store toxins from plants survive better, because birds find these toxins distasteful. Over many generations, the average amount of toxins stored in the butterflies increases. Which of the following statements provides the best explanation for this change?
Individual butterflies that could store a lot of toxin survived better than those who couldn't store as much toxin.
The venom of some snakes acts by paralyzing muscles of mammals. If a sufficient amount of venom is injected into a mammal (or human), the mammal/human suffocates. Which step of the respiratory process in mammals does this venom most directly interfere with?
Inhalation of air into the lungs
How might the correction factor that is used when calculating the eGFR (estimated glomerular filtration rate) have a negative impact on Black patients with kidney disease?
It may over-estimate the health of the kidneys, preventing Black patients from qualifying for a kidney transplant.
How does oxygen move from the lungs into the blood?
It moves by diffusion from a region with a higher concentration of O2to a region with a lower concentration of O2.
Consider a population of Geese living at medium altitude (they are NOT migrating). Two forms of Hb occur in this population, the low-altitude Hb common in most lowland geese and a form of high altitude Hb. This population is forced by several years of very cold weather to move to a somewhat lower altitude. How will the abundance of the high altitude Hb allele change during these cold years and why?
It will decrease, because individuals with high altitude Hb will have lower fitness, as this Hb does not effectively release O2 in the body.
In a group of treefrogs in Missouri, some individuals produce high-pitched calls and other individuals produce low-pitched calls. You want to know whether the two calls indicate that there are two different species present, or whether these differences in calls are simply variation within a species. How could you tell?
Mate high-callers with low-callers, and see if the offspring can survive and reproduce.
A population of horned lizards lived for a long time in a valley without shrikes (=predators). Shrikes arrived and now lizards with longer horns were at an advantage. After a few years, the average horn length of the lizards had significantly increased. When did the mutations that lead to the longer horn length happen?
Most of them happened before the shrikes arrived
In Cellular respiration, the electron donor (i.e. the substance where the electron enters the ETC from] is *?* while in Photosynthesis, the electron donor is *?*.
NADH, H20
You talk with a friend from school about natural selection. Your friend states: "A random process like natural selection could never come up with such great features like our eyes!" Which statement would correct this misconception?
Natural selection is not random, as it is not arbitrary which individuals survive and reproduce and which ones not
In your community, a new virus has been introduced from Australia, which no one in the community has had contact with. The only available test for the infection with this virus determines whether antibodies exist in the blood of the person. Three days ago, you were in contact with a person infected with this new virus. Can you take the test today and get a reliable result?
No, because during the initial infections, antibodies are produced only after 4-6 days.
The myosin gene family consists of 18 different genes that code for different versions of myosin protein, which is involved in movement. Some versions of this protein are used in muscle contraction, others are used for transporting vesicles around cells or moving chloroplasts in response to light. Which of the following statements about the myosin genes is mostly likely true?
The 18 different genes arose as a result of gene duplication events
When you buy packaged meat in a supermarket, the cling wrap that covers the package allows O2 to pass through. What is the reason for this?
The O2 keeps the myoglobin in the oxygenated state, which gives the meat a bright red color.
Which of the following is a feature of the human respiratory system that arises from having a large residual lung volume?
The PO2 of the air in the lungs is lower than the PO2 of the atmosphere.
Which is the correct scientific definition of evolution?
The change of allele frequencies in a population over time
Which of the statements about dragonflies is true?
The four statements are all true.
A drop of dye has been deposited at one end of a tank of water. As expected, the dye will slowly but surely distribute in the tank through diffusion. You leave the tank of water alone for many hours and return to it later when the water has an even color across the tank, i.e. the dye is evenly distributed across the tank. Which statement best describes the behavior of individual dye molecules at the time you return?
The individual dye molecules are still moving in the same manner as when they were dropped into the tank.
When a muscle cell requires energy to perform its work of contraction, what happens to ATP?
The molecule loses a phosphate group.
In preparation for birth, a human fetus switches from producing fetal hemoglobin to producing adult hemoglobin. What would be a disadvantage of having only fetal hemoglobin once you are no longer inside your mother's womb?
The newborn's hemoglobin wouldn't release enough O2 to the active tissues.
What is the most random part of evolution?
The occurrence of changes in DNA is the most random event.
Which of the following must occur for two populations of the same species of monkey to evolve into two different species of monkey?
The populations must become genetically different from each other.
Although bats are considered the original source of most corona viruses that infect humans, the viruses typically pass through an intermediate host rather than moving directly from bats to humans. Why?
The spike proteins on the bat corona viruses don't fit any human receptors.
Evaluate this statement: 'If evidence supports a hypothesis, it is upgraded to a theory. If the theory gains even more evidence, it may be upgraded to a law.'
The statement is false because hypotheses, theories, and laws are all different things.
The placental mole and the marsupial mole are separate species that look very similar to each other: both have large 'hands' that are used for scooping dirt as they dig underground tunnels, both have very tiny eyes and a short tail, and both have fur that allows movement both forward and backward in tunnels. These two species are often cited as an example of convergent evolution. Given this information, which of the following is most likely true?
The two species of moles evolved these specialized traits independently of each other as a result of similar selection pressures.
Assume there is an acidic amino acid on the outside of one Hemoglobin subunit, interacting with a basic amino acid on another Hb subunit. If a mutation would replace this acidic amino acid with a basic amino acid, which statement below is most likely true?
The two subunits will move slightly apart and the affinity for oxygen will likely increase
Which of the following statements about COVID-19 vaccination is false?
The vaccine prevents SARS-CoV-2 infection.
Why did O2 concentrations in the atmosphere increase so dramatically during the Carboniferous?
There was an increase in the rate of PS relative to the rate of CR.
According to hiring managers of large companies, what is the most important characteristic of college graduates that they consider to hire?
They are well able to work with others and appreciate working in diverse groups.
Which of the following appropriately describe viruses?
They can have an RNA or DNA genome; they require a host for replication; they contain no organelles; they sometimes contain a lipid envelope
What is the role of memory cells in the immune system?
They respond quickly if you are re-infected with a pathogen that your body fought off in the past.
How does the human fetus obtain O2?
Through diffusion from mom's blood to fetal vessels in the placenta
What is the function of transcription during protein synthesis?
To copy the information in a gene
What was the main principle that your instructor applied when assigning you to teams?
To maximize the diversity of the teams as research shows that diverse teams are more successful
You have isolated and characterized a new virus and you want to know how to classify it among the known viruses. All of the following are appropriate questions to ask EXCEPT:
What symptoms does it cause when it infects a host?
A species of grasshoppers occurs in the central valley of California as well as on the surrounding mountains. Individuals living in the valley are significantly larger than individuals living on the mountains. Some researchers argue that this size difference is an adaptation (i.e. a trait that evolved by natural selection). Which of the following statements must be true if this body size difference is an evolved trait?
When mountain and valley individuals are raised in the same environment, mountain individuals still grow to a smaller size than valley individuals.
When a cell requires the production of a particular protein, a(n)*?* binds to the *?* of the gene, initiating transcription by *?* .
activator protein, promoter region, RNA polymerase
Look at the Hb-O2 dissociation curves shown below. If curve C represents Hb in the lungs, which curve represents Hb in active muscles?
active muscles is shifted to the right
Papain, which is a meat tenderizer, contains an enzyme that breaks down proteins. Suppose you put papain in a test tube with a sample of actin, which is a protein that is abundant in muscle (i.e. meat) tissue. When you examine the contents of the test tube later, what will you find?
amino acids
Mutations in genes can happen:
at any time
Although cellular respiration is advantageous for your muscle cells, why do they sometimes switch to lactic acid fermentation?
because sometimes there isn't enough oxygen for cellular respiration
Whereas the *?* structure of a protein is caused by interactions between the backbones of the amino acids, the *?* structure is caused by interactions between the R groups.
primary; tertiary
The ATP synthetase involved in generation of ATP from ADP and Pi is what kind of macromolecule?
protein
In birds, unlike mammals, the PO2 of the air in the lungs is *?* the outside air. This is because in birds, the residual volume of the respiratory system is *?* in mammals.
roughly the same; less than
Secondary/adaptive immunity is
slow, specific, highly effective
During glycolysis, a glucose molecule is split into:
two pyruvate molecules
Each of your instructors has at least one daughter with a lot of "pride" (=rainbow) things in their room. Among other things, one of the daughters has a rainbow light chain, with the different bulbs producing violet, blue, green, yellow, orange, and red light. How does the electromagnetic radiation from the various light bulbs differ? They differ in their:
wavelength
Which of the following is a potential factor for the higher mortality of black newborns compared to white newborns in the USA.
- Black women are "physiologically older" than white women of the same age, due to societal stresses - A higher percentage of black mothers have no access to affordable health insurance - Areas with majority black population have in average higher levels of pollution which results in poorer health. - Experiencing racism and socioeconomic disadvantage has negative impacts on health (e.g. chronically raised blood pressure
SARS-CoV-2 spike proteins are similar to hemoglobin in what way?
- Both represent targets for natural selection - Changes of single amino acids in both can have significant impacts on human physiology and health. - Mutations that 'open' the quaternary structures of both lead to increased binding of their preferred 'substrates.' - They are both multi-subunit proteins.
Blood acidosis, which results in a decrease of the blood's pH throughout the body, would have the following influences on the function of hemoglobin:
- To shift the Hb-O2 dissociation curve for the body 'to the right' - To shift the Hb-O2 dissociation curve in the lung 'to the right' - To decrease Hb affinity for O2 in the lung and the body - To decrease Hb affinity for O2 in the lung and decrease delivery of O2 to muscles
Which statement describes best the feeding habits of adult dragonflies?
Adult dragonflies hunt other flying insects while they are flying themselves; they cannot feed while walking or sitting.
Which statement best describes the insect respiratory system?
Air travels through tubes inside of the insect's body directly to the structures that need O2
Which one of the following variables influences the affinity of Hb for O2 in different parts of the body?
Temperature of the blood
In which sequence from oldest to youngest did these three events occur:first birds - first organisms with photosynthesis - snowball ice ages
oldest: photosynthesis middle: snowball ice age youngest: first birds
According to the article you read, all of the following gases contribute to the greenhouse effect EXCEPT
nitrogen
A mutation happens in the gene for a particular protein, leading to the substitution of one amino acid (AA) for another. Which of the following substitutions is most likely to result in a change in the function of the protein? Replacing ...
... a negatively charged AA with a positively charged AA
As new vaccines move through the clinical phases (e.g. phase I to phase II to phase III), ...
... more and more people are added to the vaccine trial as it moves through the phases.
Complete this sentence with the best option: Compared with at sea level, the partial pressure of O2 on Mt. Everest is ...
...lower, because there are fewer air molecules in total at high altitudes.
According to scientific evidence, approximately how long ago did life first arise on Earth?
3.8 billion years ago
Based on our exploration of Earth Viewer, which of the following statements best describes the history of Earth through deep time?
A. The Earth is highly dynamic, with large-scale changes in the amount of exposed land, the position of land masses, temperature, and concentrations of gases in the atmosphere.
When you shine white light on chlorophyll extract, the outside of the liquid turns red. Which statement describes best what happens?
Absorption of wavelength shorter than red light (e.g. blue or green light) moves electrons of the chlorophyll into a high energy state; when the electrons 'fall' back to a low energy state, they emit red light.
A plant cell has a defect that prevents it from producing sufficient amounts of chlorophyll. As a result, this cell is likely to suffer from a deficiency in:
Glucose
How do greenhouse gases raise the temperature of the atmosphere?
Greenhouse gases decrease the amount of heat energy that escapes from the earth's atmosphere.
You read about a new theory concerning the origin of the virus that causes Covid-19 and you want to determine whether or not the theory is scientific. All of the following are appropriate questions to ask EXCEPT:
Has the theory been proven to be true?
Based on what you learned in class, why do so many humans die when they climb Mt. Everest?
Hemoglobin can't pick up enough O2 in the lungs.
After reading the paper of Klok et al., a group of students wanted to test whether LOWER O2 levels would select for a smaller body size. They replicated the apparatus used by Klok et al. and put fruit flies for 8 generation in normal O2 levels (control) and low O2 levels of 15% (instead of 20%). They kept the flies for 8 generations in these conditions and then measured their body size. They found that the flies in the 15% O2 were about 20% smaller than the flies in the control conditions. They concluded that the flies under low O2 conditions evolved a smaller body size. Is this a valid conclusion?
No, because the students did not test whether a genetic change occurred. They needed to test both groups for a 9th generation under normal O2 levels to see whether the difference remained.
In Cellular respiration, the final electron acceptor of the ETC is *?* while in Photosynthesis the final acceptor is *?*
O2, NADP
Which of the following statements best describes the role of birds in influencing dragonfly size?
Once birds evolved, dragonflies were limited to smaller sizes, because small dragonflies are harder for birds to catch.
Think about the data analyzed in the Clapham and Karr paper: The comparison between the two data sets (i.e. oxygen levels and dragonfly size) illustrates that:
Oxygen levels are associated with dragonfly size in the first half of the time period represented, but not the second half.
About 5 million years ago a mutation arose in the gene encoding the alpha1 subunit of hemoglobin in a bar-headed goose that resulted in the high altitude Hb. As discussed in class, this mutation converted an CCU codon in the mRNA (messenger RNA) into a GCU codon. What, if any, amino acid change resulted from this mutation?
Pro to Ala
The oxygen revolution had both positive and negative implications for life on Earth. What was a disadvantage of the addition of oxygen to the atmosphere at the time it was initially produced?
Since oxygen is highly reactive, it damaged cells and caused a mass extinction of life.
One argument against vaccination that is often mentioned states that Covid vaccines may cause permanent infertility in women. What is the origin of this myth?
Some people are concerned that the immune system may attack the placenta after vaccination, since the attachment of placental cells to the uterus involves a protein that, although unrelated to SARS-CoV-2 spike protein, is known as a "spike protein."
When a plant cell produces glucose, the carbon atoms in the glucose molecule have come from *?* and the energy in the bonds of the glucose molecule has come from *?* .
carbon dioxide; sunlight
About 5 million years ago a mutation arose in the gene encoding the alpha1 subunit of hemoglobin in a bar-headed goose that resulted in the high altitude Hb. As discussed in class, this mutation converted an CCU codon in the mRNA (messenger RNA) into a GCU codon. What, if any, alteration in the function of the goose hemoglobin is likely to result from this mutation?
change from tense to relaxed quaternary structure, resulting in a left-shifted Hb-O2 dissociation curve
Primary/innate immune response is
fast, non-specific, not very effective
What does it mean if a channel in a cell membrane is selective?
the channel allows only certain substances to pass through, but not others
Which of the following topics from our course would be best classified at the ecological level?
the lack of aerial predators during the Carboniferous
In the diagram above, what is represented by the letter R?
the part of the molecule that differs among the amino acids
What is the primary function of the Electron Transport Chain in cellular respiration?
to establish a concentration gradient of protons
