Biology Exam 2
At an autosomal gene locus in humans, the allele for brown eyes is dominant over the allele for blue eyes. At another gene locus, located on the X chromosome, a recessive allele produces colorblindness while the dominant allele produces normal color vision. A heterozygous brown-eyed woman who is a carrier of colorblindness marries a blue-eyed man who is not colorblind. What is the probability that their first child will be a blue-eyed female who has normal color vision? (Enter the probability as a percent. Enter the number only without the percent sign. For example, enter 100% as 100 and enter 12.5% as 12.5)
25
In fruit flies () there is a dominant allele for red eyes and a recessive allele for white eyes. These alleles are located on the X chromosome. If a heterozygous red-eyed female is mated with a white-eyed male, what percentage of the offspring are expected to be white-eyed females? ( Enter the number only without the percent sign. For example, enter 100% as 100 and enter 12.5% as 12.5 )
25
How many tetrads are present in a single elephant cell (2n=56) during metaphase I of meiosis?
28
Let P = purple flowers and p = white, and T = tall plants and t = dwarf. Of the 16 possible gamete combinations in the dihybrid cross between 2 double heterozygotes, how many would produce the phenotype white, tall?
3
Starting with one molecule of acetyl CoA as an input, how many oxidation reactions occur during the Krebs cycle?
3
What time point represents G2?
3
In Mendel's experiments on seed color in pea plants, when a dominant yellow seed-bearing plant was crossed with a recessive green seed-bearing plant, what was the approximate phenotypic ratio among the F2 generation?
3 yellow: 1 green
In the light-independent reactions, when CO2 is added to a molecule of Ribulose 1,5-bisphosphate (RuBP) the immediate product is
3-phosphoglycerate.
A cell biologist examines a diploid cell from a particular species of during metaphase of mitosis and determines that 8 centromeres are present. Based on this finding, how many centromeres should be present in a single cell from this species during anaphase II of meiosis?
8
If there are 32 sister chromatids in a normal somatic cell, what is the haploid number for that cell?
8
The number of glyceraldehyde-3-phosphate molecules that would be produced from 24 turns of the Calvin cycle would be
8
The normal body temperature of a bat is similar to the normal body temperature of a human. Which of the curves below most likely represents an enzyme from a bat?
A
A particular reaction has a positive delta G. However, this reaction takes many years to proceed in the absence of enzyme. Why is this the case?
A certain amount of activation energy is required for the reaction to proceed.
A woman with blood type O has a child with blood type O. She claims that a man named Ralph is the child's father. Her claim would be proven false if Ralph has blood type: Check all that apply.
AB
When substrate-level phosphorylation occurs, it means that:
ADP is converted into ATP by the addition of a phosphate group.
What products of light reactions of photosynthesis are used in the Calvin cycle?
ATP and NADPH
How and where is ATP made in a eukaryotic cell?
ATP can be made by direct phosphorylation of ADP in the cytoplasm, and by an enzyme complex that uses the energy from a proton gradient to drive ATP synthesis in the mitochondria. It can also be made in other locations in the cell, depending on the cell type.
Why is the energy generated from the catabolism of sugars and other macromolecules ultimately harnessed to generate ATP?
ATP can be used by cells to drive endergonic reactions.
An organism acquires a mutation in the gene for pyruvate dehydrogenase that renders the protein unable to bind NADH. What is the most likely consequence of this mutation?
ATP synthesis will proceed at a high rate even when the cell has an ample supply.
Based on a variety of experiments, it is known that the rate of photosynthesis is highest when wavelengths of light between 400 and 500 nm are used, and when wavelengths around 700 nm are used. What can you infer about the relative importance of chlorophyll a and b in photosynthesis?
Absorption of light by chlorophyll a and b is essential for the process of photosynthesis
What molecule can oxidize NADH?
Acetaldehyde
Glucose is not our only food source, nor the only one we can utilize in our bodies to generate energy. Other primary sources of energy include other sugars, proteins, and fats. What metabolic intermediate are fats primarily converted into?
Acetyl-CoA
What important metabolic intermediate does not cross the inner membrane of the mitochondria?
Acetyl-CoA
If a germ-line cell from an owl contains 8 picograms of DNA during G1 of interphase, how many picograms of DNA would be present in each cell during prophase I of meiosis? (Enter the number only, not the units.)
16
If there are 32 sister chromatids in a normal somatic cell, how many chromosomes are there?
16
The genotypic ratio produced in the F2 generation is most likely
1:2:1.
The chloroplast is a membrane-bound organelle that is surrounded by an outer membrane. Aside from the outer membrane of the chloroplast, how many other types of membranes can be found inside the chloroplast?
2
What is the net number of ATP generated directly during glycolysis per molecule of glucose?
2
What are the products of one turn of the Krebs cycle?
2 CO2, 3 NADH, 1 FADH2, 1 ATP
Nondisjunction is the failure of homologous chromosomes to separate during meiosis I, or the failure of sister chromatids to separate during meiosis II or mitosis. As a result, both homologous chromosomes or both sister chromatids migrate to the same pole of the cell. This produces daughter cells with an imbalance of chromosomes. If 18 pairs of sister chromatids segregate normally during meiosis II in cats (n=19) but we have nondisjunction of 1 pair, then at the end of meiosis II we will have
2 cells with 19 chromosomes, 1 with 20, and 1 with 18.
Nondisjunction is the failure of homologous chromosomes to separate during meiosis I, or the failure of sister chromatids to separate during meiosis II or mitosis. As a result, both homologous chromosomes or both sister chromatids migrate to the same pole of the cell. This produces daughter cells with an imbalance of chromosomes. A cell biologist examines the final products of meiosis in an earthworm (2n=36) and finds 2 cells with 20 chromosomes, and 2 cells with 16 chromosomes. Most likely this was because
2 pairs of homologous chromosomes failed to separate during meiosis I.
. A cell biologist examines a diploid cell from a particular species of butterfly during prometaphase of mitosis and determines that 10 centromeres are present. Based on this finding, how many chromatids should be present in a single cell from this species in metaphase I of meiosis?
20
A cell biologist produces a karyotype of mouse somatic cells arrested at metaphase. She sees 40 chromosomes, which is completely normal for mice. Based on this information, what is the haploid number of chromosomes for mice?
20
If a somatic cell from a cat contains 40 picograms of DNA during G2 of interphase, how many picograms of DNA would be present in each cell during metaphase II of meiosis? (Enter the number only, not the units.)
20
If you take into account the amount of ATP generated by ATP synthase per molecule of NADH and per molecule of FADH2 produced, and the number of ATP molecules produced by substrate-level phosphorylation, what is the predicted energy yield of the Krebs cycle, per molecule of glucose in eukaryotic cells?
20 ATP
In humans, individuals with trisomy of which chromosome are most likely to survive until adulthood?
21st.
In animals that take in oxygen from their environment, glucose is broken down into carbon dioxide and water
Aerobic respiration
A human cell has a mutation in the gene that encodes the enzyme that generates lactate from pyruvate, rendering that enzyme completely non-functional. Assuming that there is ample glucose present, how would this cell generate energy in the presence of oxygen?
Aerobic respiration.
Knight followed up on attempts of English farmers to improve varieties of agriculture with his studies on garden peas. When he crossed two true-breeding varieties, he found all of the following: Check all that apply.
All the F1 offspring had the dominant trait. Some F2 offspring had the dominant trait and some had the recessive trait. Among the F2 offspring, more had the dominant trait and fewer had the recessive trait.
Based on his monohybrid crosses, Mendel's proposed which of the following? Check all that apply.
Alternative forms of a trait are encoded by alternative alleles. The 2 alleles for a given trait separate when gametes form. Each allele has an equal probability of being passed on to the gametes. Diploid individuals have 2 alleles for each trait.
Many of the antiviral drugs currently used to treat HIV/AIDS also interfere with an enzyme that helps mitochondria multiply. Treatment can therefore result in a decrease in the number of mitochondria found in certain tissues. Given this information, what might you expect to see in patients treated with antiviral drugs?
An increase in lactic acid levels
The stage of mitosis characterized by the physical separation of sister chromatids is called:
Anaphase
When do homologous chromosomes separate from each other during meiosis?
Anaphase I
Which structures indicate where crossing over has occurred.
Chiasmata
Seth purchased five pounds of live crayfish and realized that the outer shells were made of a tough carbohydrate similar to that used to make the carapace of a cockroach. What do you think the outer shells of the crawfish are made of?
Chitin
If you crossed flies heterozygous for the Cy allele, what phenotypes would you find in the adult F1 generation?
Both wild type and curly wings
The ATP generated from cellular respiration is not sufficient to drive the Calvin cycle in plants, even if appropriate levels of NADPH and CO2 are present. Why not?
Breaking down sugar to provide the energy needed to synthesize sugar would be a futile cycle.
AMP-activated protein kinase (AMPK) is an enzyme that is activated by high levels of AMP in cells. If levels of AMP are high in cells, that means that levels of ATP are low. Once active, AMPK activates catabolic pathways and inhibits anabolic pathways in the cell. Why do you think that is the case? Choose the answer that best explains the role of AMPK.
By activating catabolic pathways, AMPK provides a mechanism to activate exergonic pathways, which is important if AMP levels are high in the cell.
In G2, there are typically high levels of the mitotic cyclin. Why is cdc2 not active during G2 if the mitotic cyclin is present?
Cdc2 is also regulated by phosphorylation.
The equation for cellular respiration is: C6H12O6 + 6O2 6CO2 + 6H2O. At what specific point in the cellular respiration process has glucose been broken down completely from a six carbon molecule to 6 molecules of CO2?
During the second oxidation in the Krebs cycle
Within the human body, different cells have different characteristics or phenotypes. For example, neurons look and behave very differently from hepatocytes (liver cells). How can this be explained considering that all cells within a person were derived from the same starting cell?
Each cell type within a person must contain different proteins
Mendel performed reciprocal crosses in which he used pollen from a white-flowered plant to fertilize a purple-flowered plant and pollen from a purple-flowered plant to fertilize a white-flowered plant. What did these reciprocal crosses demonstrate?
Each parent made an equal genetic contribution to the offspring.
L-lysine is an essential amino acid and must be supplied in the diet. By comparison, the stereoisomer D-lysine is not biologically active. Why can your body only utilize one form?
Enzymes can only recognize a single, specific stereoisomer.
When oxygen is unavailable during heavy exercise what process do muscle cells use for energy generation?
Glycolysis coupled with lactate fermentation.
If citrate levels are high in the cell, but ATP levels are low, what do you think will happen in the cell?
Glycolysis will be inhibited, but the Krebs cycle will be functional, allowing it to be utilized to breakdown acetyl-CoA generated from beta-oxidation.
What color of light is not strongly absorbed by chlorophyll?
Green
In some species, sex determination is influenced by environmental temperature during development. If you wanted to determine the temperature at which one would obtain a 1:1 sex ratio in a particular species of turtle, which of the following experiments would best address this question?
Grow the turtles in five different incubators at temperatures of 22ºC, 24ºC, 26ºC, 28ºC, and 30ºC.
What type of cells contain only one set of chromosomes?
Haploid
Which cells never divide by meiosis? (Check all that apply.)
Haploid cells Somatic cells Zygotes
A person who has lost a large amount of blood but is still alive is found in a wrecked automobile under a highway bridge. Several people are helping the paramedics load the victim into the ambulance. After the ambulance has departed for the hospital, you overhear the following conversation from the persons who helped the paramedics. "I am certain that when that guy gets to the hospital, they will transfuse him with any blood that they have in the blood bank since he has lost so much blood." The other person says, "Yeah, I bet you're right!" Having had a biology course, you know which blood could be safely given to anyone. Select it below.
O
Light-dependent reactions generate
O2, ATP, and NADPH.
The aquatic plant Elodea is commonly used to study photosynthesis. You put some Elodea in a test tube filled with water containing radiolabeled oxygen (18O), shine light on the test tube, and measure the rate of photosynthesis by counting oxygen bubbles released. At the end of your experiment, you would find the most 18O in
O2.
Which of Mendel's Principles states that the two alleles present at each gene locus separate from one another during gamete formation and remain distinct?
Principle of Segregation
A cell biologist examines a skin cell from a lizard during metaphase of mitosis and determines that 20 chromatids are present. The role of meiosis in this species is to (Check all that apply)
Produce 4 daughter cells that are genetically different from each other. Produce 4 daughter cells that are genetically different from the original parental cell. Reduce the number of chromosomes per cell from 10 to 5.
A cell biologist examines a leaf cell from an alfalfa plant during metaphase of mitosis and determines that 32 chromatids are present. The role of fertilization in this species is to (Check all that apply)
Produce a new cell that has a combination of chromosomes from 2 different parents. Increase the number of chromosomes per cell from 8 to 16. Combine the chromosomes from 2 haploid cells into a single diploid cell.
During this stage of mitosis, the nuclear envelope begins to break down and the spindle begins to form.
Prophase
What immediately follows meiosis I?
Prophase II
The Law of Thermodynamics that states that increases in entropy are favored is the
Second Law of Thermodynamics.
What would you expect to happen if the anaphase-promoting complex/cyclosome (APC/C) failed to ubiquitinate securin?
The cohesin complex will persist, preventing the cell from entering anaphase.
If ATP synthase had a mutation in the F1 complex portion of the protein, what function of ATP synthase would most likely be affected?
The conversion of ADP and Pi to ATP.
Which best explains the process of meiosis?
The cells that result from meiosis I are haploid, and each chromosome consists of 2 chromatids.
The point of constriction on chromosomes that contains certain repeated DNA sequences that bind specific proteins is called
The centromere
phosphofructokinase is regulated by a number of factors, including high levels of ATP. Why is this enzyme regulated by ATP levels?
If ATP levels are high, it is important to directly inhibit the reaction that commits the substrate to glycolysis to allow the substrate to be available for other reactions, since the cell has ample energy.
Why is it so important that all of the chromosomes align on the metaphase plate during metaphase?
If they cannot, it suggests that they aren't properly attached to the spindle microtubules, and thus won't separate properly during anaphase.
In humans, the male has an X and a Y sex chromosome. The human female has two X chromosomes. In birds, the female has a Z and a W sex chromosome while the male has two Z chromosomes. Which of the following statements is accurate about which parent determines the gender of the offspring?
In humans, the male determines the gender of the offspring, and in birds the female determines the gender.
Where does pyruvate oxidation occur in eukaryotic cells?
In the mitochondria
While conducting an experiment, you realize that a competitive inhibitor was interfering with your reaction.
Increase the concentration of the correct substrate in the reaction.
What is the portion of the cell cycle during which the chromosomes are invisible under the light microscope because they are not yet condensed?
Interphase
The energy released in the mitochondrial electron transport chain is used to transport protons where?
Into the intermembrane space of the mitochondria
A ribozyme catalyzes a reaction on itself and actually changes shape. This is an example of what?
Intramolecular catalysis
You are working with a specific enzyme-catalyzed reaction in the lab. You are a very careful experimentalist, and as a result, at the beginning of each of your experiments, you measure the temperature in the lab. On days 1 through 5, the temperature in the lab was 20oC. Today is day 6 of your experiment, and the temperature in the lab is 30oC. How do you predict that this will alter the rate of your enzyme-catalyzed reaction?
It could possibly increase or decrease the rate.
In order to lose weight and reduce body fat, a friend of yours has decided to eliminate all fat from his diet, while consuming unrestricted amounts of carbohydrates. What do you think of this idea?
It is a bad idea, because if ATP levels are high in cells, excess acetyl-CoA from the metabolism of carbohydrates can be used for fatty acid synthesis.
What happens to the oxygen that is used in cellular respiration?
It is reduced to form water
Which statement about the P/O ratio is true?
It represents the amount of ATP produced by oxidative phosphorylation.
In a chemical reaction, glyceraldehyde-3-phosphate + NAD+ yields 1,3-bisphosphoglycerate + NADH. In this reaction, what happened to NAD+?
It was reduced to form NADH
If you were able to increase the kinetic energy of the molecules inside your body, how would this affect your body temperature?
It would increase.
What are the characteristics of red light, which is absorbed by chlorophylls?
Its photons have the longest wavelength in the visual spectrum
Yogurt contains galactose and glucose, which are generated when bacterial enzymes act on milk sugars. What is the main source of the galactose in yogurt?
Lactose
People who are lactose intolerant can often consume some products made from milk such as cheese and yogurt. By comparison, people with a true milk allergy, which involves an immune response to milk protein, cannot consume milk or products made from milk. Given this information, what can you conclude about milk?
Lactose is a carbohydrate, not a protein and is therefore not the cause of true milk allergies.
Carbon dioxide and water can combine to form glucose, water and oxygen. What is required for that process to occur?
Light energy from the sun
F. F. Blackman performed experiments to investigate the effects of various factors on photosynthesis. In one of his experiments, Blackman found that if light intensity was low that photosynthesis could be accelerated by increasing the amount of light, but not by increasing the temperature or carbon dioxide concentration. What can you conclude from this specific experiment?
Light is important for photosynthesis
The first detailed and quantitative studies on inheritance were carried out by an Austrian monk named _____.
Mendel
Why does sexual reproduction require both meiosis and syngamy?
The process of meiosis results in the production of gametes in which the number of chromosomes is reduced by half. During syngamy, two gametes fuse to form a new cell, and the number of chromosomes is restored to the full amount. Therefore, by coupling meiosis and syngamy, the organism ensures that the proper number of chromosomes will be maintained.
As electrons travel from the primary electron acceptor in photosystem II, down the electron transport chain to photosystem I, they drive the movement of protons from the stroma into the thylakoid compartment. Why is the development of this chemical gradient useful to photosynthesis?
The proton gradient can drive the production of ATP, which is needed for the light-independent reactions
A tomato plant is mutated with gamma radiation. A cellular analysis reveals that ATP synthase complexes found in the thylakoid membrane are inserted backwards into the membrane. What is the most likely outcome of this error?
The proton gradient in the thylakoid space will not be able to be used to generate ATP
Mendel demonstrated which of the following about inherited traits? Check all that apply.
Traits can be hidden in some generations, but subsequently reappear unchanged in future generations. Traits segregate among the offspring of a cross. Certain traits are more likely to appear than their alternatives. Parents that both have the same trait can have offspring with an alternative trait.
A person whose cells all contain a chromosome number of 2n+1 most likely has what type of condition?
Trisomy
A human female with only one X chromosome is said to have a condition called
Turner syndrome.
Kinases are enzymes that can phosphorylate (transfer phosphate groups onto) macromolecules such as proteins. A particular kinase, Kinase 1 is known to promote cell division. It promotes cell division by phosphorylating Protein X. Phosphorylation of Protein X activates Protein X. Once activated, Protein X stimulates the production of other proteins such as Protein Y and Z that directly promote cell division. In order to function, Kinase 1 requires the presence of Metal A. However, in the presence of Protein A, Kinase 1 is nonfunctional. From the description, what is considered a cofactor of Kinase 1?
Metal A
The drug Taxol, or Paclitaxel, is used to treat patients with a variety of cancers, including breast, lung and ovarian cancers. The drug works by stabilizing microtubules, and preventing their disassembly. The goal of the drug is to prevent dividing cells from being able to complete mitosis. As a result, cancerous cells can no longer divide. In a cell treated with Taxol, at what stage of mitosis will the cells arrest?
Metaphase
This is the stage of mitosis characterized by the alignment of the chromosomes in a ring along the inner circumference of the cell:
Metaphase
What process produces new cells that are genetically identical to the original cell?
Mitosis
The geneticist who discovered the white eye mutation in Drosophila and helped establish that genes are carried on chromosomes was
Morgan.
In later chapters, you will learn more about the regulation of gene expression. One way to regulate gene expression is to make changes to the histone proteins to alter how tightly the DNA is coiled and wrapped. The more tightly coiled and wrapped a particular region of DNA is, the less likely it is that the genes in that region will be expressed. Bearing this in mind, how tightly do you think regions of heterochromatin are compacted?
Very tightly
It is summer, and you are excited about going to your local amusement park, and specifically about riding the new roller coaster that was just built. You imagine waiting at the top of the stairs for the roller coaster to pull into the station, climbing into the car, strapping yourself into the seatbelt, and pulling down the harness. You can imagine the cars slowly chugging up to the top of the first hill, coming down on the other side, and the excitement you expect to feel as you go along for the ride. Of all of the things that you have imagined, which is an example of potential energy?
Waiting at the top of the stairs for the roller coaster to pull into the station
During meiosis, sister chromatids are held together by
a common centromere and a cohesin protein complex
In aerobic respiration, chemiosmotic generation of ATP is driven by:
a difference in H+ concentration on the two sides of the inner mitochondrial membrane.
a - glucose is present in potatoes and b - glucose is present in wood. Both are glucose molecules but one can be used by humans to synthesize ATP and one cannot. Based on this information, what is the best explanation on why humans can only digest one of the glucose types?
a- glucose and b - glucose are stereoisomers with OH groups oriented differently.
Carotenoids are important to many plants because these pigments are able to
absorb wavelengths of light that neither chlorophyll a nor b can absorb.
The energy needed to destabilize existing chemical bonds and start a chemical reaction is called
activation energy.
What is likely to occur if cyclin B were prevented from associating with its cyclin-dependent kinase near the end of meiosis I?
activation of DNA replication.
How does the organization of the bacterial genome differ from the organization of the eukaryotic genome
Most bacterial chromosomes are circular and the eukaryotic chromosomes contained in the nucleus are not.
Regardless of the electron or hydrogen acceptor used, one of the products of fermentation is always:
NAD
What is the oxidized form of the most common electron carrier that is needed for both glycolysis and the Krebs cycle?
NAD
What oxidizing agent is used to temporarily store high energy electrons harvested from glucose molecules in a series of gradual steps in the cytoplasm?
NAD
What is different about the way that NADH and FADH2 donate electrons to the electron transport chain?
NADH contributes its electrons to the first transmembrane complex in the electron transport chain and FADH2 contributes its electrons after the first transmembrane complex.
In plants, the light-dependent reactions require
NADP
Tacrolimus (FK-506) is a drug that inhibits an enzyme called calcineurin. Calcineurin is a protein phosphatase. This is an enzyme that dephosphorylates (removes phosphate groups from) proteins. When added to cells, tacrolimus can inhibit the dephosphorylation of a protein called NFAT, but it cannot prevent the dephosphorylation of a protein called CDK1. What is the most likely explanation for this finding?
NFAT is a substrate of calcineurin, but CDK1 is not.
The accommodation of the very long DNA strands that are part of a chromosome into the limited space of the nucleus is achieved by coiling the DNA around beads of histones into repeating subunits. These DNA-wrapped histones are called:
Nucleosomes
Mendel's Principle of Independent Assortment states that different pairs of
alleles segregate independently of each other.
Alternate forms of the same gene are called
alleles.
Chlorophyll b absorbs green wavelengths of light that chlorophyll a cannot absorb. In this respect, chlorophyll b acts as
an accessory pigment.
When the substrate is bound to the enzyme, the shape of the enzyme may change slightly, leading to
an induced fit.
Sister chromatids move to opposite poles of the cell during (Check all that apply.)
anaphase II of meiosis. anaphase of mitosis.
The aquatic plant Elodea is commonly used to study photosynthesis. You put some Elodea in a test tube, shine light on the plant, and count the bubbles that were released under varying conditions. Which results would you expect to see in your analysis of photosynthetic rate?
at high light intensities, the number of bubbles increase as carbon dioxide concentration increases
The term oxidation is derived from the name of the element oxygen. This is reasonable, because
attracts electrons very strongly.
Of the 23 pairs of human chromosomes, 22 pairs are homologous and are found in both males and females. These are called ________.
autosomes
Organisms that can manufacture their own chemical energy are called ____________.
autotrophs
Eukaryotic chromosomes are composed of a complex of 60% protein and 40% DNA. This complex is referred to as:
Chromatin
One way to generate acetyl-CoA is to convert pyruvate into acetyl-CoA by stripping off a C02 molecule. The removal of CO2 is referred to as what type of reaction?
Decarboxylation
You are studying an enzyme-catalyzed reaction that induces a particular cellular activity in the lab. If you wanted to slow down that particular cellular activity by controlling the enzyme, what could you do?
Decrease the temperature of the incubator where the cells are growing.
In the reaction: C4H6O4 + FAD C4H4O4 + FADH2, what type of reaction took place to remove the protons from C4H6O4?
Dehydrogenation
To form NADH from NAD+, two electrons and a proton are removed from an organic molecule. What term best describes the reaction in which electrons and a proton are removed from an organic molecule?
Dehydrogenation
A new antibiotic has been developed. It acts as a noncompetitive inhibitor. How will this antibiotic affect delta G for the enzyme-catalyzed reaction?
Delta G will be unaffected
Which experimental modifications would most effectively help to determine the sequence of reactions and the reaction intermediates in the Calvin cycle?
Exposing the cells to 14CO2 for various time intervals
Assuming no chromosomal aneuploidies, a calico cat would be which gender?
Female
The Law of Thermodynamics that states that energy cannot be created or destroyed is the
First Law of Thermodynamics
The portion of the cell cycle when the cell is growing and does not contain a replicated genome is referred to as:
G1
Interphase is made up of what stages of the cell cycle?
G1 + G2 + S
What is the sequence of events in a typical eukaryotic cell cycle?
G1 to S to G2 to mitosis to cytokinesis
At what checkpoint(s) does the cell arrest in response to DNA damage?
G1/S and G2/M
You are studying cell cycle progression in an early frog embryo. If you were to inject a protein synthesis inhibitor into a cell during S phase, where do you predict that the cells would arrest?
G2
As a result of the transition from daytime to nighttime, how will the relative concentrations of glyceraldehyde 3-phosphate (G3P) and ribulose 1,5-bisphosphate (RuBP) change in C3 plants?
G3P would increase and RuBP would decrease.
What type of animal cells are haploid?
Gametes.
During what step of glycolysis are two ATP molecules required?
Glucose priming
A bobcat is feeding on a white-tailed deer. It first eats the liver, which is rich in stored sugars. In what form would sugar be stored in the deer's liver?
Glycogen
This process is common to all living cells:
Glycolysis
What aspect of cellular respiration occurs in the cytoplasm in eukaryotic cells?
Glycolysis
What stage of cellular respiration can occur in human cells with or without oxygen present?
Glycolysis
At night, the Calvin cycle in a C3 plant
can still run as long as there is ATP, CO2, and NADPH present.
The role of the antenna complex in a photosystem is to
capture photons from sunlight.
Humans are unable to get metabolic energy from cellulose because:
cellulose digesting enzymes are absent from the human gut.
The point of connection between two sister chromatids, before anaphase II of meiosis separates them, is called the
centromere.
Fall leaf color on deciduous trees is a result of
cessation of chlorophyll production, which allows the accessory pigments to be revealed.
In an experiment described in a chemistry lab book, the directions state that after mixing two chemicals (A and B) and waiting 5 minutes that A will be oxidized. This means that
chemical A has lost electrons to chemical B.
In photosynthesis, ATP is made by
chemiosmosis.
Evidence of crossing over can often be seen under the light microscope as a structure called a _______.
chiasma
A modified form of cellulose found in the exoskeletons of insects and crustaceans is known as:
chitin
In eukaryotes, photosynthesis takes place inside ________.
chloroplasts
The organic non-protein components that aid in enzyme functioning are called
coenzymes.
The inorganic non-protein components that participate in enzyme catalysis are known as
cofactors.
In humans, if an XY individual had a deletion of the SRY gene, that person would
develop as a female.
A cross where we follow the inheritance of 2 pairs of alleles is called
dihybrid.
Individuals that have 2 alleles for most gene loci are best described as
diploid.
A secretor is a person who secretes their blood type antigens into body fluids such as saliva. By comparison, a non-secretor does not. A person's status as a secretor or non-secretor is independent of blood type. Consider the following inheritance pattern of this trait:
dominant.
As a genetic counselor, you are constructing a human pedigree for a particular disease. You note that every generation shows the trait, suggesting that the trait is
dominant.
During his experiments with pea plants, Mendel referred to the trait that was expressed in the F1 or first filial generation as
dominant.
In a heterozygous individual, the allele being expressed is
dominant.
In Drosophila, dosage compensation is controlled by the male-specific lethal (MSL) complex consisting of MSL proteins and roX RNAs. Based on what you know about dosage compensation, the role of the MSL complex in males would be to
double the level of expression of genes on the X chromosome.
Irene knows her blood type is A, but William does not know his blood type. However, William knows that his mother and father both had blood type B. Irene and William's first child is a boy with type O blood. Based on this information, William"s blood type could be
either B or O
Oxidation and reduction reactions are chemical processes that result in a gain or loss of
electrons
The synthesis of sugar molecules through the process of photosynthesis requires energy absorbed from sunlight. Bearing this in mind, what kind of reaction is photosynthesis?
endergonic
An extensive study was conducted on identical twins who were separated at birth. Among other things, the study showed that the individual from each pair who received better nutrition during childhood tended to score higher on standardized intelligence tests. This can best be described as an example of how
environment alters phenotype.
For a particular chemical reaction, the enthalpy of the reactants is -400 kJ. The enthalpy of the products is -390 kJ. The entropy of the reactants is 0.2 kJ/K. The entropy of the products is 0.3 kJ/K. The temperature of the reaction is 25oC. The likely conclusion you can draw from this reaction is it is
exergonic.
In 95% of cases of Down's syndrome, there is one extra chromosome (number 21) in every cell. This aneuploid condition is most likely the result of
failure of 1 homologous pair to segregate during meiosis.
If the gene encoding the enzyme rubisco is mutated such that it is non-functional, the process that would be affected is the ability to
fix carbon.
Your friend is having difficulty keeping track of the energy flow from glucose through glycolysis, the Krebs cycle and electron transport. Your best advice would be to:
follow the electrons.
Plant cells typically achieve cytokinesis by:
forming a cell plate across the middle of the cell.
Animal cells typically achieve cytokinesis by:
forming a cleavage furrow that pinches the cell into two.
A cell in G2 before meiosis begins, compared with one of the four cells produced at the end of meiosis II, has
four times as much DNA and twice as many chromosomes
The amount of energy available to do work is called
free energy
In modern terminology, Mendel's heredity "factors" are called
genes.
This term refers to the alleles that are present for a particular trait.
genotype
The allelic make up of a cell or individual is referred to as its
genotype.
In animals, the cells that will eventually undergo meiosis to produce gametes are set aside early in development. These are called
germ-line cells.
The most common form of gene therapy involves inserting a normal gene into cells that contain a defective version of the gene. In order to use gene therapy to prevent a man from passing a defective gene on to future generations, you should try to insert normal copies of the gene into
germ-line cells.
Dicyclohexylcarbodiimide (DCCD) is a chemical that disrupts the function of ATP synthase. Why will treatment with DCCD cause a cell to die?
protons cannot flow from the intermembrane space into the matrix
A calorie is the commonly used unit of chemical energy. It is also the unit of
heat
The classic experiments performed by Creighton and McClintock in Maize
provided evidence for the physical exchange of genetic material between homologues.
A diploid individual carrying two different alleles at a given gene locus is called
heterozygous.
If fertilization involves two gametes that contain different alleles of a given gene, the resulting offspring is
heterozygous.
Let P = purple flowers and p = white, and T = tall plants and t = dwarf. If the upper case letters represent the dominant alleles, what is the phenotype of a plant with the genotype PpTt?
purple flowers, tall
One of a pair of chromosomes with similar genetic information and from different sources like the sperm and egg.
homologue
A diploid individual carrying two identical alleles at a given gene locus is called
homozygous.
In photosynthesis, carbon fixation occurs:
in the Calvin cycle
Let R = red pigment and r = no pigment. In carnations, RR offspring make a lot of red pigment, rr offspring make no pigment and Rr offspring make a small amount of red pigment, thus appearing pink. Pink carnations are therefore an example of
incomplete dominance
Compared to asexual reproduction, the main advantage of sexual reproduction is that it
increases the genetic diversity of the offspring
The photosynthetic electron transport causes the accumulation of protons in which part of the chloroplast?
internal thylakoid space
In a chemical reaction, 1,3-bisphosphoglycerate + ADP yields 3-phosphoglycerate plus ATP. The delta G for this reaction is
less than zero
In Morgan's experiments, the white eye allele in Drosophila was shown to be
located on the X chromosome.
Glucose is broken down through cellular respiration, which involves a large number of chemical reactions. At the end of the cellular respiration process, a large number of ATP molecules are generated, yet not all of the possible energy that is contained in a molecule of glucose can be harnessed through these chemical reactions to generate ATP. In other words, during cellular respiration, not all of the energy that is contained in a molecule of glucose is converted into the energy stored in ATP. The remaining energy is
lost as heat.
In plants and animals, the zygote develops into an embryo by what process?
mitosis
Carbohydrates are composed of:
monosaccharides.
Carbohydrates are polymers formed of structural units called:
monosaccharides.
Humans who have lost one copy of an autosome are called
monosomic
During the light-dependent reactions, due to electron transport, the thylakoid space becomes
more acidic than the stroma.
ABO blood group determination is an example of
multiple alleles.
If a single gene has 3 or more alternative forms, this is called
multiple alleles.
The division of a bacterial cell occurs as the:
new membrane and cell wall materials begin to grow and form a septum.
Chitin, a modified form of cellulose, is not only cross-linked with proteins but its glucose units are modified with atoms of:
nitrogen
In his 1771 experiments, Joseph Priestly determined that plants added something to the air that allow an animal to survive. What do we now know that plants contribute to the air that is essential for animals (and other organisms)?
oxygen
The Calvin cycle requires all of the following except
oxygen
Mendel's understanding of the inheritance of traits in peas, expressed in modern language, included: Check all that apply.
parents transmit information encoded in genes each individual contains two genes for each trait not all genes are identical; alternative forms (alleles) exist each of the alleles present in an individual is discrete
The observable expression of the genes present in an organism is called its
phenotype
The observable expression of the genes present is called
phenotype.
The observable outward manifestation of the genes of an individual is referred to as its
phenotype.
Light consists of units of energy called
photons.
Clusters of chlorophyll and accessory pigments are called ________.
photosystems
Molecules that absorb light are called
pigments.
If an individual allele has more than one effect on the phenotype, this is called
pleiotropy.
A Punnett square is generally used to
predict the genotypic ratio among the offspring.
. Crossing over between homologous chromosomes takes place during
prophase I.
A scientist wants to study histones. Histones are:
proteins that double-stranded DNA molecules wrap around in eukaryotes.
An allele for a particular trait that is only expressed in the presence of a second copy of the same allele is called
recessive.
An allele that is present but unexpressed is
recessive.
When an atom or molecule gains one or more electrons, it is said to be
reduced
Genetic maps are based on recombination frequencies. Because both odd and even numbers of crossovers can occur between any 2 gene loci, as the physical distance between two loci increases, the maximum recombination frequency levels off at 50%. However, suppose you discovered a species where only an even number of crossovers can occur between any two gene loci. In this case, as the physical distance between two loci increases, you would expect the maximum recombination frequency to
remain at zero
In plants, production of NADPH
requires electrons originally found in water
RNA molecules that also act as enzymes are given the
ribozymes.
Traits that are controlled by genes located on the X chromosome are said to be ________________.
sex-linked
If a human female has 2 Barr bodies per cell, it is almost certain that
she developed from a fertilized egg with 3 X chromosomes.
If the Calvin cycle were to be temporarily restricted, the highest concentration of NADPH would likely be in the
stroma.
In an enzyme-catalyzed reaction, the reactant is called the
substrate.
What event occurs first during meiosis?
synapsis of homologous chromosomes
The pairing of chromosomes along their lengths, which is essential for crossing over, is referred to as
synapsis.
The pairing of homologous chromosomes is called
synapsis.
The fusion of a male gamete with a female gamete is called
syngamy.
In 1932, researchers Emerson and Arnold showed that the rate of photosynthesis saturated at a lower light intensity than expected for the number of individual chlorophyll molecules. From this observation they determined
that pigments were clustered in photosystems and they were measuring saturation of pigments in reaction centers
Energy is defined as
the capacity to do work
You are conducting a genetic screen using Caenorhabditis elegans embryos to isolate mutations affecting anaphase (A). Therefore, you need to look for embryos in which
the centromeres do not move toward the poles.
The independent assortment of allele pairs is due to
the independent segregation of homologous chromosome pairs during anaphase I.
In prophase, ribosomal RNA synthesis stops when the chromosomes condense, and as a result:
the nucleolus disappears.
In Drosophila, the sex of an individual is determined by
the number of X chromosomes.
A deletion of a particular stretch of chromosome 15 can cause either Prader-Willi syndrome or Angelman syndrome, depending on
the parental origin of the normal and deleted chromosome.
NADPH is made by
the passing of electrons from photosystem I to an electron transport chain
A photosystem channels the excitation energy gathered by absorption of light by any one of the pigment molecules to a specific reaction center chlorophyll, which in turn passes the energy to
the primary electron acceptor.
If the delta G of a reaction was -31.45 kJoules, you would know that
the reaction is spontaneous.
You return home to find that your baby brother has scattered his toy trains and trucks all over the floor of your room. As you begin to pick up the toys and put them away, you realize that even though he is just a baby, he has clearly mastered
the second law of thermodynamics.
The ultimate source of energy for humans comes from what source?
the sun
You are comparing the events of meiosis I in cells from several different organisms. You come across one species in which you do not observe any chiasmata. The best conclusion to make is
there is no crossing over between non-sister chromatids.
Fructose and galactose both have six carbon atoms, twelve hydrogen atoms and six oxygen atoms, just like glucose. A friend of yours says: "Since those sugars have the same number of atoms, they should have the same name." You answer: "While they do have the same number and type of atoms,
they are named differently because they are isomers of the monosaccharide, glucose."
You are working on a research project that involves a mutational analysis of the light harvesting complex Lhca1, which is an important light harvesting complex found in plants. Your labmate asks where this complex is located. You say it is in the
thylakoid membrane.
Flattened sacs of internal membranes associated with photosynthesis are called
thylakoids.
Diploid organisms use meiosis to produce haploid cells. Meiosis consists of how many rounds of nuclear division?
two
The zygote has
two copies of each chromosome.
The number of chromosomes characteristic of diploid eukaryotic cells, in general:
varies considerably from 2 to over 1000 in different species.
What is the color of light that chlorophylls absorb that has the highest energy?
violet-blue
For photosynthesis in green plants, the electron donor for the light dependent reaction is
water
Most atmospheric oxygen comes from photosynthesis. From which molecules is the oxygen derived?
water
Illuminated chloroplasts deprived of carbon dioxide
will accumulate ATP, NADPH, and not produce glucose
Edouard van Beneden proposed that an egg and a sperm, each containing half the complement of chromosomes found in somatic cells, fuse to produce a single cell called a(n) ______.
zygote
The cell produced by the fusion of an egg and a sperm is the
zygote.
In humans, if non-disjunction led to an individual with a genotype of XO, that person would
be female because each cell lacks a Y chromosome.
In humans, if non-disjunction led to an individual with a genotype of XXY, that person would
be male because each cell has one Y chromosome
In bacterial cell division, the cell divides into two nearly equal halves. This process is referred to as:
binary fission
When Mendel crossed purple-flowered pea plants with white-flowered pea plants, he never got offspring with flowers that had an intermediate color. This was counter to the theory of
blending inheritance.
Cardiac muscle cells need to generate significant amounts of ATP to allow for constant contractile activity. As a result, they primarily depend upon beta-oxidation of fatty acids, which has a higher energy yield than the catabolism of glucose. What would be the ATP yield for beta-oxidation of a hypothetical 10-carbon fatty acid?
62 ATP
Under standard conditions, ATP can release _______ for every molecule converted to ADP.
7.3 Kcal of energy
What is one of the roles of the APC/C during anaphase?
To directly target the mitotic cyclins for destruction.
Why are the components of the electron transport chain embedded in the inner mitochondrial membrane rather than floating freely in the cytoplasm of mitochondrial matrix?
To generate and maintain the proton gradient essential for ATP production.
Benedict's reagent is a chemical that is used as a test for the presence of a free aldehyde functional group on glucose. The aldehyde is used when glucose and fructose bind together to form sucrose, and the Benedict's test is negative. Starch contains a great deal of glucose but gives a negative Benedict's test because:
only the glucose at the end of a chain of starch will have an exposed aldehyde functional group to react with Benedict's reagent.
While standing at the top of the stairs, you have a potential energy of 40 Joules. If you walk all the way down the stairs, what would your potential energy be at the bottom of the stairs
0 Joules
How many Barr bodies does a normal human female contain in each diploid cell?
1
What events normally contribute to genetic variation?
. Fusion of a random egg and sperm to generate a zygote.
During this stage of mitosis, the chromosomes become attached to the spindle at their kinetochores.
. Prometaphase
Some organisms have a life cycle that is NOT an alternation between haploid and diploid stages. What is an example of an organism that has a life cycle that is NOT an alternation between diploid and haploid chromosome numbers?
. The bacterium E. coli
The synaptonemal complex is
. a network of proteins that holds homologues together
A somatic cell from a garden pea normally contains 14 chromosomes. How many sister chromatids would that cell contain during G1 of the cell cycle?
0
At an autosomal gene locus in humans, the allele for brown eyes is dominant over the allele for blue eyes. At another gene locus, located on the X chromosome, a recessive allele produces colorblindness while the dominant allele produces normal color vision. A heterozygous brown-eyed woman who is a carrier of colorblindness marries a blue-eyed man who is not colorblind. The woman becomes pregnant and an ultrasound test shows that the child is a girl. What is the probability that she will be colorblind? (Enter the probability as a percent. Enter the number only without the percent sign. For example, enter 100% as 100 and enter 12.5% as 12.5)
0
Meiosis results in a reassortment of maternal chromosomes (inherited from the mother) and paternal chromosomes (inherited from the father.) If n=4 for a given species, and ignoring the effects of crossing over, what is the probability that a gamete will receive only paternal chromosomes?
1/16
Let Y = yellow and y = green, and R = round and r = wrinkled. You cross YYRR peas with yyrr peas. All of the F1 individuals are yellow and round with a genotype of YyRr. You then perform an F2 cross and get the expected 9:3:3:1 phenotypic ratio. What proportion of the F2 plants are expected to be heterozygous for both traits?
1/4
In white tigers, the absence of fur pigmentation is caused by a recessive allele. This allele also causes the tigers to be cross-eyed. If two tigers heterozygous for this allele mate, what do you expect to see among the offspring?
1/4 will be both white and cross-eyed.
You are studying meiosis in an organism where 2n=24. How many chromosomes will each nucleus have after meiosis II is complete?
12
What would be the ATP yield for a molecule that is catabolized to form one molecule of pyruvate in a eukaryotic cell?
12.5 ATP
plant researcher wants to construct a synthetic cellulose fiber from 20 glucose molecules. How many molecules of CO2 and glyceraldehyde-3-phosphate are needed to construct the fiber?
120,40
You are studying meiosis in an organism where 2n= 28. How many chromosomes will be present in each cell after meiosis I is complete but before meiosis II begins?
14
In humans, red-green color blindness is caused by a recessive allele on the X chromosome. Therefore, if a female who is a carrier for the allele that causes color blindness marries a male who is color blind, the probability that their first child will be a girl who is color blind is 25%. This assumes normal dosage compensation where the X that is inactivated in females varies randomly from cell to cell. But suppose the normal mechanism of dosage compensation is altered so that the X that is inactivated in any given female is random but the same X is inactivated in every cell of her body. In this case, what is the probability that their first child would be a girl with color blindness? ( Express the probability as a percent. Enter the number only without the percent sign. For example, enter 100% as 100 and enter 12.5% as 12.5 )
37.5
A male fruit fly has the genotype PpYYrrTt. In terms of these 4 allele pairs, how many different types of gametes can he form?
4
A geneticist examines a somatic cell from a fly during metaphase of mitosis and determines that 16 chromatids are present. If a germ-line cell from this species divides by meiosis, then at the end of meiosis I (including the first cytokinesis) each cell will contain
4 chromosomes with 8 DNA molecules.
If there were no suppression of DNA replication between meiotic divisions but cytokinesis proceeded normally, what is the most likely outcome of meiosis?
4 diploid cells
A somatic cell from a corn plant normally contains 20 chromosomes. How many sister chromatids would that cell contain during G2 of the cell cycle?
40
Visible light has a wavelength range of:
400-740 nanometers.
If a germ-line cell from a salamander contains 10 picograms of DNA during G1 of interphase, how many picograms of DNA would be present in each gamete produced by this species? (Enter the number only, not the units.)
5
If you take into account the amount of ATP generated by ATP synthase per molecule of NADH produced in aerobic respiration, the net number of ATP molecules produced by substrate-level phosphorylation, and the fact that NADH molecules produced in the cytoplasm have to be transported into the mitochondria, what is the predicted energy yield of glycolysis in eukaryotic cells?
5 ATP
In mice, the allele for black fur is dominant to the allele for brown fur. If a male heterozygous black mouse is crossed with a female brown mouse, what percentage of the F1 offspring do you predict will be homozygous? ( Enter the number only without the percent sign. For example, enter 100% as 100 and enter 12.5% as 12.5 )
50
How many molecules of CO2 are needed to generate one molecule of glucose?
6
In order to generate one glucose molecule, the Calvin cycle has to turn how many times?
6
Starting with one molecule of glucose as an input, how many oxidation reactions occur during the Krebs cycle?
6
What is separase?
A protein that destroys cohesin through its protease activity.
What is the relationship between recombination frequency and the actual physical distance on a chromosome?
As physical distance increases, the recombination frequency first increases in a linear fashion, but gradually levels off to a frequency of 0.5.
Three babies were recently mixed up in a hospital. Based on the data in the table above, the couple with blood types B and O are the actual parents of the child with blood type
B
Most plants incorporate carbon dioxide into sugars by means of a cycle of reactions called the
Calvin Cycle
The cyclic carbon fixation reactions are also known as the
Calvin Cycle
Where do the carbon atoms in glucose come from?
Carbon dioxide
The progress of the eukaryotic cell cycle is regulated primarily by what proteins?
Cyclins
If a drug that inhibited transport from the trans face of the Golgi was applied to plant cells, which stage of the cell cycle would be directly affected?
Cytokinesis
The stage of the cell cycle during which the cytoplasm divides to form two cells is called:
Cytokinesis
Height is a trait that shows continuous variation in humans. In pea plants, on the other hand, the tall allele is dominant over the short allele and there are no intermediate heights. What is the best explanation for this difference?
Height is a polygenic trait in humans.
Organisms that depend on the energy stored in chemical bonds by other organisms for their food energy are called ____________.
Heterotrophs
Sometimes, when Mendel crossed two purple-flowered pea plants with each other, he obtained a phenotypic ratio of 3:1 (purple-flowered pea plants to white-flowered pea plants). These results are consistent with which of the following sets of parents?
Heterozygous purple pea plant and heterozygous purple pea plant
Why may eating carrots be useful for enhancing vision?
High levels of beta-carotene can lead to the production of a pigment used in vision.
The two copies of each type of chromosome found in normal somatic (body) cells in an organism, throughout the cell cycle, are called:
Homologous chromosomes
If it were possible to prevent crossing over, what would be the result of inhibiting this event?
Homologous chromosomes would not align properly during metaphase I
This term can be used to describe a diploid organism that has two identical alleles for a given trait.
Homozygous
During anaphase I, which best represents segregation of the chromatids that make up one pair of homologues? (M represents a maternal chromatid and P represents a paternal chromatid. Assume no crossing over occurs.)
M and M to one pole; P and P to the other pole.
Suppose you are carrying out a series of crosses with an insect where the mechanism of sex determination is unknown. You discover a mutant female with short bristles and decide to cross it with a wild type male that has normal bristles. Half of the F1 progeny have short bristles but all of these short-bristled F1 progeny are males. Based on these results, a valid hypothesis would be
Males are ZZ, females are ZW, and short bristles are caused by a dominant allele on the Z chromosome
In life cycles that alternate between haploid and diploid stages, fertilization doubles the number of chromosomes per cell while the number of chromosomes is reduced by half by which process?
Meiosis
The process of nuclear division which reduces the number of chromosomes per cell from 2 sets to 1 set, is called _____.
Meiosis
Many types of cancer cells have been detected to secrete significant levels of lactate. Do you think these cells are likely undergoing beta-oxidation?
No, because if lactate is being produced, the cell is not likely making use of the pathways needed to make use of the products of beta-oxidation.
You eat a bowl of beans as part of your dinner. As you digest the beans, the proteins that are present get broken down to their component amino acids. As your body destroys the macromolecules that were present in the beans, is the energy present in those molecules destroyed?
No. The energy contained within these macromolecules is converted into other forms of chemical energy and kinetic energy, though some is lost as heat.
In the photosystem I reaction center of green plants, light energy captured by pigment molecules is passed to a special reaction center chlorophyll a called
P700.
Let P = purple flowers and p = white, and T = tall plants and t = dwarf. What are the genotypes of the gametes that could be produced by a plant that is heterozygous for both traits?
PT, Pt, pT, and pt
Mendel used what plant for his studies on inheritance?
Pea
The splitting of water and the generation of oxygen occur where?
Photosystem II
In green plants, which photosystem absorbs photons to excite electrons in the reaction center?
Photosystems I and II
Jan Baptista van Helmont did an important experiment related to photosynthesis. He weighed a small willow tree and a pot of soil. Jan then planted the tree in the pot. Over the course of five years, he added only water to the pot. At the end of five years, he weighed the tree and found that it had gained 74.4 kg. He weighed the soil, and it was only 57 g less. What do the results of this specific experiment demonstrate about what is needed for a plant to grow and increase its mass?
Plants must be able to increase their mass using substances in addition to what is found in soil.
Kinases are enzymes that can phosphorylate (transfer phosphate groups onto) macromolecules such as proteins. A particular kinase, Kinase 1 is known to promote cell division. It promotes cell division by phosphorylating Protein X. Phosphorylation of Protein X activates Protein X. Once activated, Protein X stimulates the production of other proteins such as Protein Y and Z that directly promote cell division. In order to function, Kinase 1 requires the presence of Metal A. However, in the presence of Protein A, Kinase 1 is nonfunctional. From the description, what is considered the substrate of Kinase 1?
Protein X
In glycolysis, a major portion of the energy remains in the final product, which is called:
Pyruvate
What is an end-product of glycolysis?
Pyruvate
When amino acids are degraded in cells, into what intermediate(s) of the aerobic respiration process are the carbon skeletons of amino acids primarily converted?
Pyruvate and Krebs cycle intermediates
You are assembling a model of a chromosome, but begin having some trouble when you get to the step of forming chromatin loops. If you are unable to resolve this problem, what step of chromosome structure would you be unable to achieve?
Rosettes
In the light-independent reactions of photosynthesis, CO2 is added to a five-carbon molecule known as
RuBP
A duplicate copy of all of the hereditary information contained in the nucleus of eukaryotic cells is made during what stage of the cell cycle?
S
During what stages of the cell cycle are sister chromatids bound together by cohesin?
S, G2, prophase, metaphase
You decide to go on vacation in the mountains, where you are staying in a cabin. Unfortunately, when you turn on the water in the cabin you smell hydrogen sulfide (H2S) gas. After some research, you find out that the H2S may be due to the presence of sulfur bacteria living in your pipes. What molecule do these bacteria use as an electron acceptor?
SO4
If a cell contained a mutation in the gene that encodes FtsZ, what process would be affected?
Septation
Before cell division of somatic cells, each chromosome must be replicated. After replication, the resulting two parts of each chromosome are held together by cohesin at the centromere. These two parts are referred to as:
Sister chromatids
These structures are held together by cohesin:
Sister chromatids
In meiosis, sister kinetochores are attached to the same pole of the cell during meiosis I, and sister chromatid cohesion is released during anaphase II. What would be the likely result if sister kinetochores were attached to different poles of the cell during meiosis I and sister chromatid cohesion was released during anaphase I?
Sister chromatids would migrate to opposite poles during anaphase I.
In which part of the chloroplasts are the Calvin cycle enzymes located?
Stroma
Inside the chloroplast, where are organic molecules made?
Stroma
The theory of chromosomal inheritance was first proposed by
Sutton.
Which structure holds two homologous chromosomes together?
Synaptonemal complex
A biochemist wants to control the initial substrate-level phosphorylation that occurs in the tracheal cells of grasshoppers once glucose has crossed the plasma membrane. He has access to the following inhibitors: Rotenone - an electron transport chain inhibitor, Oligomycin - an ATP synthase inhibitor, and TLN-232, an inhibitor of glycolysis. Which inhibitor should he use to slow down initial substrate-level phosphorylation that occurs once glucose has crossed the plasma membrane?
TLN-232
This stage of mitosis is characterized by the disassembly of spindle apparatus, the reestablishment of the nuclear membrane, and the decondensation of the chromosomes:
Telophase
What stage of mitosis is essentially the reverse of prophase?
Telophase
If a chromosome contains a mutation such that it cannot bind to the kinetochore complex, what would be the consequence?
That chromosome would not be able to bind to the mitotic spindle.
You are examining the effect of maturation-promoting factor (MPF) in sea urchin cells, which have a diploid number of 36. If you fuse a dividing sea urchin cell with a G1 arrested oocyte, what would be the outcome?
The G1 cell would enter mitosis, but would likely arrest at the spindle checkpoint because the chromosomes have not been properly replicated.
You discover a new organism while on vacation in Yellowstone Park. You use a series of experiments to establish that it carries out aerobic respiration, but find that it has a unique ATP synthase that requires 16 protons per rotation. What does this tell you about the P/O ratio in this organism?
The P/O ratio in the new organism is lower than your P/O ratio
A new antibiotic has been developed that inhibits the activity of an enzyme by competitive inhibition. What effect will this have on the activation energy of the enzyme-catalyzed reaction?
The activation energy required for the reaction in the presence of the antibiotic will be the same as the activation energy required in the absence of the antibiotic.
Aerobic respiration is ultimately the reaction of glucose with oxygen to generate carbon dioxide, water, and energy. However, in a cell this process involves the transfer of electrons from glucose to carriers such as NAD+ over a lengthy series of steps. Why don't cells employ the direct reaction of glucose with oxygen to generate energy?
The direct transfer of electrons from glucose to oxygen occurs via a combustion reaction that is incompatible with life.
Cytochromes contain a heme group similar to that in hemoglobin. The iron atom (Fe) in the center of the group can be oxidized and reduced. If someone was suffering from iron deficiency anemia, what stage of cellular respiration would be most affected?
The electron transport chain
As electrons move along the electron transport chain, they lose potential energy. How is the energy that is released used by the cell?
The energy is used to transport protons against their concentration gradient
In order to reuse an enzyme after the conclusion of an enzyme catalyzed reaction, what must occur?
The enzyme has to separate itself from the product.
As a forensic pathologist, you have just completed an autopsy of a poisoning victim. After a thorough examination, you conclude that the victim died of cyanide poisoning. You know that cyanide binds to the cytochrome oxidase complex, and therefore list the official cause of death as suffocation due to cyanide exposure. However, if you wanted to provide a more technical explanation as to the cause of death, what process was specifically inhibited directly by cyanide?
The formation of water from oxygen
Consider the cell cycle of a human cell. During G2, what is the state of the homologous chromosomes?
The homologous chromosomes have all been copied through DNA replication and are beginning to condense
All of the reactions of cellular respiration that occur after glycolysis take place in what part of the eukaryotic cell?
The mitochondria
Based on the graph below, what are the optimal temperatures for the human enzyme and the hotsprings prokaryote enzyme?
The optimal temperature for the human enzyme is 40oC; the optimal temperature for the hotsprings prokaryote enzyme is 72oC.
Many metabolic pathways are ultimately concerned with ATP; either with the generation of ATP, or with the requirement of ATP for that pathway to function. Why is ATP so important to metabolism?
The phosphate groups of ATP are held together by unstable bonds that can be broken to release energy.
If chlorophyll a is blocked from absorbing light, what would be the effect on the ability of the plant to do photosynthesis?
The plant will have a decreased ability to carry out light-dependent reactions
A particular chemical reaction is exergonic. What can you say about the relationship between the reactants and the products in this exergonic reaction?
The reactants have more free energy than the products.
If a cell was capable of bypassing metaphase and going directly from prometaphase to anaphase, what is the most likely consequence of this?
The resulting daughter cells would have different numbers of chromosomes.
What happens during Anaphase B?
The spindle poles move apart
Before Mendel's experiments with pea plants, which ideas formed the basis for most thinking about heredity? Check all that apply.
The traits of both parents are blended together in their offspring Heredity occurs within species Traits are transmitted directly from parents to offspring
Which best describes the process of independent assortment?
The way one pair of homologues lines up along the metaphase plate does not affect how any other pair lines up.
If the antenna complex did not exist in a particular plant mesophyll cell, what effect would that have on photosynthesis?
These cells would have a reduced capacity to generate glucose
A current problem in modern medicine is the development of drug resistance mutations. This occurs when a mutation arises in a patient making him/her resistant to a drug and thus rendering the drug useless in treating a specific disease. Many useful drugs are competitive inhibitors of specific enzymes, and the drug-resistance mutations prevent the binding of the drug. These types of mutations, in addition to preventing competitive inhibitor binding, can also sometimes reduce the activity of the enzyme. Why is that the case?
These mutations most likely change the shape of the active site of the enzyme
What is common to all of the oxidation reactions in the Krebs cycle?
They are all characterized by a loss of electrons from an organic molecule coupled to the reduction of an electron acceptor.
What must happen to amino acids before they can be used in catabolic reactions?
They must be deaminated.
Why do we have storage macromolecules, such as fats, in our bodies?
We can break down these macromolecules to provide energy for the endergonic reactions in our bodies.
In 1910, Morgan did a series of experiments with the fruit fly Drosophila, an organism where females are XX and males are XY. When a mutant male fly with white eyes was crossed with a wild type female with red eyes, none of the F1 progeny had white eyes but 18% of the F2 progeny had white eyes. Unexpectedly, all of these white-eyed F2 flies were males. Based on these results, Morgan concluded that white eyes is caused by a recessive X-linked allele. Suppose Morgan has found that half of the F1 progeny had white eyes but all of these white-eyed F1 flies were females. In this case, a valid hypothesis would be
White eyes is caused by a dominant X-linked allele
If an XY human had a genetic disorder that causes insensitivity to androgens, that person's genotype and phenotype would be
XY, female.
In the absence of oxygen, can cells utilize the electron transport chain?
Yes, in the case that a cell can use a terminal electron acceptor other than oxygen, it can make use of the electron transport chain.
Does ADP contain the capacity to provide energy for the cell?
Yes. Cleaving the bond between the terminal phosphate and the phosphate attached to the ribose sugar can provide energy for the cell.
A molecule that closely resembles the shape of a substrate for an enzyme would most likely serve as a
competitive inhibitor
A drug binds to the active site of an enzyme. If it is bound to the active site of the enzyme, it prevents substrate binding. This drug would be considered a
competitive inhibitor.
Both photosystems I and II
contain a reaction center composed of chlorophyll a.
The light-independent reactions of photosynthesis are those that
convert CO2 into reduced molecules (sugars).
Homologous chromosomes pair along their length during prophase I of meiosis. While two homologues are paired, genetic exchange may occur between them in a process called ________.
crossing over
Chromosomes exchange genetic information by
crossing over.
The simplest and the most common monosaccharide is a six-carbon sugar called:
glucose.
Which of the following animals is a genetic male?
grasshopper XO
The Rec8 protein holds sister chromatids together during meiosis. If an individual has a mutation that prevents degradation of Rec8, this would most likely prevent
normal segregation during meiosis II.
At the end of meiosis II, each of the four resulting cells contains
one full set of chromosomes, each with 1 molecule of DNA.
