Biology Exam 3
The energy production per acetyl CoA molecule through the citric acid cycle is __________.
1 ATP, 3 NADH, 1 FADH2
A cell biologist carefully measured the quantity of DNA in grasshopper cells growing in cell culture. Cells examined during the G2 phase of the cell cycle contained 200 units of DNA. What would be the amount of DNA in one of the grasshopper daughter cells?
100 units
During glycolysis, a molecule of glucose is partially oxidized. What is the net gain of ATP and NADH for each glucose molecule during this chemical pathway?
2 ATP and 2 NADH
Mitosis and cytokinesis result in the formation of __________; meiosis and cytokinesis result in the formation of __________.
2 diploid; 4 haploid
At the end of telophase I of meiosis, as cytokinesis occurs, there are __________.
2 haploid cells
How many pairs of autosomes do humans have?
22
In humans, the haploid number of chromosomes is 23. Independent assortment has the possibility of producing __________ different gametes.
2^23
How many turns of the Calvin cycle are required to produce one G3P molecule?
3
In simple summary form, the input of the Calvin cycle for every product is __________, and the output is __________ used for glucose synthesis
3 CO2 ...; a three-carbon molecule
Substrate-level phosphorylation directly generates ATP during a chemical reaction. As a single molecule of glucose is completely oxidized in the presence of oxygen, what is the net yield of molecules of ATP made by substrate-level phosphorylation?
4 ATP
What is the typical result when a diploid cell undergoes meiosis?
4 haploid cells
A human somatic cell contains __________ chromosomes.
46
In a cell containing 10 chromosomes, meiosis results in the formation of daughter cells containing __________ chromosomes.
5
A human bone marrow cell in the prophase stage of mitosis contains 46 chromosomes. Therefore, there are a total of __________ sister chromatids in this cell.
92
In preparing pyruvate to enter the citric acid cycle, which of the following steps occurs?
A compound called coenzyme A binds to a two-carbon fragment
In cellular respiration, which of the following outcomes is the result of electrons moving through the electron transport chain (or its components)?
A proton gradient is formed.
In the first stage of cellular respiration (glycolysis), two molecules of pyruvate are produced. In the remaining stages of cellular respiration, a number of additional products are produced, such as __________. These other stages occur in the __________.
ATP ... mitochondria
Why is the citric acid cycle called a cycle?
Acetyl CoA binds to oxaloacetate that is restored at the end of the cycle.
What is the difference between a benign tumor and a malignant tumor?
Benign tumors do not metastasize; malignant tumors do
During meiosis I, homologous chromosomes form a tetrad and crossing over occurs. What is the outcome of crossing over?
Crossing over creates new combinations of genes present on a single chromosome
Which of the following statements regarding the reduction of CO2 to sugar during photosynthesis is true?
Electrons (with accompanying protons) are added to CO2 during photosynthesis
Which statement regarding the light reactions is true?
Electrons are supplied to chlorophyll P680 as it reduces the primary electron acceptor.
Which of the following best describes the electron transport chain?
Electrons pass from one carrier to another, releasing a little energy at each step.
Which of the following statements regarding aerobic cellular respiration is TRUE?
Glucose is completely oxidized to form carbon dioxide.
Which of the following statements regarding glycolysis is FALSE?
Glycolysis evolved in an oxygen-rich environment.
As photosynthesis occurs in chloroplasts, O2 is produced from _____ via a series of reactions associated with _____
H2O ... photosystem II
What is the main cause of the current amplification of global climate change?
Human activity is increasing the concentration of greenhouse gases, which delays the escape of heat from the planet.
What happens to the energy that is released by electrons as they move through the electron transport chain?
It pumps H+ through a membrane.
In the absence of oxygen, cells need a way to regenerate which compound?
NAD+
As shown below, an electron carrier, such as __________, acts as an energy-storage molecule when it is __________.
NADH ... reduced
During fermentation, __________ that was produced during glycolysis is converted back to __________.
NADH; NAD+
Oxygen is the final electron acceptor for cellular respiration. What is the final electron acceptor in the light reactions of photosynthesis?
NADP+
The light reactions of photosynthesis generate high-energy electrons, which end up in __________. The light reactions also produce __________ and __________.
NADPH : ATP : oxygen
The likelihood of death within twenty years of a diagnosis for DCIS (ductal carcinoma in situ, a type of breast cancer) is only 3.3%. Does this mean that every individual diagnosed with DCIS has a 3.3% chance of death within twenty years from the disease?
No. Individuals within certain risk groups (such as women under age 40) have a risk notably higher than 3.3%, whereas individuals not in these risk groups have a lower risk on average.
Consider the figure below. __________ is to a mitochondrion as __________ is to a chloroplast.
O2 ... CO2
Crossing over occurs during _____.
Prophase I
Synapsis occurs during _____.
Prophase I
Although the reactions of the Calvin cycle are not directly dependent on light, they usually do not occur at night. Why?
The Calvin cycle depends on products of the light reactions.
What is the purpose of embedding the electron transport chain in the membrane of a cell?
The electron acceptors can transport H+ across the membrane, which is otherwise impermeable to H+.
The M phase of mitosis and M phase of meiosis both occur after interphase. However, the two processes differ in the arrangement and behavior of their chromosomes. How?
The pairing up of homologous chromosomes and crossing over only occur during meiosis.
A red chemical dye known as phenol red changes to yellow when CO2 is present. A small green plant seedling is placed in phenol red and then placed in the dark. Which of the following is most likely to occur?
The solution is red to begin with, and it will turn yellow because respiration is occurring.
What is the ultimate fate of the electrons that are stripped from glucose during cellular respiration?
They are used to form water
Which of the following occurs during mitosis?
Two daughter nuclei, one at each pole of the cell, are generated.
Through respiration, humans breathe in O2 and breathe out CO2. However, what would happen if we did not breathe in O2?
We would not make enough ATP to meet our energy requirements
You have a large, healthy philodendron that you carelessly leave in total darkness while you are away on vacation. You are surprised to find that it is still alive when you return. What has the plant been using for an energy source while in the dark?
While it did have access to light before you left, the plant stored energy in the form of sugars or starch, and it was able to derive energy from those during your vacation
Which of the following represents a chromosomally normal human female?
XX
Which of the following is NOT a greenhouse gas?
all of the above
Crossing over is important because it __________.
allows the exchange of different versions of genes between homologous chromosomes
The stage of mitosis during which the chromosomes move toward separate poles of the cell is _____.
anaphase
In many organisms, including humans, chromosomes are found in homologous pairs. Homologous chromosomes _____.
are identical in the arrangement of their genes, but some versions of the genes may differ between the chromosomes
The Calvin cycle is a series of reactions that _____.
assemble sugar molecules by fixing carbon
A cell replicates its entire chromosomal DNA only __________.
before it is about to divide
Which of the following colors of light are useful during the process of photosynthesis?
blue, red, and violet
Considering the wavelengths of light shown below, the pigments in the granum absorb mainly in which range
blue-violet and red-orange
A small amount of ATP is made in glycolysis _____.
by the transfer of a phosphate group from a fragment of glucose to ADP (substrate-level phosphorylation)
Asexual and sexual reproduction differ in that sexual reproduction _____.
can produce great variation among the offspring
The most important role of pigments in photosynthesis is to _____.
capture light energy
In the Calvin cycle carbon dioxide provides _____, whereas ATP and NADPH provide _____ and _____, respectively.
carbon ... energy ... high-energy electrons
In an experiment, mice were fed glucose (C6H12O6) containing a small amount of radioactive carbon. The mice were closely monitored, and in a few minutes, radioactive carbon atoms showed up in __________.
carbon dioxide
Consider the photograph shown below. You can determine this is a plant cell rather than an animal cell because it has __________.
cell plate
A benign and a malignant tumor differ in that _____.
cells of a benign tumor remain within the tumor, whereas cells of a malignant tumor can spread to other body tissues
The O2 required for __________ is supplied by __________.
cellular respiration ... breathing
In the picture below, the chromosomal region where the nonsister chromatids are crossing over is called a(n) _____.
chiasma
Most NADH molecules generated during cellular respiration are produced during __________.
citric acid cycle
A single glucose molecule produces about 38 molecules of ATP through the process of cellular respiration. However, this only represents approximately 34% of the chemical energy present in this molecule. The rest of the energy from glucose is __________.
converted to heat
Meiosis differs from mitosis in that _____ only occurs in meiosis.
crossing over
A cleavage furrow forms in an animal cell during _____.
cytokinesis
Which of the following is the source of the energy that produces the chemiosmotic gradient in mitochondria?
electrons
The electron transport chain is, in essence, a series of redox reactions that conclude cellular respiration. During these redox reactions, __________.
electrons are transferred through a series of electron acceptors embedded within the inner mitochondrial membrane
The conversion of NADP+ to NADPH occurs with the assistance of __________.
electrons from water and energy from sunlight
Photosynthesis is an __________ process in which carbon is __________, whereas cellular respiration is an __________ process in which carbon is __________.
endergonic : reduced : exergonic : oxidized
The function of cellular respiration is to _____.
extract usable energy from glucose
The diploid phase of the human life cycle begins with _____.
fertilization
Cellular respiration completely breaks down a glucose molecule through glycolysis and the citric acid cycle. However, these two processes yield only a few ATPs. The majority of the energy the cell derives from glucose is _____.
found in NADH and FADH2
The function of meiosis is to make __________.
four cells with a haploid number of chromosomes
Each turn of the citric acid cycle generates one ATP and ___ additional energy-rich molecules: __________.
four; 3 NADH and 1 FADH2
The primary function of light absorption by photosystems I and II is to produce __________.
free, energized electrons
During asexual reproduction, yeast cells can produce _____.
genetically identical offspring
In the equation shown below, during cellular respiration __________ is oxidized and __________ is reduced
glucose ... oxygen
What is the name of the process in which glucose is converted to pyruvate?
glycolysis
Which stage of cellular respiration appears to have evolved first?
glycolysis
Which of the following colors is most strongly reflected by chlorophyll?
green
At the conclusion of meiosis I, the daughter cells are _____.
haploid and the sister chromatids are joined
Solar radiation warms the surface of the planet and then is radiated back in the form of __________.
heat
During anaphase I, __________.
homologous chromosomes move to opposite poles
A chemist has discovered a drug that blocks phosphoglucoisomerase, an enzyme that catalyzes the second reaction in glycolysis. He wants to use the drug to treat people with bacterial infections. However, he can't do this because _____.
human cells also perform glycolysis; the drug might also poison them
Chromatids are _____.
identical copies of each other if they are part of the same chromosome
Where does glycolysis occur in a eukaryotic cell?
in the cytoplasmic fluid
We inhale O2 and we exhale CO2. Carbon dioxide is produced __________.
in the reaction that creates acetyl CoA (coenzyme A) from pyruvate
Sports physiologists at an Olympic training center want to monitor athletes to determine at what point their muscles begin to function anaerobically. They could do this by checking for a buildup of _____.
lactic acid
In some organisms such as certain fungi and algae, cells undergo mitosis repeatedly without subsequently undergoing cytokinesis. What would be the consequence of this?
large cells containing many nuclei
The "photo-" part of the word photosynthesis refers to the _____, whereas "-synthesis" refers to _____.
light reactions that occur in the thylakoids : carbon fixation
In cellular respiration, glucose _____ electrons, whereas _____ electrons.
loses ... oxygen gains
A molecule is oxidized when it __________.
loses an electron
A molecule that functions as the electron donor in a redox reaction __________.
loses electrons and becomes oxidized
Primarily, cellular respiration serves to _____.
make ATP to power the cell's activities
Variation occurs when chromosomes are shuffled in _____.
meiosis
The electron transport chain is a series of electron carrier molecules. In eukaryotes, where can this structure be found?
mitochondria
A scientist wants to study the enzymes of the citric acid cycle in eukaryotic cells. What part of the cell would she use as a source of these enzymes?
mitochondrial matrix
After fertilization, the resulting zygote begins to divide by __________.
mitosis
Which of the following is NOT an aspect of global climate change?
net growth of polar ice caps
When we say that an organism is haploid, we mean that _____.
one set of chromosomes
During cell division, what role do centrosomes play?
organize microtubules
Cellular respiration and photosynthesis are similar in that both involve _____.
oxidation-reduction (redox) reactions
Some human cells, such as nerve cells, are restricted to aerobic respiration to recycle NADH and FADH2. If these cells are deprived of oxygen, then __________.
oxidative phosphorylation would come to a halt because there wouldn't be any oxygen to "pull" the electrons down the transport chain
The reaction center, antenna molecules, and primary electron acceptors that cluster in the thylakoid membrane form which structure?
photosystem
Bacteria have no membrane-enclosed organelles. However, some still generate ATP through cellular respiration. Where might the electron transport chain be found in these organisms?
plasma membrane
Asexual reproduction _____.
process of reproduction involving a single parent that results in offspring that are genetically identical to the parent
In the telophase of mitosis, the mitotic spindle breaks down and the chromatin uncoils. This is essentially the opposite of what happens in _____.
prophase
Which of the following shows mitosis in the correct chronological order?
prophase, prometaphase, metaphase, anaphase, telophase
In oxidative phosphorylation, electrons are passed from one electron carrier to another. The energy released is used to __________.
pump protons (H+) across the mitochondrial membrane
A muscle cell deprived of molecular oxygen will convert glucose to lactic acid to __________.
recycle NADH through fermentation
One version of a gene may encode __________, whereas a different version of the same gene may encode __________.
red eyes, white eyes
In eukaryotes, most of the high-energy electrons released from glucose by cellular respiration __________.
reduce NAD+ to NADH, which then delivers them to the electron transport chain
The light reactions of photosynthesis involve __________.
reduction of NADP+
Glycolysis is the only stage of cellular respiration that __________.
requires ATP to make ATP
In meiosis II, _____.
sister chromatids separate
During anaphase II, __________.
sister chromatids separate and migrate toward opposite poles
The kinetochores are __________.
sites at which microtubules attach to chromosomes
An example of a cell that is 2n is a __________.
somatic cells
Carbon dioxide enters a leaf through the _____.
stomata
The photosynthetic event known as the Calvin cycle occurs in the __________.
stroma
Which of the following is a key difference between meiosis and mitosis?
synapsis occurs
DNA replication occurs in _____.
the S phase of interphase in both somatic and reproductive cells
Sunlight is essential for the varied life on Earth. Sunlight provides energy to photosynthetic organisms by providing __________.
the energy necessary to power the rearrangement of chemical bonds in H2O and CO2
Crossing over is _____.
the exchange of homologous portions of nonsister chromatids
Where do the reactions of the citric acid cycle occur in eukaryotic cells?
the mitochondrion
What would be the immediate consequence of destroying a cell's centrosomes?
the mitotic spindle wouldn't form
The enzyme ATP synthase catalyzes the phosphorylation of ADP to form ATP. In eukaryotic cells, the energy needed for this endergonic reaction is directly derived from __________.
the movement of hydrogen ions across the mitochondrial membrane
When chloroplast pigments absorb light, _____.
their electrons become excited
Oxidative phosphorylation could not occur without glycolysis and the citric acid cycle, because _____.
these two stages supply the electrons needed for the electron transport chain
Within one chromosome, what is the relationship between the sequence of bases in DNA of one sister chromatid compared to the other?
they are identical
During mitosis, the chromosomes move because _____
they attach to a dynamic, precisely regulated mitotic spindle
Chlorophyll is found in the __________ of chloroplasts.
thylakoid membranes
Chlorophyll molecules are found in which part of the chloroplast?
thylakoid membranes
Both mitochondria and chloroplasts _____.
use an H+ gradient to produce ATP
Homologous chromosomes possess the same genes arranged in the same order but may possess different __________ of some of these genes.
versions
Where do the electrons needed by photosystem II originate?
water