Chapter 9 The Links in Life's Chain: Genetics and Cell Division
Updated: Aug 20, 2022
1) The study of physical inheritance among living things is:
A) proteomics.
B) genomics.
C) genetics.
D) reproduction.
Answer: C
Topic: Section 9.1
Skill: Knowledge/Comprehension
2) The complete collection of an organism's genetic information constitutes:
A) a chromosome.
B) proteins.
C) a gene.
D) a genome.
Answer: D
Topic: Section 9.1
Skill: Knowledge/Comprehension
3) The ordering of bases in a gene determines the order of:
A) amino acids in a protein.
B) mRNAs on a ribosome.
C) genes on a chromosome.
D) genes in a genome.
Answer: A
Topic: Section 9.1
Skill: Knowledge/Comprehension
4) The order of bases in a gene is copied to make a/an:
A) amino acid.
B) gene.
C) mRNA.
D) ribosome.
Answer: C
Topic: Section 9.1
Skill: Knowledge/Comprehension
5) Which molecule is made in the nucleus but exits to function in the cytoplasm?
A) chromosome
B) protein
C) mRNA
D) gene
Answer: C
Topic: Section 9.1
Skill: Knowledge/Comprehension
6) What distinguishes one gene from another?
A) the length of the chromosome the gene is on
B) the order of bases in the gene
C) the position of the gene on a chromosome
D) the order of amino acids of which the genes are made
Answer: B
Topic: Section 9.1
Skill: Knowledge/Comprehension
7) The information used to make proteins is encoded by the:
A) number of different chromosomes.
B) repeating sugar and phosphate molecules in DNA.
C) 20 different amino acids of proteins.
D) four bases A, T, G, or C.
Answer: D
Topic: Section 9.1
Skill: Knowledge/Comprehension
8) The number of genes in the human genome is estimated to be:
A) 20,000 to 25,000.
B) 3 billion.
C) 3 to 6 million.
D) 1 million.
Answer: A
Topic: Section 9.1
Skill: Knowledge/Comprehension
9) What would be the consequence if one base were changed in the base sequence of a DNA molecule?
A) Messenger RNA would correct the mistake.
B) Genome copying would be impossible.
C) Protein synthesis would stop.
D) A defective protein could be produced.
Answer: D
Topic: Section 9.1
Skill: Application/Analysis
10) Which of the following is the proper sequence of events in gene expression?
A) protein → DNA → mRNA
B) mRNA → DNA → protein
C) DNA → protein → mRNA
D) DNA → mRNA → protein
Answer: D
Topic: Section 9.1
Skill: Knowledge/Comprehension
11) A gene is a hereditary unit that carries information for:
A) another gene.
B) a sequence of sugars.
C) a sequence of amino acids.
D) a sequence of nucleotides.
Answer: C
Topic: Section 9.1
Skill: Knowledge/Comprehension
12) What is the initial step in DNA replication?
A) breakdown of the nuclear envelope
B) formation of the mitotic spindle
C) formation of the cleavage furrow
D) unwinding of the DNA double helix
Answer: D
Topic: Section 9.2
Skill: Knowledge/Comprehension
13) During DNA replication, what acts as the template for synthesis of a new strand of DNA?
A) a single strand of DNA
B) a ribosome
C) a single strand of mRNA
D) a single strand of rRNA
Answer: A
Topic: Section 9.2
Skill: Knowledge/Comprehension
14) Choose the statement that is correct about the frequency of mitosis.
A) All cells divide throughout the existence of a multicellular eukaryote.
B) Some cells, such as leaf cells, cease to divide after mature size is reached.
C) Bone marrow cells are an example of cells that cease to divide after maturity.
D) Brain cells are easy to replace because they divide frequently after maturity.
Answer: B
Topic: Section 9.2
Skill: Knowledge/Comprehension
15) At what point in the cell cycle does DNA replication take place?
A) during mitosis
B) continually throughout the cell cycle
C) during cytokinesis
D) before mitosis
Answer: D
Topic: Section 9.2
Skill: Knowledge/Comprehension
A) to turn skin cells into hair cells
B) to keep cell size small as multicellular organisms grow
C) to allow cell size to increase to its maximum
D) to allow mature leaves to increase in size
Answer: B
Topic: Section 9.2
Skill: Knowledge/Comprehension
17) The replication of a DNA molecule results in:
A) two DNA molecules, each with one old and one new strand.
B) two DNA molecules, one being made of the old strands and one being made of two new strands.
C) two DNA molecules, both of which are made of completely new strands.
D) four unwound DNA strands.
Answer: A
Topic: Section 9.2
Skill: Knowledge/Comprehension
18) What is the relationship between genes and chromosomes?
A) Chromosomes are proteins that carry genes made of DNA.
B) Genes are the proteins encoded by chromosomes.
C) Genes are the proteins around which DNA chromosomes are packaged.
D) A chromosome is a DNA molecule with many genes.
Answer: D
Topic: Section 9.3
Skill: Knowledge/Comprehension
19) If a cell with two nuclei were discovered, which of the explanations below would be true?
A) Mitosis occurred without cytokinesis.
B) The cell remained in interphase continuously.
C) Meiosis and mitosis both occurred.
D) Cytokinesis occurred without mitosis.
Answer: A
Topic: Section 9.3
Skill: Application/Analysis
20) What is the relationship between DNA and chromatin?
A) Chromatin is the collection of proteins encoded by DNA.
B) A chromatin is a DNA molecule that is separated during mitosis.
C) A chromatin is a unit of DNA whose sequence encodes a protein.
D) Chromatin is the combination of DNA packaged around proteins.
Answer: D
Topic: Section 9.3
Skill: Knowledge/Comprehension
21) During S phase, chromosomes are converted to what form?
A) karyotypes
B) sister chromatids
C) chromatin
D) centrosomes
Answer: B
Topic: Section 9.3
Skill: Knowledge/Comprehension
22) Normal cell operations and growth occur during the "gap" period called:
A) G3.
B) M.
C) S.
D) G1.
Answer: D
Topic: Section 9.3
Skill: Knowledge/Comprehension
23) Chromosome I from your mother and chromosome I from your father are said to be homologous. This is because the chromosomes:
A) appear the same size in a karyotype.
B) have different genes on them.
C) have the same genes on them.
D) determine the sex of the child.
Answer: C
Topic: Section 9.3
Skill: Knowledge/Comprehension
24) A karyotype:
A) shows chromosomes as they appear before replication.
B) can reveal the location of a gene.
C) can show the number of chromosomes in a cell.
D) can reveal the presence of cancerous genes.
Answer: C
Topic: Section 9.3
Skill: Knowledge/Comprehension
25) Why do karyotypes always show chromosomes at the point when cell division is about to occur?
A) This is the only cell cycle point in which the chromosomes are unduplicated.
B) The chromosomes are easier to see when they are elongated and uncondensed.
C) This is the time at which the chromosomes are being duplicated.
D) The chromosomes are fully condensed as cell division approaches.
Answer: D
Topic: Section 9.3
Skill: Knowledge/Comprehension
26) Which cell cycle stage is not part of interphase?
A) G2
B) M
C) G1
D) S
Answer: B
Topic: Section 9.3
Skill: Knowledge/Comprehension
27) A liver cell from a human male has:
A) 22 pairs of autosomes, an X chromosome, and a Y chromosome.
B) 22 pairs of autosomes and two X chromosomes.
C) 46 pairs of autosomes, an X chromosome, and a Y chromosome.
D) 23 pairs of autosomes and two X chromosomes.
Answer: A
Topic: Section 9.3
Skill: Knowledge/Comprehension
28) The "gap" phases of the cell cycle are devoted to:
A) moving chromosomes to their correct positions.
B) normal cell operations, growth, and preparation for cell division.
C) DNA replication.
D) creating new nuclei.
Answer: B
Topic: Section 9.3
Skill: Knowledge/Comprehension
29) What is being separated during anaphase of mitosis?
A) plasma membranes
B) sister chromatids
C) nuclear membranes
D) cytoplasm
Answer: B
Topic: Section 9.4
Skill: Knowledge/Comprehension
30) Which cell structure physically moves the cell's chromosomes?
A) the plasma membrane
B) the cell wall
C) the mitotic spindle
D) the contractile ring
Answer: C
Topic: Section 9.4
Skill: Knowledge/Comprehension
31) If a cell contains 20 chromosomes, how many chromatids will be present during prophase?
A) 30
B) 20
C) 5
D) 40
Answer: D
Topic: Section 9.4
Skill: Application/Analysis
32) Some anticancer chemotherapy agents interfere with the proper functioning of microtubules. How do these anticancer chemotherapy agents work?
A) They inhibit the mitotic spindle and prevent cell division.
B) They inhibit the contractile ring and prevent cell division.
C) They inhibit telophase because microtubules are required to form nuclear envelopes.
D) Microtubules replicate DNA, so they inhibit chromosome duplication.
Answer: A
Topic: Section 9.4
Skill: Application/Analysis
33) During metaphase, chromosomes that are attached to microtubules are observed to undergo a "back-and-forth" movement. What is happening during this movement?
A) The chromosomes are being replicated.
B) The centrosome is being replicated.
C) The chromosomes are being aligned at the equator of the cell.
D) The chromosomes are breaking up the nuclear membrane.
Answer: C
Topic: Section 9.4
Skill: Knowledge/Comprehension
34) What event typically begins in anaphase and is completed soon after the end of telophase?
A) interphase
B) alignment of chromosomes at the cell equator
C) packing of DNA into well-defined chromosomes
D) cytokinesis
Answer: D
Topic: Section 9.4
Skill: Knowledge/Comprehension
35) Microtubule-organizing centers will begin to migrate toward the cell poles during:
A) prophase.
B) metaphase.
C) anaphase.
D) telophase.
Answer: A
Topic: Section 9.4
Skill: Knowledge/Comprehension
36) What would be the result of an error in anaphase that failed to separate a pair of sister chromatids?
A) The nuclear envelope would not be able to break down.
B) One cell would have an extra gene, and one cell would be missing one gene.
C) One cell would have an extra chromosome, and one cell would lack a chromosome.
D) Cytokinesis would not be able to take place, and the cells would not divide.
Answer: C
Topic: Section 9.4
Skill: Application/Analysis
37) Chromosomes are aligned at the equator of a cell during:
A) prophase.
B) metaphase.
C) anaphase.
D) telophase.
Answer: B
Topic: Section 9.4
Skill: Knowledge/Comprehension
38) Which of the following structures is involved in forming a cleavage furrow?
A) sister chromatids
B) mitotic spindle
C) metaphase plate
D) contractile ring
Answer: D
Topic: Section 9.4
Skill: Knowledge/Comprehension
39) The chromosomes become visible and the nucleus starts to break up during:
A) prophase.
B) metaphase.
C) anaphase.
D) telophase.
Answer: A
Topic: Section 9.4
Skill: Knowledge/Comprehension
40) Which statement is true of mitosis and cytokinesis in normal tissues?
A) Cytokinesis partially overlaps with mitosis.
B) Cytokinesis occurs simultaneously with mitosis.
C) Mitosis precedes cytokinesis.
D) Cytokinesis precedes mitosis.
Answer: A
Topic: Section 9.4
Skill: Knowledge/Comprehension
41) Sister chromatids are separating from each other during:
A) prophase.
B) metaphase.
C) anaphase.
D) telophase.
Answer: C
Topic: Section 9.4
Skill: Knowledge/Comprehension
42) A cell is observed under the microscope. What feature will indicate that it has just reached the end of interphase?
A) a visible contractile ring
B) two separate cells
C) elongated, noncondensed chromosomes that are difficult to visualize
D) chromosomes that are becoming well defined and visible
Answer: D
Topic: Section 9.4
Skill: Knowledge/Comprehension
43) A cell is observed under the microscope. What feature will indicate that it is in anaphase?
A) DNA is elongated, not condensed, and difficult to visualize.
B) Two separate nuclear membranes are visible.
C) Centrosomes are just beginning to separate and form the spindle.
D) Sister chromatids are separating.
Answer: D
Topic: Section 9.4
Skill: Knowledge/Comprehension
44) If a cell with 16 chromosomes undergoes mitosis, how many chromosomes will each daughter cell have?
A) 8
B) 4
C) 32
D) 16
Answer: D
Topic: Section 9.4
Skill: Knowledge/Comprehension
45) What would happen if the cell cycle proceeded normally except cytokinesis did not occur?
A) The absence of cytokinesis would inhibit mitosis.
B) The G1 and G2 phases would become shorter.
C) Cells without nuclei would be formed.
D) A large cell with multiple nuclei would result.
Answer: D
Topic: Section 9.4
Skill: Application/Analysis
46) While looking under a microscope, you see two neighboring daughter cells. One of the cells contains three chromosomes, and the other contains five. The parent cell normally contains four chromosomes. What could be the reason for the different number of chromosomes in the cells?
A) The division of sister chromatids of one chromosome did not occur properly during mitosis.
B) The nuclear envelope did not dissolve, so mitosis could not occur at all.
C) Replication of DNA did not occur properly.
D) The division of homologous chromosomes during meiosis II did not occur properly.
Answer: A
Topic: Section 9.4
Skill: Application/Analysis
47) Chromosomes uncoil and new nuclei form during:
A) prophase.
B) metaphase.
C) anaphase.
D) telophase.
Answer: D
Topic: Section 9.4
Skill: Knowledge/Comprehension
48) How do daughter cells at the end of mitosis and cytokinesis compare with the parent cell before DNA replication occurs?
A) The daughter cells may have the same number of chromosomes but double the amount of DNA.
B) The daughter cells have the same number of chromosomes and the same amount of DNA.
C) The daughter cells have half the number of chromosomes and half the amount of DNA.
D) The daughter cells have half the amount of cytoplasm and half the number of chromosomes.
Answer: B
Topic: Section 9.4
Skill: Application/Analysis
49) Why is prokaryotic cell division fundamentally different from eukaryotic cell division?
A) Prokaryotic cells divide for several months and then live for decades without dividing.
B) Prokaryotic cells do not have a plasma membrane.
C) Prokaryotes have many more chromosomes to divide.
D) Prokaryotic cells have a single chromosome and no nuclear membrane.
Answer: D
Topic: Section 9.5
Skill: Knowledge/Comprehension
50) What is one of the differences between cell division in plant cells and cell division in animal cells?
A) Plant cells separate chromosomes by attachment to the plasma membrane.
B) There is no DNA replication before cell division in plant cells.
C) Plant cells do not use a mitotic spindle to separate chromosomes.
D) Plant cells separate by the formation of a new plasma membrane and cell wall in the middle of the cell.
Answer: D
Topic: Section 9.5
Skill: Knowledge/Comprehension
51) What is one of the similarities between prokaryotic and eukaryotic cell division?
A) DNA is unwound and duplicated by the same process.
B) Microtubules separate the chromosomes.
C) One cell divides into four cells.
D) At the end of cell division, nuclear membranes form around the chromosomes.
Answer: A
Topic: Section 9.5
Skill: Knowledge/Comprehension
52) Which statement about binary fission is true?
A) It occurs during S phase of the cell cycle.
B) It is the cell division process of both prokaryotic and eukaryotic cells.
C) It is the cell division process of prokaryotic cells.
D) It is part of interphase.
Answer: C
Topic: Section 9.5
Skill: Knowledge/Comprehension
53) Which of the following organisms would reproduce by binary fission?
A) plants
B) animals
C) fungi
D) bacteria
Answer: D
Topic: Section 9.5
Skill: Knowledge/Comprehension
54) A cell plate is forming across the middle of a cell and new nuclei are forming at the poles. What kind of cell is this?
A) an animal cell going through cytokinesis
B) an animal cell during telophase
C) a bacterial cell
D) a plant cell during metaphase
E) a plant cell going through cytokinesis
Answer: E
Topic: Section 9.5
Skill: Application/Analysis
55) The human genome is estimated to include 20,000 to 25,000 genes.
Answer: TRUE
Topic: Section 9.2
Skill: Knowledge/Comprehension
56) Anaphase is characterized by the separation of sister chromatids.
Answer: TRUE
Topic: Section 9.4
Skill: Knowledge/Comprehension
57) Compact chromosomes first become visible during metaphase.
Answer: FALSE
Topic: Section 9.4
Skill: Knowledge/Comprehension
58) During the cell cycle of a eukaryotic cell, each chromosome is replicated to become a chromosome with two chromatids, and then the chromatids are pulled apart to form two separate chromosomes.
Answer: TRUE
Topic: Section 9.4
Skill: Knowledge/Comprehension
59) When a dividing human cell reaches telophase, 23 nuclear membranes must form, one for each pair of chromosomes.
Answer: FALSE
Topic: Section 9.4
Skill: Knowledge/Comprehension
60) The chief accomplishment of telophase is the organization of chromosomes into new nuclei.
Answer: TRUE
Topic: Section 9.4
Skill: Knowledge/Comprehension
61) Bacterial binary fission is essentially the same process as mitosis in animals and plants.
Answer: FALSE
Topic: Section 9.5
Skill: Knowledge/Comprehension
62) During the cytokinesis phase of cell division, plant cells develop a cell plate instead of a cleavage furrow.
Answer: TRUE
Topic: Section 9.5
Skill: Knowledge/Comprehension
Match the following.
A) metaphase
B) telophase
C) prophase
D) cytokinesis
E) anaphase
63) Chromosomes condense and the mitotic spindle begins to form
Topic: Section 9.4
Skill: Knowledge/Comprehension
64) Microtubules shorten and the genetic material divides
Topic: Section 9.4
Skill: Knowledge/Comprehension
65) The nuclear envelope has disappeared completely and sister chromatids are facing opposite poles
Topic: Section 9.4
Skill: Knowledge/Comprehension
66) A contractile ring is narrowing along the cell's equator
Topic: Section 9.4
Skill: Knowledge/Comprehension
67) Chromosomes unwind and new nuclei form
Topic: Section 9.4
Skill: Knowledge/Comprehension
Answers: 63) C 64) E 65) A 66) D 67) B
68) The ________ of an organism is its complete collection of genetic information.
Answer: genome
Topic: Section 9.1
Skill: Knowledge/Comprehension
69) The sequence of events from the birth of a cell to when it divides describes the ________.
Answer: cell cycle
Topic: Section 9.3
Skill: Knowledge/Comprehension
70) The ________ is a microtubule structure that binds to sister chromatids to separate them in anaphase.
Answer: mitotic spindle
Topic: Section 9.4
Skill: Knowledge/Comprehension
71) In cell division, the separation of duplicated chromosomes is ________.
Answer: mitosis
Topic: Section 9.4
Skill: Knowledge/Comprehension
72) In cell division, the separation of the cell's cytoplasm to produce two daughter cells is ________.
Answer: cytokinesis
Topic: Section 9.4
Skill: Knowledge/Comprehension
73) Human skin cells and human white blood cells of the immune system both perform protective functions. Skin cells function primarily in external physical protection, whereas white blood cells function primarily in internal protection. Nonetheless, both types of cells contain a complete copy of the human genome. Explain how cells can have the same genetic information and yet perform different functions. What prevents skin cells from making all the same proteins of a white blood cell?
Answer: Even though almost all cells contain the same genome, different genes are active in the different types of cells. In skin cells, only certain genes are transcribed to produce physically protective proteins. The genes encoding the specialized proteins of a white blood cell are not active, for example; they are not transcribed.
Topic: Section 9.1
Skill: Application/Analysis
74) What is the relationship between genes and proteins, including the function of each?
Answer: Genes specify the amino acid sequence of proteins, whereas proteins carry out the cellular functions.
Topic: Section 9.1
Skill: Application/Analysis
75) At several points in the cell cycle there are checkpoints that control the cell's passage from one phase to the next. If a cell receives a signal at each checkpoint, it continues to the next phase; if it does not receive the signal, the cell does not continue. For example, a growth factor may stimulate a cell to move from G1 into S phase. If no growth factor is present, the cell cycle stops in G1 and the cell does not divide. Predict what would happen to a cell and to a multicellular organism if there was a defect at the checkpoint and the cell continued through the cell cycle even in the absence of a signal.
Answer: If a cell cycle checkpoint is defective, then the cell will continue to divide even when it's not supposed to. This is uncontrolled cell division. In a multicellular organism this would lead to abnormal growths of cells, producing tumors and cancer.
Topic: Section 9.3
Skill: Synthesis/Evaluation
76) Each phase of the cell cycle takes a different amount of time for a cell to complete. The longer the length of the phase, the more likely you will find a cell in that phase. You are looking at some animal cells under the microscope, and you see cells at different phases of the cell cycle. You count how many are in each phase and find out that 90 percent are in interphase, 6 percent are in prophase, 1.5 percent are in metaphase, 0.5 percent are in anaphase, and 2 percent are in telophase. If the length of the cell cycle is 24 hours, how long does it take for the cells to go through each of these phases of the cell cycle?
Answer: If 90 percent of the cells are in interphase, then they spend 90 percent of the 24-hour cell cycle in interphase, which is 21.6 hours. Likewise, prophase takes 1.4 hours, metaphase takes 36 minutes, anaphase takes 12 minutes, and telophase takes 48 minutes.
Topic: Section 9.3
Skill: Application/Analysis
77) During which phase of mitosis are the chromosomes aligned along the equator of the cell? Predict what would happen if a cell completed mitosis without first lining up all the chromosomes in the middle of the cell.
Answer: The chromosomes are aligned along the equator of the cell during metaphase. The purpose of lining up chromosomes along the metaphase plate is to ensure that chromosomes are evenly divided between the two daughter cells. If the chromosomes are not lined up first, then there will likely be an uneven distribution of chromosomes, with one daughter cell having too many and the other daughter cell having too few.
Topic: Section 9.4
Skill: Synthesis/Evaluation
78) You are a physician treating a patient with cancer. Traditional chemotherapy has not been working on this patient, so you prescribe a new class of drugs called taxanes, which inhibit microtubule function. Your patient asks you how they work. How would you explain to your patient how these drugs work?
Answer: Microtubules are involved in moving chromosomes around during cell division. Taxanes are a class of drugs that interfere with the microtubules, preventing them from moving chromosomes, which stops cell division. Cancer is unregulated cell growth, so stopping cell division stops the growth of the cancer.
Topic: Section 9.4
Skill: Application/Analysis
79) List and briefly describe three differences between prokaryotic and eukaryotic cell division.
Answer: (1) Prokaryotic cells have a single circular chromosome–one piece of DNA instead of the several separate chromosomes of eukaryotic cells. Mitosis is not necessary to separate chromosomes, because they simply attach to the plasma membrane to be separated as the cell grows. (2) Prokaryotic chromosomes are not in a nucleus. There is no membrane around the cells to break up during chromosome division. (3) Prokaryotic chromosomes are not separated by attachment to a microtubule spindle. They separate by attachment to the plasma membrane. (4) Prokaryotic cells do not separate by formation of a cleavage furrow. The cell wall and plasma membrane grow inward to eventually separate a single cell into two cells.
Topic: Section 9.5
Skill: Knowledge/Comprehension
Refer to the figure below, and then answer the question that follows.
80) What is the advantage of chromatin coiling and condensing into tight structures before mitosis?
Answer: Compact bodies are much easier to manipulate during mitosis than are long, thin threads, and compact bodies prevent the chromosome from getting tangled and breaking.
Topic: Section 9.3
Skill: Application/Analysis