Deck 9: The Links in Lifes Chain: Genetics and Cell Division

Question 1

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 1

D

Question 2

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 2

A

Question 3

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 3

A

Question 4

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.

Question 5

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

Question 6

The order of bases in a gene is copied to make a/an:

A) amino acid.
B) gene.
C) mRNA.
D) ribosome.

Question 7

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.

Question 8

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.

Question 9

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.

Question 10

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.

Question 11

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.

Question 12

Which molecule is made in the nucleus but exits to function in the cytoplasm?

A) chromosome
B) protein
C) mRNA
D) gene

Question 13

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

Question 14

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

Question 15

What is a function of cell division?

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

Question 16

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.

Question 17

The complete collection of an organism's genetic information constitutes:

A) a chromosome.
B) proteins.
C) a gene.
D) a genome.

Question 18

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

Question 19

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.

Question 20

The study of physical inheritance among living things is:

A) proteomics.
B) genomics.
C) genetics.
D) reproduction.

Question 21

The chromosomes become visible and the nucleus starts to break up during:

A) prophase.
B) metaphase.
C) anaphase.
D) telophase.

Question 22

Microtubule-organizing centers will begin to migrate toward the cell poles during:

A) prophase.
B) metaphase.
C) anaphase.
D) telophase.

Question 23

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.

Question 24

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.

Question 25

During S phase, chromosomes are converted to what form?

A) karyotypes
B) sister chromatids
C) chromatin
D) centrosomes

Question 26

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.

Question 27

Chromosomes are aligned at the equator of a cell during:

A) prophase.
B) metaphase.
C) anaphase.
D) telophase.

Question 28

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

Question 29

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.

Question 30

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.

Question 31

Normal cell operations and growth occur during the "gap" period called:

A) G3.
B) M.
C) S.
D) G1.

Question 32

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.

Question 33

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.

Question 34

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.

Question 35

What is being separated during anaphase of mitosis?

A) plasma membranes
B) sister chromatids
C) nuclear membranes
D) cytoplasm

Question 36

If a cell contains 20 chromosomes, how many chromatids will be present during prophase?

A) 30
B) 20
C) 5
D) 40

Question 37

Which cell cycle stage is not part of interphase?

A) G2
B) M
C) G1
D) S

Question 38

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

Question 39

Which of the following structures is involved in forming a cleavage furrow?

A) sister chromatids
B) mitotic spindle
C) metaphase plate
D) contractile ring

Question 40

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.

Question 41

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.

Question 42

Sister chromatids are separating from each other during:

A) prophase.
B) metaphase.
C) anaphase.
D) telophase.

Question 43

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

Question 44

Which of the following organisms would reproduce by binary fission?

A) plants
B) animals
C) fungi
D) bacteria

Question 45

The human genome is estimated to include 20,000 to 25,000 genes.

Question 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.

Question 47

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.

Question 48

The chief accomplishment of telophase is the organization of chromosomes into new nuclei.

Question 49

Anaphase is characterized by the separation of sister chromatids.

Question 50

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.

Question 51

Compact chromosomes first become visible during metaphase.

Question 52

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.

Question 53

When a dividing human cell reaches telophase, 23 nuclear membranes must form, one for each pair of chromosomes.

Question 54

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.

Question 55

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

Question 56

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.

Question 57

If a cell with 16 chromosomes undergoes mitosis, how many chromosomes will each daughter cell have?

A) 8
B) 4
C) 32
D) 16

Question 58

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.

Question 59

Chromosomes uncoil and new nuclei form during:

A) prophase.
B) metaphase.
C) anaphase.
D) telophase.

Question 60

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.

Question 61

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?

Question 62

List and briefly describe three differences between prokaryotic and eukaryotic cell division.

Question 63

In cell division, the separation of duplicated chromosomes is ________.

Question 64

The ________ is a microtubule structure that binds to sister chromatids to separate them in anaphase.

Question 65

In cell division, the separation of the cell's cytoplasm to produce two daughter cells is ________.

Question 66

What is the relationship between genes and proteins, including the function of each?

Question 67

Match the following.

A) metaphase
B) telophase
C) prophase
D) cytokinesis
E) anaphase
Microtubules shorten and the genetic material divides

Question 68

During the cytokinesis phase of cell division, plant cells develop a cell plate instead of a cleavage furrow.

Question 69

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.

Question 70

The sequence of events from the birth of a cell to when it divides describes the ________.

Question 71

Match the following.

A) metaphase
B) telophase
C) prophase
D) cytokinesis
E) anaphase
Chromosomes unwind and new nuclei form

Question 72

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?

Question 73

Match the following.

A) metaphase
B) telophase
C) prophase
D) cytokinesis
E) anaphase
The nuclear envelope has disappeared completely and sister chromatids are facing opposite poles

Question 74

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?

Question 75

Refer to the figure below, and then answer the question that follows.
What is the advantage of chromatin coiling and condensing into tight structures before mitosis?

Question 76

Match the following.

A) metaphase
B) telophase
C) prophase
D) cytokinesis
E) anaphase
Chromosomes condense and the mitotic spindle begins to form

Question 77

Match the following.

A) metaphase
B) telophase
C) prophase
D) cytokinesis
E) anaphase
A contractile ring is narrowing along the cell's equator

Question 78

Bacterial binary fission is essentially the same process as mitosis in animals and plants.

Question 79

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.

Question 80

The ________ of an organism is its complete collection of genetic information.