Deck 9: Genetics and Cell Division

Question 1

What is the relationship between genes and genome?

A) Genomes are proteins that package genes.
B) The genome means the entire collection of genes.
C) Genes are the proteins that package the genome.
D) Genes are the protein enzymes that are encoded by the genome.

Answer 1

The genome means the entire collection of genes.

Question 2

What cell components store the information for the production of proteins?

A) the cytosol
B) the A, T, C, and G bases in DNA
C) the amino acids of DNA
D) the ribosomes

Answer 2

the A, T, C, and G bases in DNA

Question 3

Nucleotides are to ________ as amino acids are to ________.

A) RNA; DNA
B) proteins; RNA
C) DNA; proteins
D) DNA; RNA

Answer 3

DNA; proteins

Question 4

Which molecule is synthesized in the nucleus and has information for producing proteins?

A) a gene
B) a tRNA
C) an rRNA
D) an mRNA

Question 5

What type of cell molecule forms cartilage and hair, can be hormones or transporters, and acts as an enzyme?

A) centrosome
B) RNA
C) protein
D) ribosome

Question 6

What would happen to an undernourished cell that had insufficient amino acids?

A) A shortage of proteins would interfere with the cell's normal functioning.
B) The cell would grow and divide normally using existing proteins.
C) RNA would assume the function of missing proteins.
D) Transcription would stop.

Question 7

What are the results of DNA replication?

A) two DNA molecules, each with one old and one new strand
B) tripling of the cell's DNA content
C) four sister chromatids from one original chromosome
D) eight sister chromatids from one original chromosome

Question 8

Which statement below best describes a difference between a chromosome and a gene?

A) A chromosome and a gene are identical.
B) A gene is one section of a chromosome, and a chromosome may carry many genes.
C) A gene is larger than a chromosome.
D) A chromosome contains the entire DNA of a human, whereas a gene is only a single portion of that DNA.

Question 9

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

A) G₃.
B) M.
C) S.
D) G₁.

Question 10

Which statement about homologous chromosomes is true?

A) They include the two X chromosomes in a female.
B) They are duplicated chromosomes that have not yet been separated.
C) They contain completely different genes.
D) They include the X and Y chromosomes in a male.

Question 11

In cell division, when are mitochondria, lysosomes, ribosomes, and other cell components divided?

A) mitosis
B) S
C) G₂
D) cytokinesis

Question 12

Which cell cycle stage is not part of interphase?

A) G₂
B) M
C) G₁
D) S

Question 13

What is chromatin?

A) protein filaments that create the cleavage furrow
B) the structure that lies outside the plasma membrane of a plant cell
C) a single strand of DNA that will be a template in replication
D) a combination of uncondensed DNA and the protein around which it is wrapped

Question 14

In a typical animal cell, the cell cycle phase that is longest is:

A) G₁.
B) G₂.
C) M.
D) S.

Question 15

A single cell is selected from a randomly dividing population of animal cells. Probability is highest that this cell is in:

A) M.
B) G₁.
C) G₂.
D) S.

Question 16

Some anticancer chemotherapy agents interfere with microtubules. How do they 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 17

Which agent or treatment would allow a cell to proceed from G₁ to metaphase and then arrest cell division at metaphase?

A) a treatment that introduces breaks in the DNA
B) a treatment that interferes with the replication of DNA
C) a chemical that prevents contraction of the contractile ring
D) a chemical that disassembles the spindle once it has formed

Question 18

How many nuclear membranes must form when a single dividing cell reaches telophase?

A) four
B) one for each individual chromosome
C) two
D) one for each pair of chromosomes

Question 19

What cell cycle structure would be found in animal cells but not plant cells?

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

Question 20

Which of the following might act to inhibit cancer growth in humans?

A) an increase in nutrients available to the cell
B) a chemical that inhibits cell wall formation
C) a chemical that increases rates of DNA replication
D) a chemical that inhibits microtubule formation

Question 21

What kind of proteins make up the mitotic spindle?

A) microtubules
B) chromatids
C) kinases
D) chromatin

Question 22

While looking under a microscope, you see two neighboring daughter cells. One of the cells contains three chromosomes, and the other contains five. The diploid number of chromosomes in this type of cell is 4. 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 23

You are a contestant on the local biology quiz show, and the $10,000 question is "How do you tell when a cell is undergoing division? The correct answer would be that:

A) amino acids are forming peptide bonds.
B) the DNA is visible in chromosomes.
C) proteins are being produced.
D) alleles are forming new genes.

Question 24

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 amount of chromosomes.

Question 25

Why is it true that not all of an organism's cells go through the cell division cycle?

A) If some cells, such as brain cells, are lost, there is no harm to the organism.
B) Most cells do not have the cellular parts necessary for a proper mitosis.
C) It would be difficult to control the size of the body and its organs.
D) The cells would wear out if they kept dividing.

Question 26

Which types of cells divide by mitosis and cytokinesis?

A) somatic animal cells, but not plant cells
B) prokaryotic and animal cells, but not plant cells
C) plant cells, but not animal cells
D) somatic animal cells, but not prokaryotic cells

Question 27

Fungi (such as mushrooms) are organisms with nuclei and cell walls. You would expect their cell cycle to be most like which of the following organisms?

A) animals
B) plants
C) bacteria
D) Fungi could not have a cell cycle like the above organisms.

Question 28

What is the function of the ras gene in human cells?

A) stimulates or inhibits cell division
B) kills tumor cells
C) destroys DNA
D) repels bacteria that can cause cancer

Question 29

Because cancer is unrestrained cell division, cancer research today focuses mainly on the topic of:

A) replication of DNA.
B) the sequences of bases in the human genes.
C) control of the cell cycle.
D) cytokinesis.

Question 30

Cancer is caused by unrestrained division of cells. The best way to control cancer is to study the mechanism of the:

A) cell cycle and cell growth.
B) environmental system, which may cause cancer.
C) cell communication system.
D) cell defense system.

Question 31

Recent news from the Human Genome Project indicates that humans have about 30,000 genes. This number agrees with information in your textbook.

Question 32

All organisms, from bacteria to plants to humans, have 46 chromosomes.

Question 33

If a tumor suppressor gene is missing from a cell's chromosome, the cell might show unrestrained growth and division.

Question 34

Because cancer cells are continuously in the cell cycle, we would expect them to require more nutrients than nondividing cells.

Question 35

Label and describe the stages of the cell cycle.

Question 36

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, using chemical mechanisms. 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 37

Many proteins have been discovered that monitor DNA replication and prevent cell division unless the DNA is correctly replicated. Why are there so many mechanisms to ensure complete and correct DNA replication?

Question 38

Cell cycle progression is tightly controlled, especially in multicellular organisms such as humans. Think about what happens when a cell divides excessively, and explain why there are many controls and regulatory mechanisms to make sure cells divide only when it is appropriate.