Chapter 9 + 10

All of the following happen during mitosis except: a) synthesis of DNA. b) separation of sister chromatids at the centromeres. c) condensing of chromosomes. d) formation of the spindle.

a

Besides the ability of some cancer cells to divide uncontrollably, what else could logically result in a tumor? a) lack of appropriate cell death b) enhanced anchorage dependence c) changes in the order of cell cycle stages d) inability to form spindles

a

Select all that are true statements. a) Sexual life cycles include both haploid and diploid stages. b) One major difference between metaphase I and metaphase II is the presence or absence of bivalents. c) A cell undergoing meiosis that contains sister chromatids may be either haploid or diploid. d) Sexually reproducing organisms do not use mitosis.

a b c

Select all of the following statements about the mitotic phase of the cell cycle are true. a) Cytokinesis follows mitosis. b) DNA replication is completed prior to the beginning of this phase. c) The chromosome number of the resulting cells is the same as that of the parent cell. d) The daughter cells are usually genetically identical to the parental cell. e) G2 happens during mitosis

a b c d

Which of the following statements about kinetochores on mitotic chromosomes is true? (select all that apply) a) They are located at the centromere of each chromosome. b) Microtubules are excluded from binding DNA by kinetochores. c) They are organized so that there is one per sister chromatid. d) Kinetochore microtubules from opposite poles attach to each sister chromatid. e) Kinetochores and microtubules push on the cell membrane during cytokinesis.

a c d

Select all the stages of the cell cycle that make up interphase. a) S phase b) mitosis c) G1 d) cytokinesis e) G2

a c e

At the end of meiosis II, each of the four resulting cells contains a) one full set of chromosomes, each with 2 molecules of DNA b) one full set of chromosomes, each with 1 molecule of DNA c) two full sets of chromosomes, each with 1 molecule of DNA d) two full sets of chromosomes, each with 2 molecules of DNA

b

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 a) synapsis b) crossing over c) independent assortment d) syngamy

b

How does the organization of the bacterial genome differ from the organization of the eukaryotic genome? a) The eukaryotic genome is found on chromosomes and there are no chromosomes in bacterial cells. b) Most bacterial chromosomes are circular and the eukaryotic chromosomes contained in the nucleus are not. c) Bacterial genomes are typically much larger than eukaryotic genomes. d) Bacterial chromosomes are made up of RNA and eukaryotic chromosomes are made up of DNA. e) Eukaryotic chromosomes have to be tightly packed to fit into the nucleus, and bacterial chromosomes do not require tight packing to fit into the cell.

b

If you treated growing cells in tissue culture with a chemical that activated ______, cells would stall during the cell cycle and never synthesize DNA. a) the M checkpoint b) the G1 checkpoint c) the G2 checkpoint

b

In plants and animals, the zygote develops into an embryo by what process? a) meiosis b) mitosis c) syngamy d) synapsis e) reduction division

b

Most animal cells exhibit anchorage dependence, which means that in order to divide a) all chromosomes must be attached to spindle microtubules. b) cells must be attached to a substrate or extracellular matrix of a tissue. c) nonkinetochore microtubules from opposite poles must overlap and be attached by motor proteins. d) cell-surface phospholipids must be attached to those of adjoining cells.

b

Researchers began a study of a cultured cell line. Their preliminary observations showed them that the cell line did not exhibit either density-dependent inhibition or anchorage dependence. What could they conclude right away? a) The cells have altered series of cell cycle phases b) The cells show characteristics of tumors c) The cells were originally derived from an elderly organism d) The cells originated in the nervous system

b

This stage of mitosis is characterized by the disassembly of spindle apparatus, the reestablishment of the nuclear membrane, and the decondensation of the chromosomes: a) Anaphase b) Telophase c) Prometaphase d) Metaphase e) Prophase

b

Which of the following statements about the cell cycle is correct? a) During G2 phase, the cell grows and copies its chromosomes in preparation for cell division. b) When the S phase of the cell cycle is finished, a cell has twice as many chromatids as the number of chromosomes in the G1 phase. c) The phases of the cell cycle are G1, S, and M phases. d) In actively dividing cells, the S and G2 phases are collectively known as interphase. e) The cell cycle is a sequence of replications and divisions that produces a new cells.

b

Which of the following statements is FALSE concerning sister chromatids? a) Sister chromatids are held together at the centromere by kinetochore proteins. b) Sister chromatids separate during telophase. c) Sister chromatids are formed during the S phase of the cell cycle. d) Sister chromatids consist of two identical copies of a single homologue. e) The formation of sister chromatids doubles the amount of DNA in a cell.

b

_____ mutations affect only the individual in which they occur; _____ mutations are passed from parent to offspring. a) Germ-line; somatic b) Somatic; germ-line c) Somatic; point d) Germ-line; heritable e) Point; germ-line

b

If you treated growing cells in tissue culture with a chemical that activated______, cells would stall during the cell cycle and with replicated DNA. Check all that apply. a) the G1 checkpoint b) M checkpoint c) the G2 checkpoint

b c

Density-dependent inhibition is explained by which of the following? a) As cells become more numerous, the level of waste products increases, eventually slowing down metabolism. b) As cells become more numerous, the protein kinases they produce begin to compete with each other, such that the proteins produced by one cell essentially cancel those produced by its neighbor. c) As cells become more numerous, the cell surface proteins of adjacent cells bind to each other and send signals that inhibit cell division. d) As cells become more numerous, the protein kinases they produce begin to compete with each other, such that the proteins produced by one cell essentially cancel those produced by its neighbor.

c

In meiosis II, a) chromosomes do not condense. b) four genetically identical cells are generated. c) sister chromatids are separated. d) DNA replication occurs. e) crossing over occurs

c

The process of nuclear division which reduces the number of chromosomes per cell from 2 sets to 1 set, is called a) Mitosis b) Syngamy c) Meiosis d) Binary fission

c

Which of the following statements about chiasmata is true? a) They are sites where nonsister chromatids can exchange genetic material during meiosis and increase genetic variation in gametes. b) They are sites where sister chromatids can exchange genetic material during meiosis and increase genetic variation in gametes. c) They increase genetic variation among the gametes due to exchange between all members of the tetrad during meiosis. d) They increase genetic variation among the gametes due to exchange between all members of the tetrad during mitosis. e) All of the potential answers are true.

c

Which of the following statements regarding the G1 (first gap) phase of the eukaryotic cell cycle is NOT true? a) The G1 phase is only part of interphase. b) Most cells spend the majority of their lives in the G1 phase of the cell cycle. c) If environmental conditions are favorable during the G1 phase, G1 cyclins are degraded causing the cell to prepare to replicate its DNA. d) Cells that are terminally differentiated and will not divide mitotically might exit the G1 phase and enter the G0 phase. e) All of the potential answers are true.

c

The cell produced by the fusion of an egg and a sperm is the a) oocyte b) somatic cell c) germ line cell d) zygote e) gamete

d

The two copies of each type of chromosome found in normal somatic (body) cells in an organism, throughout the cell cycle, are called a) Son chromosomes b) Sister chromatids c) Kinetochores d) Homologous chromosomes e) Daughter chromosomes

d

The zygote has a) chromosomes identical only to those of a sperm cell b) one copy of each chromosome c) chromosomes identical only to those of an egg cell d) two copies of each chromosome e) one full haploid complement of chromosomes

d

When observing some fibroblasts in culture, you notice that cell counts stop once the cells reach 100 per square centimeter. You are observing a) interphase. b) the M checkpoint. c) prophase. d) density-dependent inhibition. e) the action of growth factors

d

Which of the following statements about chromatids is true? a) They are replicated chromosomes still joined together at the centromere. b) They are identical in mitotic chromosomes. c) They undergo recombination in mitosis. d) They are identical in meiotic chromosomes. e) They are replicated chromosomes still joined together at the centromere AND they are identical in mitotic chromosomes.

e