Chapter 8 Biology Review

During which phase of mitosis do the chromosomes line up on a plane equidistant from the two spindle poles? telophase metaphase prophase anaphase

B

Eukaryotic cells spend most of their cell cycle in which phase? prophase interphase metaphase telophase

B

Gametes are produced by _____. A) Fertilization B) meiosis C) mitosis D) asexual reproduction

B

Which of the following statements correctly describes the timing of DNA synthesis? DNA is synthesized in the S phase of interphase. DNA is synthesized continuously. DNA is synthesized only during mitosis. DNA is synthesized in G2 of interphase immediately preceding mitosis.

A

Which of the following statements regarding mitosis and meiosis is false? Meiosis provides for asexual reproduction. In mitosis, the chromosomes replicate only once in the preceding interphase. Mitosis provides for growth and tissue repair. All the events unique to meiosis occur during meiosis I.

A

With the exception of identical twins, siblings who have the same two biological parents are likely to look similar, but not identical, to each other because they have A) a similar but not identical combination of genes. B) identical genes but different chromosomes. C) the same combination of traits, but different genes. D) identical chromosomes, but different genes.

A

Within one chromosome, what is the relationship between the sequence of bases in DNA of one sister chromatid compared to the other? The sequences are identical. The sequence in one chromatid is complementary to the sequence in the other. The sequences are unrelated. The sequences are similar, but not identical.

A

Asexual and sexual reproduction differ in that sexual reproduction _____. is the only way multicellular organisms can reproduce is the only way single-celled organisms can reproduce can produce great variation among the offspring will produce offspring identical to the parents

C

At the start of mitotic anaphase, equivalent and complete collections of chromosomes have reached the two poles. nuclear envelopes begin to form around the chromosomes. the centromeres of each chromosome come apart. the chromatid DNA replicates.

C

Mature human nerve cells and muscle cells cease dividing after a predetermined number of cell generations. continue to divide throughout their lifetime. are permanently in a state of nondivision. become cancerous more easily than other cell types.

C

The creation of genetically identical offspring by a single parent, without the participation of sperm and egg, is called regeneration. sexual reproduction. asexual reproduction. spontaneous generation.

C

The genetic material is duplicated during the mitotic phase. G1. the S phase. G2.

C

Which of the following helps maintain the structure of chromosomes and control the activity of genes? centromeres the nuclear membrane proteins ribosomes

C

Which of the following statements regarding the differences between mitosis and meiosis is false? Cells produced by mitosis are diploid, whereas cells produced by meiosis are haploid. In mitosis cytokinesis occurs once, whereas in meiosis cytokinesis occurs twice. Crossing over is a phenomenon that creates genetic diversity during mitosis. In meiosis four daughter cells are produced, whereas in mitosis two daughter cells are produced.

C

At a chiasma, two ________ are attached to each other. homologous or non-sister chromatids homologous or sister chromatids non-homologous chromosomes daughter cells

A

During mitosis, the chromosomes move because _____. they attach to a dynamic, precisely regulated mitotic spindle they slide along microfilament bundles they diffuse within the nucleus to areas where they are less concentrated of the duplication of the centrosome

A

During which phase of mitosis does the nuclear envelope re-form? telophase metaphase anaphase prophase

A

Which of the following is a feature of plant cell division that distinguishes it from animal cell division? formation of a cell plate formation of a cleavage furrow lack of cytokinesis production of four (rather than two) new cells per mitotic division

A

Which of the following shows the greatest promise as a cancer chemotherapy agent? a drug that prevents mitotic spindle from forming a drug that prevents tetrad formation a drug that interferes with cellular respiration a drug that prevents crossing over

A

Cancer is not usually inherited because people with cancer usually die before reproducing. the chromosomal changes in cancer are usually confined to somatic cells. the cancerous cells usually interfere with the ability to produce gametes. the causes of cancer are not usually genetic.

B

Eukaryotic chromosomes differ from prokaryotic chromosomes in that they are simpler. are housed in a membrane-enclosed nucleus. are circular in structure. include fewer proteins.

B

Prior to mitosis, each chromosome of a eukaryotic cell consists of a pair of identical structures called chromatin. sister chromosomes. nucleoli. sister chromatids.

B

Sister chromatids are found right after a cell divides. joined together at a centromere. made only of DNA. unique to prokaryotes.

B

The process by which the cytoplasm of a eukaryotic cell divides to produce two cells is called mitosis. cytokinesis. telophase. binary fission.

B

Which of the following features likely accounts for the difference between plant and animal cell cytokinesis? Plant cells have two sets of chromosomes; animal cells have one set of chromosomes. Plant cells have cell walls. Animal cells lack chloroplasts. Animal cells lack the microfilaments required for forming a cleavage furrow.

B

Which of the following statements about nondisjunction is false? In general, a single Y chromosome is enough to produce "maleness." In mammals, extra copies of the Y chromosome are typically inactivated. Women with a single X chromosome have Turner syndrome and are sterile. Nondisjunction in meiosis can affect autosomes and sex chromosomes.

B

Which of the following statements regarding Down syndrome is false? People with Down syndrome usually have a shorter life span than normal. Down syndrome is least likely to be seen in the infants of mothers over 40. Down syndrome is the most common serious birth defect in the United States. Trisomy 21 is the cause of Down syndrome.

B

Which of the following statements regarding cell division is false? A) Cell division is necessary for development to occur. B) Cell division is common in eukaryotes but rare in prokaryotes. C) Cell division is the basis of both sexual and asexual reproduction. D) Cell division can reproduce an entire organism.

B

A diploid organism whose somatic (nonsex) cells each contain 32 chromosomes produces gametes containing _____ chromosomes. A) 8 B) 32 C) 64 D) 16

D

Although in humans there are 22 pairs of autosomal chromosomes, only three different chromosomal trisomies are commonly seen in newborns. Of the remaining 19 autosomes, many trisomies have not been seen in newborns. Why not? These autosomal chromosomes do not contain the same type of DNA or protein that makes up chromosomes susceptible to trisomy. Trisomy for these autosomal chromosomes has no effect and therefore would never be noticed. Trisomy for these other autosomal chromosomes occurs so rarely that it has never been documented. Trisomy for the other autosomal chromosomes is often lethal, and the affected embryos are miscarried.

D

Both mitosis and meiosis are preceded by telophase. prophase. prometaphase. interphase.

D

During meiosis I, homologous chromosomes form a tetrad. What does this accomplish? Crossing over can occur, creating new combinations of chromosomes through their independent alignment across the metaphase plate. It allows for the process of crossing over to occur, which reduces the number of chromosomes present in the cell. A chiasma forms as crossing over occurs, which ultimately reduces the number of chromatids per chromosome. This brings the chromosomes into alignment so that crossing over can create new combinations of genes present on a single chromosome.

D

Karyotyping reveals the presence of cancerous genes. shows chromosomes as they appear in metaphase of meiosis II. examines points of crossing over. can reveal alterations in chromosome number.

D

Nondisjunction occurs when a portion of a chromosome breaks off and is lost. an entire pair of chromosomes is lost during meiosis I. two chromosomes fuse into one. members of a chromosome pair fail to separate.

D

Normal human gametes carry _____ chromosomes. A) 46 B) 23 pairs of C) 46 pairs of D) 23

D

Which of the following occurs during interphase? separation of newly formed DNA to opposite ends of the cell cytokinesis a reduction in the size of the nuclear membrane cell growth and duplication of the chromosomes

D

Which of the following statements regarding sexual and asexual reproduction is true? Cell division only occurs after sexual reproduction. Only offspring from asexual reproduction inherit traits from two parents. Sexual reproduction typically includes the development of unfertilized eggs. Sexual reproduction is more likely to increase genetic variation than is asexual reproduction.

D