Chapter 8 mastering bio

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

A) the centromeres of each chromosome come apart.

Which of the following statements is false? A zygote is a fertilized egg. Two haploid cells fuse during fertilization. An X chromosome is an autosome. Gametes are haploid cells.

An X chromosome is an autosome.

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

Cell division is common in eukaryotes but rare in prokaryotes.

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 meiosis four daughter cells are produced, whereas in mitosis two daughter cells are produced. Crossing over is a phenomenon that creates genetic diversity during mitosis. In mitosis cytokinesis occurs once, whereas in meiosis cytokinesis occurs twice.

Crossing over is a phenomenon that creates genetic diversity during mitosis.

Without crossing over, A) cells could not complete meiosis. B) meiosis could not produce haploid gametes. C) only a small number of unique gametes could be produced by a single individual. D) genetic recombination could not occur.

D) genetic recombination could not occur.

Which of the following statements regarding Down syndrome is false? Trisomy 21 is the cause of Down syndrome. Down syndrome is the most common serious birth defect in the United States. 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 least likely to be seen in the infants of mothers over 40.

Which of the following statements regarding genetic diversity is false? Genetic diversity is enhanced by random fertilization. Genetic diversity is enhanced by mitosis. Genetic diversity is enhanced by independent orientation of chromosomes at metaphase I. Genetic diversity is enhanced by crossing over during meiosis.

Genetic diversity is enhanced by mitosis.

Which of the following statements about nondisjunction is false? 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. In general, a single Y chromosome is enough to produce "maleness."

In mammals, extra copies of the Y chromosome are typically inactivated.

Which of the following options correctly describes the behavior of a tetrad during anaphase I of meiosis? It goes intact to one pole of the dividing cell. It splits into four chromosomes, which distribute in random pairs to the two poles of the dividing cell. It splits into two pairs of sister chromatids, and one pair goes to each pole of the dividing cell. It splits into two pairs of homologous, nonsister chromatids, and one pair goes to each pole of the dividing cell.

It splits into two pairs of sister chromatids, and one pair goes to each pole of the dividing cell.

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

Meiosis provides for asexual reproduction.

Which of the following statements regarding the function of mitosis is false? Mitosis allows organisms to grow. Mitosis allows organisms to generate genetic diversity. Mitosis allows organisms to repair tissues. Mitosis allows organisms to reproduce asexually.

Mitosis allows organisms to generate genetic diversity.

Which of the following statements regarding mitosis and meiosis is false? Meiosis only occurs in the ovaries and testes. Mitosis produces daughter cells with half the number of chromosomes as the parent cell. All sexual life cycles involve an alternation of diploid and haploid stages. A normal human zygote has 46 chromosomes.

Mitosis produces daughter cells with half the number of chromosomes as the parent cell.

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

Plant cells have cell walls.

Which of the following statements regarding prokaryotes is false? Prokaryotic cells are generally smaller and simpler than eukaryotic cells. Most prokaryotes reproduce by binary fission. In prokaryotes, daughter chromosomes are separated by an active movement away from each other and the growth of a new plasma membrane between them. Prokaryotic chromosomes are more complex than those of eukaryotes.

Prokaryotic chromosomes are more complex than those of eukaryotes.

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

Sexual reproduction is more likely to increase genetic variation than is asexual reproduction.

Which of the following statements regarding the cell-cycle control system is false? The cell-cycle control system receives messages from outside the cell that influence cell division. The cell-cycle control system triggers and controls major events in the cell cycle. The cell-cycle control system includes three key checkpoints to complete a cell cycle. The cell-cycle control system operates independently of the growth factors.

The cell-cycle control system operates independently of the growth factors.

Which of the following must occur for a plant or animal to grow and develop normally? Sufficient light must be available to stimulate cell division. The organism must be able to control the timing and rate of cell division in different parts of its body. The organism must receive a supply of the appropriate hormones from its parents. Sufficient oxygen must be available to stimulate cell division.

The organism must be able to control the timing and rate of cell division in different parts of its body.

Which of the following variations of the sentence "Where is the cat" is most like a chromosomal deletion? Where is the the cat? Where the is cat? Where is cat? Where is cat the the cat?

Where is cat?

Mr. and Mrs. Smith have three sons in elementary school. Two of their children are progressing normally, but their last son, Charles, has been much slower than his siblings at developing speech and language skills. His parents are concerned that he has a learning disability and decide to investigate further. Since some learning disabilities can be genetically based, their pediatrician recommends a chromosomal analysis.The results show that Charles has a trisomy of the sex chromosomes, diagnosed as XYY, which is caused by nondisjunction in the formation of the father's sperm. The nondisjunction resulted in an extra copy of the Y chromosome. The extra copy was passed on to Charles during fertilization. Most often, this chromosomal change causes no unusual physical features or medical problems, but those with trisomy of the sex chromosomes do have a higher than normal risk of delays in learning development. If Charles gets married and starts a family, which of the following chromosomal abnormalities might be found in his children? XO XY XXY XX

XXY

A pair of sex chromosomes found in a human male is most like a bride and groom. a knife, fork, and spoon. a pair of blue jeans. identical twins.

a bride and groom

You are asked to culture an unidentified sample of animal tissue. You notice that the cells seem to fail to exhibit density-dependent inhibition. The source of this tissue sample is most likely the sperm-producing tissue of the testis. skin. a fetal liver. a cancer.

a cancer.

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

a drug that prevents mitotic spindle from forming

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 identical chromosomes, but different genes. a similar but not identical combination of genes. the same combination of traits, but different genes. identical genes but different chromosomes.

a similar but not identical combination of genes.

A karyotype is most like a) photographs of every couple at a high school prom b) a movie showing the stages of the reproductive cycle of a beetle c) a map showing the hidden location of buried treasure d) the answer key to a multiple choice exam

a) photographs of every couple at a high school prom

Mr. and Mrs. Smith have three sons in elementary school. Two of their children are progressing normally, but their last son, Charles, has been much slower than his siblings at developing speech and language skills. His parents are concerned that he has a learning disability and decide to investigate further. Since some learning disabilities can be genetically based, their pediatrician recommends a chromosomal analysis.The results show that Charles has a trisomy of the sex chromosomes, diagnosed as XYY, which is caused by nondisjunction in the formation of the father's sperm. The nondisjunction resulted in an extra copy of the Y chromosome. The extra copy was passed on to Charles during fertilization. Most often, this chromosomal change causes no unusual physical features or medical problems, but those with trisomy of the sex chromosomes do have a higher than normal risk of delays in learning development. During which stage of meiosis could this nondisjunction have occurred? telophase II anaphase II telophase I prophase I

anaphase II

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

are housed in a membrane-enclosed nucleus.

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

are permanently in a state of nondivision.

Strictly speaking, the phrase "like begets like" refers to all forms of reproduction.s exual reproduction only. production of gametes from a premeiotic cell. asexual reproduction only.

asexual reproduction only.

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

asexual reproduction.

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

can reveal alterations in chromosome number.

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

cell growth and duplication of the chromosomes

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

cytokinesis.

As a patch of scraped skin heals, the cells fill in the injured area but do not grow beyond that. This is an example of density-dependent inhibition. growth factor inhibition. anchorage independence. density-independent inhibition.

density-dependent inhibition.

When animal cells are grown in a petri dish, they typically stop dividing once they have formed a single, unbroken layer on the bottom of the dish. This arrest of division is an example of cell division repression. cell constraint. density-dependent inhibition. growth factor desensitization.

density-dependent inhibition.

A benign tumor differs from a malignant tumor in that a benign tumor is cancerous. does not metastasize. never causes health problems. spreads from the original site.

does not metastasize.

Which of the following types of organisms commonly demonstrates polyploidy? reptiles mammals fish flowering plants

flowering plants

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

formation of a cell plate

Two chromosomes in a nucleus that carry genes controlling the same inherited characteristics are complementary chromosomes. heterologous chromosomes. homologous chromosomes parallel chromosomes.

homologous chromosomes

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

homologous or non-sister chromatids

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

interphase

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

interphase.

If a chromosome fragment breaks off and then reattaches to the original chromosome, but in the reverse direction, the resulting chromosomal abnormality is called a(n) reciprocal translocation. translocation. inversion. deletion.

inversion.

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

joined together at a centromere.

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

members of a chromosome pair fail to separate.

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

metaphase

How many generations does it take to develop a new plant species by polyploidy? ten one about twenty two

one

Which of the following is probably the main factor responsible for the phenomenon of density-dependent inhibition? physical contact of cell-surface proteins between adjacent cells a local accumulation of growth-inhibiting factors cells' innate ability to "sense" when the organ of which they are a part has no need for additional cells a local deficiency of nutrients

physical contact of cell-surface proteins between adjacent cells

Independent orientation of chromosomes at metaphase I results in an increase in the number of possible combinations of characteristics. gametes. homologous chromosomes. sex chromosomes.

possible combinations of characteristics.

During which stage of meiosis do synapsis and crossing over occur? interphase I prophase I prophase II metaphase I

prophase I

The phase of mitosis during which the mitotic spindle begins to form is prophase. interphase. anaphase. metaphase.

prophase.

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

proteins

Independent orientation of chromosomes at metaphase I and random fertilization are most like pairing up similar socks after washing your clothes. alphabetizing files in a filing cabinet. cutting up a pie into eight even-sized slices. shuffling cards and dealing out hands of poker.

shuffling cards and dealing out hands of poker.

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

sister chromatids.

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

telophase

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

the S phase.

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

the chromosomal changes in cancer are usually confined to somatic cells.

Looking into your microscope, you spot an unusual cell. Instead of the typical rounded cell shape, the cell has a very narrow middle separating two bulging ends. It sort of looks like the number 8! Then you realize that this cell is in the S phase of interphase. about to undergo mitosis. in the G1 phase of interphase. undergoing cytokinesis.

undergoing cytokinesis.

Asexual reproduction requires ________ individual(s). 3 1 0 2

1