BIO chapter 8

During anaphase I, _____. (see book section: Module 8.13) chromosomes line up in one plane homologues separate and migrate toward opposite poles nuclear membranes re-form sister chromatids separate and migrate toward opposite poles

homologues separate and migrate toward opposite poles

Chromatids are _____. (see book section: Module 8.3) found only in aberrant chromosomes identical copies of each other if they are part of the same chromosome held together by the centrioles not present in the Y sex chromosome, but present in the X sex chromosome

identical copies of each other if they are part of the same chromosome

In humans, the _____ determines the sex of the offspring because _____. (see book section: Module 8.11) female ... only the female has two functional sex chromosomes male ... the male can contribute either an X or a Y chromosome male ... the sperm can fertilize either a female egg or a male egg female ... only the female provides cytoplasm to the zygote

male ... the male can contribute either an X or a Y chromosome

Variation occurs when chromosomes are shuffled in _____. (see book section: Module 8.15) mitosis genetic drift meiosis mutation

meiosis

At which stage of mitosis are chromosomes lined up in one plane in preparation for their separation to opposite poles of the cell? (see book section: Module 8.5) anaphase telophase prophase metaphase

metaphase

Which of the following is a correct representation of an event that occurs in mitosis? (see book section: Module 8.5) metaphase—chromosomes line up on the equatorial plane. prometaphase—there is movement of the chromosomes to the poles. prophase—chromosomes uncoil. anaphase—the nuclear envelope disappears.

metaphase—chromosomes line up on the equatorial plane.

After fertilization, the resulting zygote begins to divide by _____. (see book section: Module 8.12) schizogony mitosis meiosis binary fission

mitosis

Down syndrome can be the result of _____. (see book section: Module 8.20) deletion of chromosome 21 nondisjunction of chromosome 21 during meiosis occurrence of meiosis without cytokinesis a deletion in chromosome 21

nondisjunction

At which point do centrosomes begin to move apart to the opposite poles of the cell in a dividing human liver cell? (see book section: Module 8.5) metaphase prophase G2 phase S phase

prophase

In the telophase of mitosis, the mitotic spindle breaks down and the chromatin uncoils. This is essentially the opposite of what happens in _____. (see book section: Module 8.5) interphase prophase anaphase metaphase

prophase

Crossing over occurs during _____. (see book section: Module 8.13) prophase I prophase II metaphase II metaphase I

prophase I

Crossing over occurs during _____. (see book section: Module 8.17) anaphase I prophase II metaphase I prophase I

prophase I

The kinetochores are _____. (see book section: Module 8.5) located at the center of the centrosome; their function is to organize tubulin into elongated bundles called spindle fibers the primary centromere structures that maintain the attachment of the sister chromatids prior to mitosis found as each spindle interlocks at the cell's equator and then moves apart, causing the cell to elongate sites at which microtubules attach to chromosomes

sites at which microtubules attach to chromosomes

At a critical point in meiosis, the chromosomes do not replicate. This occurs between _____. (see book section: Module 8.13) anaphase I and telophase I prophase I and metaphase I telophase I and prophase II metaphase I and anaphase I

telophase I and prophase II

DNA replication occurs in _____. (see book section: Module 8.4) the G1 phase of interphase in reproductive cells only prophase of both mitosis and meiosis the S phase of interphase metaphase of meiosis only

the S phase of interphase

A cell biologist carefully measured the quantity of DNA in grasshopper cells growing in cell culture. Cells examined during the G2 phase of the cell cycle contained 200 units of DNA. What would be the amount of DNA in one of the grasshopper daughter cells? (see book section: Module 8.4) 50 units 200 units 400 units 100 units

100 units

How many pairs of autosomes do humans have? (see book section: Module 8.11) 23 1 22 2

22

Each cell in an individual with Down syndrome contains _____ chromosomes. (see book section: Module 8.19) 45 24 47 46

47

A human bone marrow cell, in prophase of mitosis, contains 46 chromosomes. There are _____ chromatids. (see book section: Module 8.3) 92 23 46 23 or 46, depending on when during prophase you look

92

Why are individuals with an extra chromosome 21, which causes Down syndrome, more numerous than individuals with an extra chromosome 3 or chromosome 16? (see book section: Module 8.19) Extra copies of the other somatic chromosomes are probably fatal. There are probably more genes on chromosome 21 than on either chromosomes 3 or 16. Nondisjunction of chromosomes 3 and 16 probably occurs more frequently. Down syndrome results in more serious symptoms than either trisomy 3 or trisomy 16.

Extra copies of the other somatic chromosomes are probably fatal.

Which of the following is a key difference between meiosis and mitosis? (see book section: Module 8.14) Chromosomes migrate to opposite poles. Synapsis occurs. Chromosomes condense. Chromosomes align at the metaphase plate.

Synapsis occurs.

The diploid phase of the human life cycle begins with _____. (see book section: Module 8.13) fertilization meiosis mitosis the first division of the zygote

fertilization

Cytochalasin B is a chemical that disrupts microfilament formation. This chemical would interfere with _____. (see book section: Module 8.6) formation of a cleavage furrow DNA replication formation of the cell plate formation of the mitotic spindle

formation of a cleavage furrow

Consider the photograph shown below. You can determine this is a plant cell rather than an animal cell because it has _____.

formed a cell plate

The function of meiosis is to make _____. (see book section: Module 8.14) exact copies of the parent cell four cells with a haploid number of chromosomes four cells with the same chromosome number as the parent cell one cell with twice the number of chromosomes as the parent cell

four cells with a haploid number of chromosomes

When we say that an organism is haploid, we mean that _____. (see book section: Module 8.12) its cells each have one chromosome it has one half of a chromosome its cells each have one set of chromosomes its cells each have two sets of chromosomes

its cells each have one set of chromosomes

In some organisms such as certain fungi and algae, cells undergo mitosis repeatedly without subsequently undergoing cytokinesis. What would be the consequence of this? (see book section: Module 8.6) division of the organism into many cells, most lacking nuclei a decrease in chromosome number large cells containing many nuclei an inability to duplicate DNA

large cells containing many nuclei

The term binary fission is best applied to _____. (see book section: Module 8.2) nuclear chemistry prokaryotes plants mitosi

prokaryotes

One event occurring during prophase is _____. (see book section: Module 8.5) cytokinesis the synthesis of a new nuclear envelope the beginning of the formation of the mitotic spindle the alignment of chromosomes in a single plane

the beginning of the formation of the mitotic spindle

At the end of telophase I of meiosis, as cytokinesis occurs, there are _____. (see book section: Module 8.13) two haploid cells two diploid cells four haploid cells one haploid ovum and three polar bodies

two haploid cells

Chromatids form _____. (see book section: Module 8.5) during the S phase during G1 during G2 at the start of mitosis

during the S phase

Which of the following is a normal human female? (see book section: Module 8.11) XX X XXY XXX

XX

If a fragment of a chromosome breaks off and then reattaches to the original chromosome at the same place but in the reverse direction, the resulting chromosomal abnormality is called _____. (see book section: Module 8.23) a deletion a reciprocal translocation an inversion a nondisjunction

an inversion

Unless the chromosomes were stained to show band patterns, a karyotype would usually be unable to show _____. (see book section: Module 8.18) a missing chromosome an inversion a large part of a chromosome duplicated an extra chromosome

an inversion

A cleavage furrow forms in an animal cell during _____. (see book section: Module 8.6) metaphase anaphase G1 phase cytokinesis

cytokinesis

Cytokinesis refers to _____. (see book section: Module 8.6) division of all the parts of the cell division of the nucleus cell movement division of the cell outside the nuclear material

division of the cell outside the nuclear material

The exchange of parts between nonhomologous chromosomes is called _____. (see book section: Module 8.23) crossing over reciprocal translocation transformation inversion

reciprocal translocation

During anaphase II, _____. (see book section: Module 8.13) the cell is diploid sister chromatids separate and migrate toward opposite poles homologues separate and migrate toward opposite poles nuclear membranes re-form

sister chromatids separate and migrate toward opposite poles

An example of a cell that is 2n is a _____. (see book section: Module 8.12) haploid cell sperm or ovum somatic cell gametophyte

somatic cell

The phase of mitosis during which the chromosomes move toward separate poles of the cell is _____. (see book section: Module 8.5) metaphase telophase anaphase cytokinesis

anaphase

Single sister chromatids are found in cells at mitotic _____. (see book section: Module 8.5) prophase and telophase prophase and anaphase metaphase and anaphase anaphase and telophase

anaphase and telophase

Observations of cancer cells in culture support the hypothesis that cancer cells _____. (see book section: Module 8.9) exhibit anchorage dependence do not exhibit density-dependent inhibition produce molecules that inhibit the growth factors required for cell division divide in a controlled manner

do not exhibit density-dependent inhibition

What is the typical result when a diploid cell undergoes meiosis? (see book section: Module 8.13) two haploid cells four haploid cells two diploid cells four diploid cells

four haploid cells

During asexual reproduction, yeast cells can produce _____. (see book section: Module 8.1) genetically identical offspring gametes with only half as many chromosomes as the parent cell two non-identical offspring gametes with the same number of chromosomes as the parent cell End of Question 1

genetically identical offspring

In anaphase I, _____. (see book section: Module 8.13) the sister chromatids move toward opposite poles the sister chromatids move randomly toward either pole homologous chromosomes move toward opposite poles homologous chromosomes move randomly toward either pole

homologous chromosomes move toward opposite poles