Mastering Biology Chapter 8 Part 2
The M phase of mitosis and M phase of meiosis both occur after interphase. However, the two processes differ in the arrangement and behavior of their chromosomes. How?
The pairing up of homologous chromosomes and crossing over only occur during meiosis.
Meiosis differs from mitosis in that _____ only occurs in meiosis.
crossing over
During prophase I of meiosis,
homologous chromosomes stick together in pairs.
Which processes lead to most genetic variation in sexually reproducing organisms?
independent orientation of chromosomes in meiosis, crossing over, random fertilization
A cell preparing to undergo meiosis duplicates its chromosomes during
interphase.
A fragment of chromosome 21 reattaches to chromosome 21, but in the reverse direction. What is the name given to this change?
inversion
Variation occurs when chromosomes are shuffled in _____.
meiosis
During _____ chromosomes align single file along the equator of a haploid cell.
metaphase II
After fertilization, the resulting zygote begins to divide by __________.
mitosis
During meiosis, homologous chromosomes sometimes "stick together" and do not separate properly. This phenomenon is known as _____.
nondisjunction
The correct order of events during meiosis is
prophase I, metaphase I, anaphase I, telophase I, cytokinesis, meiosis II.
During meiosis, segments of nonsister chromatids can trade places. This recombination of maternal and paternal genetic material is a key feature of meiosis. During what phase of meiosis does recombination occur?
prophase I.
During _____ a spindle forms in a haploid cell.
prophase II
The exchange of parts between nonhomologous chromosomes is called _____.
reciprocal translocation
An example of a cell that is 2n is a __________.
somatic cell
At the end of _____ and cytokinesis, haploid cells contain chromosomes that each consist of two sister chromatids.
telophase I
At the end of _____ and cytokinesis there are four haploid cells.
telophase II
Meiosis I produces _____ cells, each of which is _____.
two ... haploid
Mitosis and cytokinesis result in the formation of __________; meiosis and cytokinesis result in the formation of __________.
two diploid cells : four haploid cells
Homologous chromosomes possess the same genes arranged in the same order but may possess different __________ of some of these genes.
versions
How many pairs of autosomes do humans have?
22
A human somatic cell contains __________ chromosomes.
46
In a cell containing 10 chromosomes, meiosis results in the formation of daughter cells containing __________ chromosomes
5
During meiosis I, homologous chromosomes form a tetrad and crossing over occurs. What is the outcome of crossing over?
Crossing over creates new combinations of genes present on a single chromosome.
Which of the following statements regarding mitosis and meiosis is false?
Meiosis provides for asexual reproduction.
Which of the following statements regarding mitosis and meiosis is false?
Mitosis produces daughter cells with half the number of chromosomes as the parent cell.
Synapsis occurs during _____.
Prophase I
Which of the following is a key difference between meiosis and mitosis?
Synapsis occurs.
Which of the following variations of the sentence "Where is the cat?" is most like a chromosomal inversion?
Where the is cat?
Crossing over is important because it __________.
allows the exchange of different versions of genes between homologous chromosomes
Homologous chromosomes migrate to opposite poles during _____.
anaphase I
During _____ sister chromatids separate.
anaphase II
Meiosis II typically produces _____ cells, each of which is _____.
four ... haploid
Meiosis starts with a single diploid cell and produces
four haploid cells.
In anaphase I, __________.
homologous chromosomes move toward opposite poles
When we say that an organism is haploid, we mean that _____.
its cells each have one set of chromosomes
A karyotype is most like
photographs of every couple at a high school prom.
In meiosis II, _____.
sister chromatids are separated