Mastering Biology Chapter 8 Homework

In cytokinesis....

the cytoplasm divides.

In metaphase...

the spindle is fully formed + chromosomes align in center of cell.

A diploid organism whose somatic (nonsex) cells each contain 32 chromosomes produces gametes containing _____ chromosomes.

16 because it is half of 32.

Normal human gametes carry _____ chromosomes.

23

Meiosis starts with a single diploid cell and produces ___.

4 haploid cells.

How many chromosomes do humans have?

46 22 pairs of autosomes 1 pair of sex chromosomes

In analyzing the karyotype, how could you distinguish trisomy from a chromosome structural defect such as a duplication?

In trisomy there would be one extra chromosome; in a duplication, the number of chromosomes would be normal, but one chromosome would have two copies of a portion of the chromosome.

What name is given to this process?

asexual reproduction

In interphase..

cells are about to divide to replicate their dna. most of cell's life is spent in this phase.

In telophase...

chromosomes become less condensed + nuclear envelopes form.

Meiosis differs from mitosis in that _____ only occurs in meiosis.

crossing over.

What is trisomy?

An extra copy of a chromosome that results in a chromosomal condition.

Which of these cells is (are) haploid?

C and D. Once meiosis I is completed, cells are haploid.

During binary fission, each copy of the duplicating chromosome moves to opposite ends of the cell. What does this achieve?

The separation of the duplicating chromosomes ensures that each daughter cell receives a chromosome.

Which of the following processes depends on the formation of vesicles?

cytokinesis in a plant cell

You can determine this is a plant cell rather than an animal cell because it has __________.

formed a cell plate

During prophase I of meiosis,

homologous chromosomes stick together in pairs.

Chromatids are ___.

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

A cell preparing to undergo meiosis duplicates its chromosomes during ___.

interphase.

When we say that an organism is haploid, we mean that _____.

its cells have one set of chromosomes.

Gametes are produced by ...

meiosis, it produces haploid gametes from a diploid parental cell.

Variation occurs when chromosomes are shuffled in _____.

meiosis.

In prophase...

microtubules form the mitotic spindle + nuclear envelope breaks up.

What is a karyotype?

picture of all of a person's chromosomes

During what phase of meiosis does recombination occur?

prophase I

The correct order of events during meiosis is

prophase I, metaphase I, anaphase I, telophase I, cytokinesis, meiosis II.

In the telophase of mitosis, the mitotic spindle breaks down and the chromatin uncoils. This is essentially the opposite of what happens in _____.

prophase.

In anaphase..

sister chromatids separate + become chromosomes that move to opposite sides of the pole.