Mastering Genetics Chapter 2 HW

Cells that are metabolically active, but not destined to proliferate are said to be in _______.

G0 phase

When cells withdraw from the continuous cell cycle and enter a "quiescent" phase, they are said to be in what phase?

G0 phase

DNA content per cell doubled in all phases except

G1

The_____ is a cell structure consisting of microtubles, which forms during early mitosis and plays a role in cell division.

mitotic spindle(s)

How many haploid set(s) of chromosomes are present in a diploid individual cell with a chromosome number of 32?

2 set(s)

How many haploid set(s) of chromosomes are present in a diploid individual cell with a chromosome number of 46?

2 set(s)

The house fly, Musca domestica, has a haploid chromosome number of 6. How many chromatids should be present in a diploid, somatic, metaphase cell?

24 chromatids

How many haploid sets of chromosomes are present in an individual cell that is tetraploid (4n)?

4 set(s)

When do sister chromatids separate during meiosis?

Anaphase II

The parent cell that enters meiosis is diploid, whereas the four daughter cells that result are haploid. Which statement correctly describes how cellular DNA content and ploidy levels change during meiosis I and meiosis II?

B.) A.) DNA content is halved only in meiosis I. Ploidy level changes from diploid to haploid in meiosis I, and remains haploid in meiosis II. B.) DNA content is halved in both meiosis I and meiosis II. Ploidy level changes from diploid to haploid in meiosis I, and remains haploid in meiosis II. C.) DNA content is halved only in meiosis II. Ploidy level changes from diploid to haploid in meiosis I, and remains haploid in meiosis II. D.) DNA content is halved in both meiosis I and meiosis II. Ploidy level changes from diploid to haploid only in meiosis II. E.) DNA content is halved only in meiosis I. Ploidy level changes from diploid to haploid only in meiosis II.

Which structure is not found in all mitotic cells?

Centriole

Each of the following events occurs during mitosis except _______.

D.) A.) nuclear membrane breaks down B.) microtubules assemble between centrioles C.) chromosomes condense D.) polar microtubules contract, pulling attached chromosomes toward the poles

During interphase of the cell cycle, _______

DNA content essentially doubles

Haploid cells do not undergo mitosis

False

The cell cycle consists of a shorter phase called interphase and a longer phase called mitosis, during which cell division takes place

False

Which list of steps in the eukaryotic cell cycle is given in the correct order?

G1 - S - G2 - M - G1 .

From which phase of the cell cycle does a cell enter G0 phase?

G1 phase

If two chromosomes of a species are the same length and have similar centromere placements and yet are not homologous, what is different about them?

Genetic content, the pattern and time of replication during S phase.

Two terms, reductional and equational, generally refer to which stages of meiosis (I or II)?

Meiosis I is reductional; meiosis II is equational.

During which stage of prophase I does crossing over take place?

Pachynema

Sister chromatids are present in

S phase' G2 phase, beginning of M phase

What is the arrangement of chromosomes during metaphase?

Sister chromatids are aligned along the equatorial plane of the cell.

You are given a metaphase chromosome preparation (a slide) from an unknown organism that contains 12 chromosomes. Two that are clearly smaller than the rest appear identical in length and centromere placement. What would most likely be true of these two chromosomes? Select all that apply.

They have similar banding patterns. They would replicate synchronously during the S phase of the cell cycle. They are homologous chromosomes.

DNA is condensed in

Throughout M phase

A tetrad is composed of one pair of homologous chromosomes at synapsis of prophase I.

True

If a typical G1 nucleus contains 2C (two complements) of DNA, a gamete that is haploid (n) contains 1C of DNA

True

S phase is the part of interphase when DNA duplication takes place.

True

The end result of meiosis is four haploid daughter cells.

True

The meiotic cell cycle involves two cell divisions but only one DNA replication.

True

A __________ chromosome has its centromere located very close to, but not on, the end of the chromosome.

acrocentric

When do sister chromatids separate during meiosis?

anaphase II

Separation of sister chromatids occurs _______.

at anaphase in mitosis and anaphase II in meiosis

After chromosomes condense, the ____is the region where the identical DNA molecules are most tightly attached to each other

centromere(s)

The_____ are the organizing centers for microtubules involved in separating chromosomes during mitosis.

centrosome(s)

Name two cellular organelles, each having genetic material, that are involved in either photosynthesis or respiration.

chloroplasts & mitochondria

During interphase, most of the nucleus is filled with complex DNA and protein in a dispersed from called____.

chromatin

During telophase, the nonkinetochore microtubules___

disassemble

In dividing cells, most of the cell's growth occurs during _____.

interphase

During mitosis, microtubles attach to chromosomes at the _____.

kinetochore(s)

During prophase, the microtubules of the miotic spindle ____

lengthen

During anaphase, the nonkinetochore microtubules_____ and move past each other, and the kinetochore microtubules ____

lengthen; shorten

Novel combinations of genes can arise from _______.

reciprocal exchange of DNA between homologs during prophase I

Which of the following cell structures is directly involved in protein synthesis?

rough endoplasmic reticulum and ribosomes

DNA replication produces two identical DNA molecules, called _____, which separate during mitosis.

sister chromatid(s)

Consider an animal cell in which motor proteins in the kinetochores normally pull the chromosomes along the kinetochore microtubules during mitosis. Suppose, however, that during metaphase, this cell was treated with an inhibitor that blocks the function of the motor proteins in the kinetochore, but allows the kinetochore to remain attached to the spindle. The inhibitor has no effect on any other mitotic process, including the function of the nonkinetochore microtubules. Will this cell elongate during mitosis? (yes or no?) Will the sister chromatids separate from each other? (yes or no?) Will the chromosomes move to the poles of the cell? (yes or no?)

yes,yes,no