Cell Cycle

During _____ a spindle forms in a haploid cell.

Prophase II

The second division of meiosis

prevents a doubling of chromosome copies at fertilization.

Which of the following organisms would be most similar to humans in a study that involved the response of cancer cells to various medications?

primates

Spindle fibers attach to kinetochores during _____.

prometaphase

Which processes lead to most genetic variation in sexually reproducing organisms?

random fertilization crossing over independent assortment of chromosomes in meiosis

Which of the following occurs during S phase?

replication of the DNA

At the milestone that defines anaphase, the chromosomes

separate

Meiosis II is similar to mitosis in that

sister chromatids separate during anaphase

Cytokinesis often, but not always, accompanies _____.

telophase

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

Which of these cells is (are) haploid?

Meiosis I and Meiosis II

Synapsis occurs during _____.

Prophase I

During meiosis I in humans, one of the daughter cell receives

a mixture of maternal and paternal chromosomes

Through a microscope, you can see a cell plate beginning to develop across the middle of a cell and nuclei forming on either side of the cell plate. This cell is most likely

a plant cell in the process of cytokinesis.

A human cell containing 22 autosomes and a Y chromosome is

a sperm.

Centromeres divide and sister chromatids become full-fledged chromosomes during _____.

anaphase

During _____ sister chromatids separate.

anaphase II

During meiosis, the sister chromatids separate during

anaphase II

At the milestone that defines telophase, the chromosomes

are at opposite poles

The members of a homologous pair of chromosomes

are identical in size and appearance

Since 1991, deaths from breast and colorectal cancer in the United States are down 35%. What is the main reason for this?

better screening

Based on the information in the video, which of the following correctly answers these three questions: What was the leading cause of death in the United States in the early 1970s? What is the leading cause of death in the United States today? What is predicted to be the leading cause of death in the United States 10 years from now?

cancer; cardiovascular disease; cancer

Which of the following statements best describes homologous chromosomes?

carry information for the same trait

In plant cells, cytokinesis is accomplished by the formation of a(n)

cell plate

The total DNA content of each daughter cell is reduced during meiosis because

chromosomes do not replicate between meiosis I and II

Which of these is NOT a carcinogen?

cigarette smoke testosterone UV light fat ALL OF THE ABOVE

One difference between cancer cells and normal cells is that cancer cells

continue to divide even when they are tightly packed together.

After the centromeres separate during mitosis, the chromatids, now called _____ move toward opposite poles of the spindle.

daughter chromosomes

All zygotes are

diploid

Vinblastine is a standard chemotherapeutic drug used to treat cancer. Because it interferes with the assembly of microtubules, its effectiveness must be related to

disruption of mitotic spindle formation.

Chromatin condenses to form discrete, visible chromosomes

during prophase

Chromosomes become visible during _____.

prophase

The number of daughter chromosomes in human cell (diploid 46) in anaphase II of meiosis is

46

Diploid cells of the fruit fly Drosophila have ten chromosomes. How many chromosomes does a Drosophila gametes have?

5

Which of the following is closest to the current average annual death rate from cancer in the United States?

580 thousand

If the DNA content of a diploid cell in the G1 phase of the cell cycle is x, then the DNA content of the same cell at metaphase of meiosis I will be

2x

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

16

When did the United States declare a "war on cancer" by passing the National Cancer Act?

1971

In human gamete production there is an average of _____ crossover events per chromosome pair.

2-3

Normal human gametes carry _____ chromosomes.

23

Homologous chromosomes migrate to opposite poles during _____.

Anaphase I

The molecules that make up a chromosome are _____ and _______

DNA; proteins

_____ is a carcinogen that promotes colon cancer.

Fat

Which of the following best describes the advantages of the personalized care technique described in the video?

Fruit flies make excellent models because we can create a strain of flies with a specific type of tumor, then raise thousands of flies in order to test the effects of medications.

Cell A has half as much DNA as cells B, C, and D in a mitotically active tissue. Cell A is most likely in

G1

During _____ chromosomes align single file along the equator of a haploid cell.

Metaphase II

Which of these phases encompasses all of the stages of mitosis but no other events?

Mitosis

Which of the following does not occur during mitotic prometaphase

Synapsis of homologous chromosomes

How does a nucleus in G2 differ from a nucleus in G1

The G2 nucleus has twice the amount of DNA as the G1 nucleus

A bacterial cell gives rise to two genetically identical daughter cells by a process known as

fission

Meiosis II typically produces _____ cells, each of which is _____.

four ... haploid

During mitotic anaphase, chromosomes migrate

from the equatorial plate toward the poles

Meiosis can occur

in all sexually reproducing organisms

During _____ the cell grows and replicates both its organelles and its chromosomes.

interphase

Nucleoli are present during _____.

interphase

The process of synapsis and the formation of chiasmata

involve reciprocal exchange of chromosomal sections involve the recombination of DNA on homologous chromosomes bring about an increase in genetic variation provide evidence that an exchange of genetic material has occured ALL OF THE ABOVE

Which of the following statements about the human X chromosomes is correct?

is present in every gametic cell of males and females

At the milestone that defines metaphase, the chromosomes

line up at the equatorial plate

Human gametes are produced by _____.

meiosis

The two homologs of a pair move toward opposite poles of a dividing cell during

meiosis I.

Homologous pairs of chromosomes are lined up independently of other such pairs during _____.

metaphase I

The mitotic spindle is composed of

microtubules

Crossing over, resulting in an increase in genetic variation, occurs between _____.

nonsister chromatids of homologous chromosomes

The decline of MPF activity at the end of mitosis is due to

the degradation of cyclin.

Why is the "personalized care" plan described in the video, in which treatments are tailored for each individual, much more promising than previous treatment plans?

the genetic mutations that cause cancer vary from patient to patient

During _____ both the contents of the nucleus and the cytoplasm are divided.

the mitotic phase

Meiosis I produces _____ cells, each of which is _____.

two ... haploid

At the end of the first meiotic division, each chromosome consists of

two chromatids

The products of mitosis are

two genetically identical nuclei

If the DNA content of a diploid cell is x in the G1 phase of the cell cycle and 2x at metaphase of meiosis I, then the DNA content of the same cell at metaphase of meiosis II will be

x