BIO CH. 6 Meiosis

At the end of telophase I and cytokinesis, there are two haploid cells with chromosomes that consist of ___ sister chromatids each.

2

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

2, haploid. At the end of meiosis I there are two haploid cells.

Humans have __ chromosomes, so their eggs contain __ chromosomes.

23, 46.

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

4, haploid. At the end of meiosis II there are typically 4 haploid cells.

Homologous chromosomes migrate to opposite poles during which stage?

Anaphase I. (Homologous)

How is mitotic anaphase different than anaphase II?

Anaphase II is essentially the same as mitotic anaphase except that the cell is haploid.

Which of the following appears to be true according to current research on Helicobacter pylori and esophageal cancer?

As the population of Helicobacter pylori decreases in the human body, cases of esophageal cancer increase. (Helicobacter pylori decreases the risk)

When cells avoid direct contact with other cells in neighboring tissues, this is known as __________.

Contact Inhibition

Do gametes of an individual have the same/different genetic makeup? Do somatic cells?

Gametes-Different. Somatic-Same. Random alignment and crossing over during meiosis ensure that no two gametes produced by an individual will be exactly the same. However, an individual's somatic cells divide by mitosis, which results in the production of cells that are genetically identical to the parent cell.

What codes for proteins?

Genes

What is anchorage dependence?

Healthy cells need to have an anchor in order to survive. Cancer cells do not need an anchor, hence cancer spreads.

When does random assignment occur?

Homologous chromosomes align at the middle of the cell randomly during metaphase I.

During which phase do the centrosome duplicates and the chromosomes are not condensed.

Interphase. (Centrosomes are what's attatched to the spindle fibers)

How is mitotic metaphase different than metaphase II?

Metaphase II is essentially the same as mitotic metaphase except that the cells are haploid

What is the multiple-hit model?

Multiple mutations are required for the development of cancer.

Synapsis, the pairing of homologous chromosomes, occurs during which stage?

Prophase I

Are somatic cells haploid/diploid? Sex cells?

Somatic-Diploid Sex-Haploid

Is cancer caused by a virus?

Some cancers are caused by viruses.

Whats the difference between prophase I and prophase II?

The events of prophase II are essentially the same as those of mitotic prophase except that prophase II cells are haploid.

Haploid cells are produced where?

The gonads. Human haploid eggs are produced in the female's ovaries, while haploid sperm are produced in the male's testes.

What do the terms diploid and haploid refer to?

The number of chromosomes in cells.

What do proto-oncogenes do?

They regulate the cell cycle in healthy cells.