Question

1. Meiosis is critical for which of the following processes

Answer 1

1. The right answer is B. production of egg and sperm cells

Meiosis is a cell division that, alternately with fertilization, plays a key role in sexual reproduction, halving the number of chromosomes in gametes, thereby maintaining the number of chromosomes of the species after fertilization.

2. The interphase is the phase that precedes the M phase where the cell division takes place (in other words, it is the phase that lies between two divisions).

Before mitosis and meiosis, the interphase is identical for both. However, the small difference between them is that during meiosis (division process including two cell divisions) there is a very small interphase between telophase I and prophase II of meiosis, but without DNA replication.

3. The right answer is C. prophase, metaphase, anaphase, telophase

Prophase

Stage of mitosis during which chromatin condenses and chromosomes appear.

Metaphase

Stage of mitosis during which the fusorial fibers attach to the centromere of the duplicated chromosomes and guide them to the equator of the cell.

Anaphase

Stage of mitosis during which the centromeres divide and chromatids are attracted to the opposite poles of the cell by fusorial fibers.

Telophase

Stage of mitosis in which chromatids have reached the poles of the cell. Each of the chromatids is now a complete non-duplicated chromosome. There is formation of two nuclei.

4. The right answer is True.

The comparison of the karyotypes of different cells of the same individual and the cloning experiments, showed that all the cells of the body have the same genetic program. Moreover this genetic program is at the origin of the manufacture of a new individual.

Thus all the cells of the body except the gametes, has the same karyotype as the egg cell from which they are derived by successive divisions. This karyotype still has 23 pairs of 46 chromosomes, and these chromosomes carry exactly the same genetic information. Each chromosome is made up of DNA. DNA is a molecule that can curl up during cell division, making the chromosomes visible.

Answer 2

B.

Both processes have a growth period called interphase, in which a cell replicates its genetic material and organelles in preparation for division. The two cells that result after meiosis I enter meiosis II very quickly, during the brief interphase period, no further DNA replication takes place.

C.

A. True