Which of the following cells check for during the G2 check point?

a. Growth hormone c. DNA integrity
b. Nutritional status d. Cell size

In mitosis, if a cell has 4 chromosomes in prophase, how many chromosomes will this cell have in metaphase?
a. 64 b. 32 c. 16 d. 8 e. 4

The X and Y chromosomes are considered
a. Homologous chromosomes. c. Nonhomologous chromosomes.
b. Complementary chromosomes. d. Parallel chromosomes.

If a cell has 20 chromosomes in G1, how many chromatids will be present during prophase?
a. 30 b. 20 c. 5 d. 40

During the cell cycle of a eukaryotic cell, each chromosome is replicated to become a chromosome with two chromatids, and then the chromatids are pulled apart to form two separate chromosomes.
a. True b. False

Which of the following statements is incorrect about homologous chromosomes?
a. Homologous chromosomes are similar but not identical
b. Homologous chromosomes have the same size and function
c. Homologous chromosomes contain genes for the same kind of protein products
d. Homologous chromosomes cannot be duplicated

1.c

2.e
3.c
4.d
5.b
6.b

To answer these questions, we need to understand some concepts related to the cell cycle and chromosome behavior.

1. Which of the following cells check for during the G2 check point?

The G2 checkpoint is a crucial stage in the cell cycle where the cell ensures that all preparations for cell division have been completed before entering the M phase. This checkpoint primarily checks for DNA integrity, making sure that the DNA has been accurately replicated during the S phase. Therefore, the correct answer is c. DNA integrity.

2. In mitosis, if a cell has 4 chromosomes in prophase, how many chromosomes will this cell have in metaphase?

Mitosis is a process of cell division in which the chromosomes are duplicated and then divided equally into two daughter cells. During prophase, each chromosome consists of two identical sister chromatids attached at the centromere. In metaphase, the chromosomes align at the equatorial plane of the cell. Since each sister chromatid is considered as one chromosome, the correct answer is e. 4.

3. The X and Y chromosomes are considered

The X and Y chromosomes determine the sex of an individual in most species, including humans. In humans, females have two X chromosomes (XX), while males have one X and one Y chromosome (XY). These X and Y chromosomes are nonhomologous chromosomes because they differ in size and carry different sets of genes. Therefore, the correct answer is c. Nonhomologous chromosomes.

4. If a cell has 20 chromosomes in G1, how many chromatids will be present during prophase?

During prophase, each chromosome consists of two identical sister chromatids, which are formed during the S phase of the cell cycle when the DNA is replicated. Therefore, if a cell has 20 chromosomes in G1, it will have 40 chromatids during prophase. The correct answer is d. 40.

5. During the cell cycle of a eukaryotic cell, each chromosome is replicated to become a chromosome with two chromatids, and then the chromatids are pulled apart to form two separate chromosomes.

This statement is true. During the S phase of the cell cycle, DNA replication occurs, resulting in the formation of two identical sister chromatids connected by a centromere, making them a single chromosome with two chromatids. In the subsequent stages, such as prophase and metaphase, the sister chromatids are separated and pulled apart by the spindle fibers to form two individual chromosomes. So, the correct answer is a. True.

6. Which of the following statements is incorrect about homologous chromosomes?

Homologous chromosomes are pairs of chromosomes that carry the same genes at corresponding loci. They are similar but not identical, as they can have different alleles for the same gene. Therefore, the incorrect statement is b. Homologous chromosomes have the same size and function. In reality, homologous chromosomes can be different in both size and function.