Cell Cycle and Chromosomes

47, XX,+16 is a chromosomal abnormality in which there are three copies of chromosome 16 rather than two. It is the most common chromosomal cause of miscarriage during the first trimester of pregnancy. It is impossible for an infant to take birth with an extra copy of this chromosome present in all cells.

It is the correct statement that it is associated with methylation of cytosines 5' to guanosines.

Down's syndrome is an example of trisomy in chromosome 21.

Ovum has one One X chromosomes.  Ovum of human does not have Z- Chromosome.

Spermatids are the product of the final meiotic division. They undergo an elaborate process of maturation,  i.e. spermiogenesis to become spermatozoa.

Gametes are haploid cells (n) containing half the DNA of somatic cells. Parent body cells are diploid (2n) with twice the DNA content. Therefore, the ratio of gamete DNA to parent cell DNA is 1:2.

It is false because some cells like red blood cells or nerve cells cannot repair themselves or multiply themselves but most cells like skin cells can.

In a dividing cell, the chromatin material forms small thread like structures called chromosomes.

Yes, it is correct. It is present in the female's uterus and helps in baby's protection and growth. To check the abnormality in chromosomes, amniotic fluid is used.

Yes, it is correct. The chromosomal pattern of the amniotic fluid determines the sex of a foetus.

Mendel's 'factors' are the discrete units of heredity he proposed, which were later discovered to be genes - segments of DNA that code for specific traits. Chromosomes and DNA are the structures that contain genes, while genes are the functional units.

A gene is a specific region of DNA that contains the instructions for a particular hereditary characteristic. While chromosomes contain many genes and chromatin is the DNA-protein complex, the gene is the functional unit that controls specific traits.

Human males have one X chromosome from the mother and one Y chromosome from the father, resulting in XY sex chromosomes. Females have two X chromosomes (XX). The Y chromosome determines male development.

Human cells have 23 pairs of chromosomes, including 1 pair of sex chromosomes (either XX in females or XY in males). The other 22 pairs are autosomes that carry most genetic information.

Human somatic cells contain 46 chromosomes (23 pairs), while gametes (sperm and egg) have 23 chromosomes. This diploid number (2n=46) is characteristic of human cells.