chromosomes and genes

Question 1

how is the sex of a baby determined

Answer 1

By the chromosomes that the father contributes. It is the sex chromosomes that are important in determining an individual’s biological sex (whether they are male or female). Human females possess a pair of X chromosomes (XX) and human males possess an X chromosome and a Y chromosome (XY).

Question 2

location of chromosome

Answer 2

the nucleus of cells

Question 3

genes roles

Answer 3

Genes are regions of DNA along a chromosome that code for specific traits (the production of specific proteins). The sequence of bases vary from one gene to another.

Question 4

autosomes

Answer 4

The autosomes are assigned numbers from 1 to 22 on the basis of their size: chromosome 1 being the largest of the autosomes and chromosome 22 the smallest. The two members of a matching pair of chromosomes are described as homologous.

Question 5

nucleotides (somatic cells)

Answer 5

Somatic cells (body cells) are cells of the body that are not sex cells.

Question 6

sex cells

Answer 6

Gametes (sex cells) are the reproductive cells of the body. In animals, gametes are ova (ovum is the singular form) and sperm. These cells are produced by a type of cell division called meiosis, which results in the chromosome number being halved.

Question 7

chromosome structure

Answer 7

These threads are packaged and condensed with the help of proteins called histones into tightly coiled structures known as chromosomes. Each chromosome contains one molecule of DNA wrapped around many small round proteins called histones.

Question 8

karytypes

Answer 8

Karyotyping involves photographing, then pairing chromosomes and arranging homologous pairs in a special sequence (largest pairs to smallest pairs). One copy of each homologous pair of chromosomes comes from the mother (via an ovum) this chromosome is called a maternal chromosome. The other copy comes originally from dad (via a sperm) and this chromosome is called a paternal chromosome.