Class 10 (Science Assignment)

 

Heredity

Heredity is the process by which traits are passed from parents to their offspring. These traits may include eye color, hair type, skin color, blood group, and many other characteristics. The basic units of heredity are called genes. Genes are found on structures called chromosomes, which are located in the nucleus of a cell.

Humans have 46 chromosomes arranged in 23 pairs. One chromosome of each pair is inherited from the mother and the other from the father. During reproduction, the parents produce special cells called gametes. The fusion of a male gamete (sperm) and a female gamete (ovum) forms a zygote, which develops into a new individual.

Not all inherited traits appear in the same way. Some traits are dominant, while others are recessive. A dominant trait is expressed when at least one dominant gene is present, whereas a recessive trait appears only when both genes are recessive. For example, in pea plants studied by Gregor Mendel, the gene for tallness is dominant over the gene for dwarfness.

Heredity creates both similarities and variations among individuals. Children resemble their parents because they inherit genes from them, but they are not exactly the same because each offspring receives a unique combination of genes. These variations help organisms adapt to changing environments and play an important role in evolution.

Understanding heredity helps scientists study inherited diseases, improve crop varieties, and develop better methods of animal breeding. Therefore, heredity is an important branch of genetics that explains how characteristics are transmitted from one generation to the next.

Short Questions

1.     What is heredity?

2.     What are genes?

3.     Where are chromosomes found in a cell?

4.     How many chromosomes are present in a human body cell?

5.     What are gametes? Name the male and female gametes in humans.

6.     What is a zygote? How is it formed?

7.     Differentiate between dominant and recessive traits with one example.

8.     Who is known as the Father of Genetics?

9.     Why do children resemble their parents but are not exactly identical to them?

10.  Mention any two practical applications of the study of heredity or genetics.