Question

Q Write the Mendel's laws of inheritance.
Q Discuss the causes of cancer.

Answer 1

Dear student,
Following are the Mendel's laws of inheritance:-

Law of Dominance:-
Characters are controlled by discrete units called factors, which occur in pairs with one member of the pair dominating over the other in a dissimilar pair. This law explains expression of only one of the parental character in F1 generation and expression of both in F2 generation.

Law of Segregation:-

This law states that the two alleles of a pair segregate or separate during gamete formation such that a gamete receives only one of the two factors. In homozygous parents, all gametes produced are similar; while in heterozygous parents, two kinds of gametes are produced in equal proportions.

Law of independent Assortment:-

When two pairs of traits are combined in a hybrid, one pair of character segregates independent of the other pair of character. In a dihybrid cross between two plants having round yellow (RRYY) and wrinkled green seeds (rryy), four types of gametes (RY, Ry, rY, ry) are produced. Each of these segregate independent of each other, each having a frequency of 25% of the total gametes produced.

Causes of cancer are given below:-
1. Carcinogens : e.g. tobacco present in cigarette.

2. Mutation in genetic makeup.

3. Environmental cause: e.g. hazards and chemicals(asbestos, benzene) that are released from various industries in atmosphere.

4. Bacterial and viral infection

Regards