Question

Define the following:
(i) Genotype
(ii) phenotype
(iii) Homozygous
(iv) Heterozygous
(v) Allele
(vi) Dominant
(vii) Recessive

Answer 1

(i) Genotype: It is the genetic constitution of an organism that includes all the genes that are inherited from both the parents. For example TT, Tt, and tt are genotypes of organisms with reference to their height.

(ii) Phenotype: It is the observable trait or characteristic of an organism that is the result of genotype. For example, tallness and shortness are phenotypes resulting from different genotypes.

(iii) Homozygous: It is the diploid condition in which the alleles at a given position on a chromosome are identical.

(iv) Heterozygous: It is the diploid condition in which the alleles at a given position on a chromosome are different.

(v) Allele: It is the alternative form of the same given gene with contrasting characteristics.

(vi) Dominant: An allele that is able to express itself over another contrasting trait. For example, tall plants are dominant over short plants.

(vii) Recessive: An allele that is unable to express its effect in the presence of the dominant trait.