Question

In pea full pod(F) is dominant over constricted pod ( f) and round seed (R) is dominant over wrinkled seed(r).in a cross involving parent of unknown genotype and phenotype, the following offspring are obtain: phenotype ------- proportion. Full round ------ 3/8. Full wrinkled ------- 3/8. Constricted round --------- 1/8. Constricted wrinkled -------- 1/8. Detetmined the genotype and phenotype of the parents. (6marks)​

Answer 1

Answer:

(ii) Genotype ratio is 1:2:1, RR : Rr : rr

Phenotype ratio is 3:1, round seeds : wrinkled seeds

(iii) There are two sex chromosomes in human, X and Y. Females have XX chromosomes and males have XY chromosomes.

(iv) Mutation refers to the changes in the nucleotide sequence of DNA which can be inherited.

(v) The number of chromosomes in human beings are 23 pairs, that is 22 pairs of autosomes and one pair of sex chromosome. Thus, the gamete will have 23 chromosomes.