Define lethal allele

Define multiple allelism.

Define Lethal genes.

What are lethal alleles ? Give example.

In which palnt was a lethal allele reported for the first time …………

Define alleles.

A collection of all the alleles of all the genes of a crop plant is called

Assertion : ABO blood group system provides a good example of multiple alleles Reason : In ABO blood group system, when I^(A) and I^(B) alleles are present together, they both express their own types

Assertion (A): Monohybrid inheritance is the inheritance of a single character. Reason (R ) : It involves the inheritance of single allele of a single gene.

Three copies of chromosome-21 in a child with Down's syndrome have been analysed using molecular biology technology to detect any possible DNA polymorphism with reference to different alleles located onchromosome-2 1. Results showed that out of 3 copies 2 of the chromosomes of the child contain the same alleles ,as one of the mother's alleles. Based on this when did the non-disjunction event most likely occur?