EASY POINTS! In peas, long stem (A) is dominant over short stem (a). A heterozygous, long stem plant (Aa) is crossed with a homo-zygous, short stemmed plant (aa).

Which of the above squares represent plants that are heterozygous?

Question 9 options:

Box 1

Box 1 and box 2

Box 1 and box 3

Box 2 and box 3

It is the physical appearance of the trait, whether the plant has Long stem or short stem.

A genotype refers to the genetic characteristics of an organism's trait, if it is heterozygous or h o m o-zygous, recessive or dominant. This question is basically based on the Genotype, asking for the heterozygous plants which is a genotypic characteristic.

Allele Long stem A is dominant over short stem a

Pea Plant 1 has genotype Aa

Pea Plant 2 has genotype aa

The question asks for how many heterozygous plants are present in the punnet square of pea plant 1 and pea plant 2.

Heterozygous Plants means those plants which have two different alleles that means One dominant allele (i.e. A here) and One recessive allele (i.e. a here). These Organisms inherit a different version from each parent. In a heterozygous genotype, the dominant allele overrules the recessive one.

If we look at the punnet square given in the attachment, the Box 1 and 3 have genotype Aa which is a HETEROZYGOUS DOMINANT PLANT while box 2 and 4 have a genotype aa which is a HOMO-ZYGOUS RECESSIVE PLANT thus the answer is Box 1 and 3