What is heterozygouz?

Answer 1

Many organisms contain two copies of each chromosome, and generally these two chromosomes are not identical. If a particular trait, such as the shape of a pea, is determined by one particular section of a chromosome, it is possible for the two copies of the chromosome to have different instructions for the trait. If the two sections of the two chromosomes have different instructions, this is called being heterozygous.

Often if an organism is heterozygous for a trait, one of the sets of instructions (called an allele) will be dominant over the other. This means that if either of the chromosomes has that dominant version of the allele, that is the set of instructions that will be followed.

Examples: The gene for seed shape in pea plants exists in two forms, one form or allele for round seed shape (R) and the other for wrinkled seed shape (r). A heterozygous plant would contain the following alleles for seed shape: (Rr).

Organisms have two alleles for each trait. When the alleles of a pair are heterozygous, one is dominant and the other is recessive. Using the previous example, round seed shape (R) is dominant and wrinkled seed shape (r) is recessive. Round: (RR) or (Rr), Wrinkled: (rr).