Question

Which of the following represent a pair of contrasting characters?
(a) Homozygous
(b) Heterozygous
(c) Allelomorphs
(d) Codominant genes

Answer 1

Hint: Contrasting characters are the pair of characters that are exhibited by two different characters. The concept of contrasting characters was exhibited by the pea plant for the study of genetics.

Complete answer:
Allelomorphs represent the pair of contrasting characters. Allelomorph is defined as the occurrence of one or more than one gene alternatively at the given site on a chromosome which occurs in pairs and affects the expressions of a particular character. An allele is a form of a gene that is sometimes located at the same position or the genetic locus on a chromosome. Diploid organisms consist of two alleles which are presented at each genetic locus and one allele inherits from each parent. The genotype of a specific gene is represented by each pair of alleles and the allele contributes towards the organism's phenotype which is defined as the outward appearance of an organism.

Additional information:
Homozygous: Homozygous is defined as the genetic condition under which the individual has inherited the same DNA sequence for a particular gene from their biological mother and father which is used in the context of diseases. Homozygous consists of the copy of the same allele that codes for a particular trait and contains only one type of allele which can be dominant or recessive. Self-fertilization takes place in homozygous traits and only one type of gamete is produced.
Heterozygous: Heterozygous condition is defined as when there are two different copies of alleles that code for a particular trait and consist of different alleles for a trait that is both dominant and recessive. Self-fertilization takes place in heterozygous terms which results in the different combination of traits over generations and two types of gametes are produced which can show either complete dominance or incomplete dominance.
Codominant genes: Codominant genes are defined as the condition of the genes where one allele cannot mask the expression of another allele and an individual organism inherits the allele from their mother and father.

So, the correct answer is 'Allelomorphs'.

Note:
William Bateson gives the term allele which is used to describe different forms of genes. The alleles which consist of low penetrance and the effect of them are not manifested in a mendelian pattern of inheritance are known as risk alleles.