Question

Match the columns and choose the correct option:

	Column I		Column II
a.	Dominance	i.	Many genes govern a single character
b.	Codominance	ii.	In a heterozygous organism only one alleles expresses itself
c.	Pleiotropy	iii.	In a heterozygous organism both alleles expressed themselves fully
d.	Polygenic inheritance	iv.	A single gene influences many characters

A) (ii), (i), (iv), (iii)
B) (ii), (iii), (iv), (i)
C) (iv), (i), (ii), (iii)
D) (iv), (iii), (i), (ii)

Answer 1

Hint: The essential foundations of genetics are genes and genotypes. A specific form of a gene is an allele and it is transmitted from parents to their offspring. The fusion of two alleles, one obtained from each parent, is a genotype.

Complete Answer:
Inheritance is the method of transferring genetic material from parent to offspring. That is why close family members appear to have identical characteristics.
Now, let us find the solution from the options-
- Dominance is the concept of masking one version (allele) of a gene on a chromosome or overcoming the impact on the other variant of the chromosome of a separate variant of the same gene. The first variant is called dominant and recessive the second. This condition of having on each chromosome two separate versions of the same gene is typically caused by a mutation, whether new (de novo) or hereditary, in one of the genes.

- Incomplete dominance is closely linked to codominance, where all alleles are expressed equally in the heterozygote. Codominance is a relation between a gene's two copies. Individuals obtain from each parent one variant of a gene, called an allele. The dominant allele will usually be displayed if the alleles are distinct, while the influence of the other allele, named the recessive allele, is hidden. However, no allele is recessive in codominance, and the phenotypes of both alleles are displayed.

- Pleiotropy develops when two or more apparently unrelated phenotypic features are affected by one chromosome. A pleiotropic gene is considered a gene that exhibits several phenotypic features.
- In Polygenic inheritance, a single character is regulated by multiple genes.

Thus, the correct answer is option (B) (ii), (iii), (iv), (i).

Note: A genotype's physical appearance is called the phenotype. The physical appearance (the phenotype) of the physical characteristic for which the alleles bear information is influenced by the particular mixture of the two alleles (the genotype). The phenotype could also be affected by the environment.