Question

Match the columns and choose the correct options

I	II
a. Dominance	i. Many genes govern a single character.
b. Codominance	ii. In a heterozygous organism only one allele 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. a-iv, b-iii, c-i, d-ii
B. a-ii, b-i, c-iv, d-iii
C. a-ii, b-iii, c-iv, d-i
D. a-iv, b-i, c-ii, d-iii

Answer 1

Hint: Genes in humans are considered to be the basis of the functional and physical unit of heredity. Genes are a sequence of nucleotides present in DNA or RNA. These nucleic acids are responsible for the coding of gene product synthesis or protein synthesis.

Step by step answer:a. Dominance: In Mendelian inheritance and classical genetics, dominance is considered a vital concept. In genetics, dominance is defined as the relationship between two gene alleles. A dominant gene masks or overrides the characteristics of the other gene or allele. The other gene or allele is called the recessive gene. The organism with these kinds of genes showcases the characteristics of the dominant gene over the characteristics of the recessive gene.
b. Codominance: The alleles or genes of a gene pair in a heterozygote express the characteristics of both the genes present. This means there is no dominant or recessive gene and as a result, the phenotype of the offspring is a combination of both the parent’s phenotype. A plant or an animal that has more than one pigment is a great example of the co-dominance trait.
c. Pleiotropy: A pleiotropic gene has the ability to express the traits of two or more unrelated phenotypes. This phenomenon is referred to as pleiotropy.
d. Polygenic inheritance: Polygenic inheritance can be observed in humans and other organisms. For instance in humans, a polygenic inheritance is their skin colour, eye colour, weight, and height. It means that a single gene or more genes have the ability to influence many characteristics as mentioned earlier (colour, height, weight).
The correct answer is option C, i.e., a-ii, b-iii, c-iv, d-i

Note: Scientists in South Korea had claimed to have successfully cloned an embryo of a human in 1998 with the employment of genetic engineering. Genetic engineering is considered the direct manipulation of the genes of an organism with the help of biotechnology. But this experiment was interrupted while the clone was just a group of four cells. Similarly, back in 1996, Scottish scientists and researchers were able to clone a lamb from the somatic cells of a six-year-old sheep by the nuclear transfer process after almost 276 attempts. This lamb was named Dolly. She continued to live on for 6 years, during which she had developed severe arthritis and progressive lung disease. She was euthanized on 14th February 2003.