Q16)Read the following and answer any four questions from 16(i) to 16(v) given below:

Some human characteristics, such as height, eye color, and hair color, don’t come in just a few distinct forms. Instead, they vary in small gradations, forming a spectrum or continuum of possible phenotypes. Features like these are called quantitative characters, and they’re typically controlled by multiple genes (often, many genes), each of which contributes to the overall phenotype. For example, although there are two major eye color genes, there are at least 14 additional genes that play roles in determining a person’s exact eye color.

i. In Polygenic inheritance, traits are determined by:
a. Multiple alleles at a single locus b. The interaction of multiple genes c. Two dominant alleles on a gene d. One gene being masked by another

ii. How many different allele combinations can possibly be produced from two parents that are heterozygous for a polygenic trait controlled by three different genes with two allele pairs?
a. 5 b. 7 c. 54 d. 64

iii. Cumulative effect of inheritance is noticed in ______
a. ability to dance b. intelligence in human beings c. locomotion in animals d. number of flowers in plants

iv. Each gene has a certain amount of effect. The more is the number of dominant genes, the greater will be ______
a. the expression of symptoms b. the expression of mobility c. the expression of the character d. number of progenies

v.The following statements are drawn as conclusions from the above data:
1. Out of the 100 students 40 students are with an average height of 69 inches and they possess maximum number of dominant genes for the height.
II.40% of the high school students have similar height due to the similarity of gene expression for the Height.
III. Out of the 100 students 70 students are with medium height between 67 to 71 inches.
IV. Height of 20% of the students is72 inches

Choose from below the correct statement which shows relation between height and polygenic inheritance
a. only I b. I and II c. III and II d. I and III

Dear Student,

The solutions to your 1st and 2nd queries have been provided below:

i. Polygenic traits are determined by interactions between many genes that exhibit incomplete dominance.

Therefore, the correct option is b.

ii.  Each parent can produce eight different allele combinations (ABC, ABc, AbC, aBC, Abc, aBc, abC, abc), resulting in a total of 64 combinations when two parents are combined.

Therefore, the correct option is d.

For the remaining queries, we request you to post them in separate threads to have rapid assistance from our experts.


Regards,

  • 0
What are you looking for?