Question

Study the following and choose the correct statements.

• Cumulative effect of two or more genes on a single phenotypic trait is known as polygenic inheritance.
• Karyotype of Turner syndrome is AA+XXY.
• The longest gene codes for the muscle protein dystrophin.
• Highest number of genes are located in 21^st chromosome.

• A. I, II
• B. III, IV
• C. I, III
• D. II, IV

Hint:

Remember: \[ \boxed{ \begin{aligned} &\text{Polygenic inheritance} &&\rightarrow \text{Many genes control one trait} &\text{Turner syndrome} &&\rightarrow 45,X &\text{Longest human gene} &&\rightarrow \text{Dystrophin} &\text{Chromosome 21} &&\rightarrow \text{Fewest genes} \end{aligned} } \]

Answer 1

The Correct Option is C

Step 1: Evaluate each statement. \[ \begin{aligned} I. &\text{True} &&\text{Polygenic inheritance involves cumulative action of multiple genes.} II. &\text{False} &&\text{Turner syndrome has karyotype }45,X\;(\text{AA}+XO),\text{ not AA+XXY.} III. &\text{True} &&\text{Dystrophin gene is the longest known human gene.} IV. &\text{False} &&\text{Chromosome 21 contains the fewest genes, not the highest number.} \end{aligned} \]

Step 2: Identify the correct statements. \[ \boxed{\text{I and III}} \]

Step 3: Choose the correct option. Hence, \[ \boxed{(C)} \] is the correct answer.