Question

Select the group of CORRECT statements.
I. If phenotype of offsprings shows only the dominant trait then the parent plants are heterozygous.
II. A true breeding line shows stable trait inheritance and expression for several generations.
III. In mendelian experiment material, contrasting characters can be easily recognized.
IV. When a single gene controls two (or more) different traits, it is called polygene.
V. When interactions occur between the alleles of different genes present on the same or different chromosome it is called intragenic interaction.

• A. III and V only
• B. II and III only
• C. III and IV only
• D. I and V only

Hint:

Check each statement against the definitions of dominance, true breeding, pleiotropy and intergenic interaction.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept
Each statement is tested one by one.

Step 2: Statements
I is wrong because offspring showing only the dominant trait can also come from homozygous dominant parents.
II is correct. A true breeding line shows stable inheritance for many generations.
III is correct. Contrasting characters in Mendel's material are easy to recognise.

Step 3: Remaining
IV is wrong because a single gene controlling many traits is pleiotropy, not polygene.
V is wrong because interaction between alleles of different genes is intergenic.

Step 4: Match
Correct statements are II and III only, option (B).

Final Answer:
Statements II and III are correct. \[ \boxed{\text{(B) }\text{II and III only}} \]