Question

Gregor Mendal in examining tea-plants found two sharply marked races, the tall and the short. He experimentally fertilized flowers of tall plants with pollen of short. The offspring were tall plants. He next let the flowers of this first generation be fertilized with their own pollen. In the following generation, shortness reappeared. Tallness and shortness were distributed not at random but in a definite, constant, and simple ratio: three dominant talls to one recessive short. Which one of the following aptly describes the distribution of dominant and recessive characteristics?

• A. Systematic
• B. equal interval
• C. unpredictable
• D. irregular interval

Hint:

Whenever a question invokes Mendel’s $3:1$ or $1:2:1$ ratios, the key idea is a {regular} (systematic) distribution, not randomness.

Answer 1

The Correct Option is A

Step 1: Read the empirical pattern. The traits appear in a fixed, constant ratio (3:1) in F$_2$.
Step 2: Map to labels. A fixed, law-like split is {systematic}, not “equal interval” (a numerical spacing term), not “unpredictable,” and not “irregular.” Hence \(\boxed{\text{Systematic}}\).