Question

All female population of fish seed can be produced by

• A. Androgenesis
• B. By using methyl testosterone
• C. Gynogenesis
• D. Triploidy

Hint:

- Gynogenesis \(\rightarrow\) All-female population (\(100\%\) maternal inheritance).
- Androgenesis \(\rightarrow\) All-male population (\(100\%\) paternal inheritance).
- Triploidy \(\rightarrow\) Sterile fish (three sets of chromosomes).

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Monosex populations are highly desirable in species where one sex grows faster, matures later, or exhibits better market traits than the other.

Step 2: Detailed Explanation:
- Gynogenesis is a form of chromosome manipulation where the genetic material of the male (sperm) is completely inactivated (usually via UV or gamma irradiation), but the sperm is still allowed to penetrate the egg to activate development.
- Since the paternal genome is destroyed, the offspring inherit chromosomes exclusively from the mother.
- Diploidy is restored in the developing zygote by applying a temperature or pressure shock to block the first polar body release or first cleavage.
- Because the chromosomes are entirely of maternal origin, \(100\%\) of the resulting progeny are female.
- Androgenesis produces all-male populations, and Methyltestosterone is a hormone used for masculinization (direct sex reversal).

Step 3: Final Answer:
An all-female population of fish seed can be produced by gynogenesis, which corresponds to option (C).