With reference to principles of genetics and cell division, consider the following statements:
1. In incomplete dominance, the phenotypic ratio in the generation is identical to its genotypic ratio ().
2. Recombination nodules appear during the Pachytene substage of Prophase I in meiosis, where crossing over occurs via the enzyme recombinase.
3. Haemophilia is an X-linked recessive genetic trait that is transmitted directly from an affected father to his sons.
Which of the statements given above are correct?
- 1 and 2 onlyAnswer
- B2 and 3 only
- C1 and 3 only
- D1, 2 and 3
Answer
The statement option asserting that 1 and 2 only are correct represents the accurate answer.
Incomplete dominance alters the standard 3:1 Mendelian phenotypic ratio to 1:2:1, making it identical to the genotypic ratio. Furthermore, recombination occurs during Pachytene of Meiosis I facilitated by recombinase. Haemophilia is X-linked, making direct father-to-son transmission genetically impossible because sons inherit only the father's Y chromosome.
Step-by-Step Solution
Key Concept
Non-Mendelian Inheritance, Meiotic Crossing Over, and Sex-Linked Inheritance Patterns
Estimated Time:2m 0s