Answer:
Option 3, 20 or 22
Explanation:
A newly discovered species of dung beetle has 2n = 16 chromosomes. It mates with a closely related beetle species that has 2n = 12 chromosomes. How many chromosomes would there be in an allotriploid beetle produced from this cross?
- 40 or 44
- 20 or 22
- 20 or 22
- 36 or 48
- 40 or 44
Solution
An allotriploid is a species which contains three sets of chromosomes of different species .Crossing can result in triploid offspring with diploid gamete of one species and regular haploid gamete of other offspring
Case I - Resulting offspring (3n) = Gamete I (2n) + Gamete II (n)
OR
Case II - Resulting offspring (3n) = Gamete II (2n) + Gamete I (n)
Case I
Case II
Hence, option 3 is correct