Final answer:
An allotetraploid derived from Species A (2n=12) and Species B (2n=14) will have 26 chromosomes, as each species contributes two sets of chromosomes. The correct answer is option b) 26.
Step-by-step explanation:
The question at hand involves understanding how chromosome numbers are affected in allopolyploid organisms. Species A and species B are closely related diploid species with different chromosome numbers. Species A has 2n = 12 chromosomes and Species B has 2n = 14 chromosomes. An allopolyploid is an organism that contains two or more sets of chromosomes from two different species. A tetraploid has four sets of chromosomes, hence the prefix 'tetra' which means four.
To determine the number of chromosomes in an allotetraploid derived from these two species, we double the diploid number of each species because a tetraploid would have four sets of chromosomes. Therefore, for Species A (2n = 12), there would be 24 chromosomes, and for Species B (2n = 14), there would be 28 chromosomes. Adding these two numbers together gives us the total chromosome count for the allotetraploid: 24 + 28 = 52.
However, this number must be halved to account for the fact that each species contributes two sets of chromosomes each in the allotetraploid, not four. So the correct final chromosome count is 52 / 2 = 26. Thus, the correct answer to how many chromosomes an allotetraploid will have is 26 (Option b).