A new plant species C, which formed from hybridization of species A(2n = 16) with species B(2n = 12), would probably produce gametes with a chromosome number of
a. 12.
b. 14.
c. 16.
d. 28.

Verified step by step guidance

1. Determine the haploid chromosome number (n) for each parent species. For species A, 2n = 16, so n = 16/2 = 8. For species B, 2n = 12, so n = 12/2 = 6.
2. When hybridization occurs, the resulting hybrid species C will initially have a chromosome number equal to the sum of the haploid numbers of the parent species. Therefore, the initial chromosome number of species C is 8 + 6 = 14.
3. In order for species C to produce viable gametes, it must undergo chromosome doubling (polyploidy) to restore homologous pairing during meiosis. This process results in a new species with a chromosome number of 2 × 14 = 28.
4. The gametes produced by species C will have half the chromosome number of the polyploid individual. Therefore, the gametes will have a chromosome number of 28/2 = 14.
5. Based on this reasoning, the correct answer is the gametes of species C would have a chromosome number of 14.

Key Concepts

Chromosome Number and Gametes

In sexually reproducing organisms, the chromosome number is typically represented as diploid (2n), which includes two sets of chromosomes. Gametes, or sex cells, are produced through meiosis and are haploid (n), containing half the number of chromosomes. Understanding how to derive the haploid number from the diploid number is essential for determining the chromosome count in gametes.

Hybridization and Polyploidy

Hybridization occurs when two different species interbreed, resulting in offspring that may have a combination of traits from both parents. In some cases, hybridization can lead to polyploidy, where the offspring have more than two sets of chromosomes. This concept is crucial for predicting the chromosome number of the new species formed from species A and B.

Calculating Gamete Chromosome Number

To calculate the chromosome number of gametes produced by a hybrid species, one must first determine the diploid number of the hybrid. In this case, species A has 16 chromosomes (2n = 16) and species B has 12 chromosomes (2n = 12). The hybrid species C would likely have a diploid number that is the sum of the two, leading to a haploid number that can be calculated for gamete formation.