Question

A plant has 2n = 16. Which of the following statements is TRUE?

1) n = 4
2) n = 8
3) n = 12
4) n = 16

Answer 1

In a plant with 2n = 16, the haploid number 'n' equals 8. For four-o'clock flowers, crossing true-breeding red (RR) with white (rr) plants results in pink offspring with a heterozygous genotype (Rr).

Step-by-step explanation:

The question pertains to the concept of chromosome numbers and inheritance in plant reproduction. Since the plant has 2n = 16, the correct statement is that n = 8. This is because the letter 'n' represents the number of chromosomes in a haploid set. So, if the diploid number (2n) is 16, then the haploid number 'n' should be half of 16, which is 8.

In the case of the four-o' clock flowers, if a red-flowered plant (RR) is crossed with a white-flowered plant (rr), all offspring would be pink. This indicates incomplete dominance, where the heterozygous genotype (Rr) results in a pink phenotype. So, the correct genotype for the pink-flowered offspring would be Rr.

Considering these concepts, the correct answer to the student's question would neither be 64 genotypes nor 16 phenotypes, but relates to the genotype Rr for the four-o'clock flowers offspring resulting from a cross between RR and rr parent plants.