Question

Nuclei in somatic cells of the freshwater alga Draparnaldia plumosa have 13 chromosomes. In the closely related species Draparnaldia acuta, nuclei in somatic cells have 26 chromosomes.

Which of the following is correct:
a. Gametes of Draparnaldia acuta should contain 13 chromosomes.
b. Draparnaldia plumosa zygotes contain 26 chromosomes; meiosis should occur after fertilization.
c. Draparnaldia acuta is a diploid organism; the expected n number for its haploid gametes is 13.
d. Draparnaldia plumosa is a monoploid organism with n = 13.
e. All of the above

Answer 1

b. Draparnaldia plumosa zygotes contain 26 chromosomes; meiosis should occur after fertilization.

Step-by-step explanation:

Draparnaldia plumosa is a freshwater green algae. The thallus of this species is haploid. Each cell of the thallus has 13 chromosomes in its nucleus. During sexual reproduction thallus forms gametes through mitosis. After fertilization between isogametes, a diploid zygote is formed having 26 chromosomes. Zygote undergoes meiosis to form haploid thallus.