[Campbell Biology P.689] Referring to Figure 30.4, identify the correct sequence of events a... | Practice Question

Referring to Figure 30.4, identify the correct sequence of events and associated ploidy changes in the pine life cycle.

  • A: Microsporocytes (2n) undergo mitosis to produce haploid microspores.
  • B: The megaspore (n) develops directly into a new sporophyte (2n).
  • C: Fertilization unites sperm (n) and egg (n) nuclei to form a diploid zygote (2n).
  • D: The mature sporophyte (2n) is produced from the germination of a haploid pollen grain (n).

Explanation

Statement C accurately describes the process of fertilization, where haploid sperm and egg nuclei fuse to form a diploid zygote, as indicated in point 7 and the "FERTILIZATION" box in Figure 30.4. Statement A is incorrect because microsporocytes undergo meiosis point 2 . Statement B is incorrect because the megaspore develops into a haploid female gametophyte point 6 before fertilization. Statement D is incorrect because the mature sporophyte develops from the diploid embryo within the seed point 8 , not from a haploid pollen grain.