Pre AP Biology -GEN 4.2 Sexual Reproduction (Meiosis)- MCQ Exam Style Questions -New Syllabus
Pre AP Biology -GEN 4.2 Sexual Reproduction (Meiosis)- MCQ Exam Style Questions – New Syllabus 2025-2026
Pre AP Biology -GEN 4.2 Sexual Reproduction (Meiosis)- MCQ Exam Style Questions – Pre AP Biology – per latest Pre AP Biology Syllabus.
▶️ Answer/Explanation
The correct option is a.
Angiosperms are the only group of plants that produce true flowers as reproductive structures.
They undergo double fertilization, where one sperm fuses with the egg and another with the polar nuclei.
Germination is not unique to angiosperms, as gymnosperms and ferns also germinate from seeds or spores.
Coevolution occurs across many kingdoms, such as between predators and prey or hosts and parasites.
Therefore, the combination of flowers and double fertilization defines the uniqueness of angiosperms.
This process ensures the formation of both a diploid zygote ($2n$) and a triploid endosperm ($3n$).
▶️ Answer/Explanation
The correct option is b.
Double fertilization is a unique process in angiosperms involving two sperm cells.
The first $1$st sperm fuses with the egg cell to form a diploid ($2n$) zygote.
The $2$nd sperm fuses with the central cell (containing two polar nuclei).
This second fusion creates a triploid ($3n$) primary endosperm nucleus.
The zygote develops into the embryo, while the endosperm provides nutrition.
Options a, c, and d are incorrect as they misidentify the target cells or outcomes.
▶️ Answer/Explanation
The correct option is d.
The microspore is the first cell of the male gametophyte generation.
It undergoes an asymmetrical mitotic division ($1$ mitosis).
This division results in a large tube cell (vegetative cell) and a smaller generative cell.
The tube cell is responsible for pollen tube growth.
The generative cell later divides to form two male gametes (sperm cells).
At the initial stage of microspore division, only two cells are formed.