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Multiple Choice
A spore stalk grows from the gametophyte of a moss. What is the next step in its life cycle?
A
The sporophyte produces diploid gametes through mitosis.
B
The spores germinate directly into new sporophytes.
C
The gametophyte undergoes fertilization to form a zygote.
D
The sporophyte produces haploid spores through meiosis.
Verified step by step guidance
1
Understand the moss life cycle: Mosses exhibit an alternation of generations, which includes a gametophyte (haploid) stage and a sporophyte (diploid) stage. The gametophyte is the dominant stage in mosses, while the sporophyte is dependent on the gametophyte for nutrients.
Identify the role of the sporophyte: The sporophyte grows from the gametophyte after fertilization. It is diploid (2n) and its primary function is to produce spores.
Recall the process of spore production: The sporophyte produces haploid (n) spores through the process of meiosis. Meiosis reduces the chromosome number by half, ensuring that the spores are haploid.
Understand the fate of the spores: The haploid spores are released into the environment, where they can germinate and grow into new gametophytes, continuing the life cycle.
Eliminate incorrect options: The sporophyte does not produce diploid gametes (gametes are haploid and produced by the gametophyte), spores do not germinate directly into sporophytes (they germinate into gametophytes), and fertilization occurs before the sporophyte forms, not after. The correct step is that the sporophyte produces haploid spores through meiosis.