In the plant life cycle with alternation of generations, what does the diploid sporophyte generation always do?

Introduction / Context:
Many plants, including ferns, mosses, and seed plants, show alternation of generations, where a haploid gametophyte and a diploid sporophyte alternate in the life cycle. Understanding what each generation produces is an important part of basic botany and is frequently tested in general science and biology exams.

Given Data / Assumptions:

• The question is about the diploid generation of the plant life cycle.
• We assume the standard alternation between sporophyte (2n) and gametophyte (n).
• We need to identify what the diploid generation always does.
• No species specific exceptions are being considered.

Concept / Approach:
In alternation of generations, the diploid generation is called the sporophyte because its main function is to produce spores. These spores are formed by meiosis and are haploid. The spores germinate to form the gametophyte, which produces gametes (eggs and sperm). The fusion of gametes forms a diploid zygote, which develops into the sporophyte again. Therefore, the essential role of the diploid generation is spore production, not direct gamete production.

Step-by-Step Solution:
Step 1: Recall that the diploid sporophyte has chromosome number 2n and forms spores.Step 2: Remember that spores are produced by meiosis and are haploid.Step 3: Analyse option B, which states that the diploid generation produces spores, matching this role.Step 4: Recognise that options A and C describe functions or names of the gametophyte, not the sporophyte.Step 5: Option D incorrectly says the diploid generation develops from a spore, but in fact the sporophyte develops from a diploid zygote. Therefore, option B is the only correct statement.

Verification / Alternative check:
Standard plant life cycle diagrams show a circular pattern where a sporophyte produces spores, which become gametophytes, which then produce gametes. The key labels are "sporophyte 2n produces spores by meiosis" and "gametophyte n produces gametes by mitosis". This is repeated for mosses, ferns, and seed plants, confirming that spore production is the defining function of the diploid generation.

Why Other Options Are Wrong:
Option A is wrong because eggs and sperm are produced by the gametophyte, not the sporophyte. Option C calls the diploid generation the gametophyte, which reverses the names and is incorrect. Option D misstates development; the sporophyte comes from a zygote, whereas a gametophyte comes from a spore. Option E claims the diploid generation remains haploid, which is a direct contradiction in terms because diploid means two sets of chromosomes, not one.

Common Pitfalls:
Students often confuse sporophyte and gametophyte because both are multicellular in many plants. Another common error is to think that spores and gametes are the same, but spores germinate into gametophytes, whereas gametes fuse to form zygotes. Remember the word roots: sporo refers to spores, and gameto refers to gametes, which helps keep the roles of each generation clear.

Final Answer:
In alternation of generations, the diploid sporophyte generation always Produces spores by meiosis.