In gymnosperms, the nutritive tissue that nourishes the embryo develops from the female ga… — JAMB UTME

In gymnosperms, the nutritive tissue that nourishes the embryo develops from the female gametophyte before fertilization and is haploid ( $n$ ), whereas in angiosperms, the nutritive endosperm develops after double fertilization and is typically triploid ( $3n$ ).

Answer: Answer

Answer

The statement is True. Gymnosperm nutritive seed tissue is haploid (

n

) and formed prior to fertilization, whereas angiosperm endosperm is triploid (

3n

) and formed after double fertilization.

The statement accurately describes the reproductive biology of spermatophytes. Gymnosperm nutritive tissue is haploid (

n

) female gametophyte tissue established before fertilization. Angiosperm nutritive tissue (endosperm) is formed only after double fertilization and possesses a triploid (

3n

) chromosome count.

Step-by-Step Solution

Analyze gymnosperm seed development and nutritive tissue origin.

In gymnosperms, the female gametophyte tissue matures before fertilization, supplying nutrients to the embryo as a haploid (

n

) tissue.

Double fertilization does not occur in gymnosperms, so no triploid tissue is formed.

Analyze angiosperm seed development and double fertilization.

In angiosperms, double fertilization produces a diploid (

2n

) zygote and a triploid (

3n

) primary endosperm nucleus.

The second sperm cell (

n

) fuses with the central cell containing two polar nuclei (

n + n

Evaluate the comparative accuracy of the stem statement.

The statement correctly contrasts the timing of development and ploidy levels between the two spermatophyte groups.

Both ploidy designations (

n

3n

) and temporal distinctions (before vs after fertilization) in the stem are scientifically accurate.

Key Concept

Nutritive tissue origin, timing, and ploidy differences between Gymnosperms and Angiosperms

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