Q32.Which of the following statement is true about Gymnosperms?
(A) Albuminous cells in phloem are absent
(B) The embryo that grows after fertilization is exoscopic in nature
(C) Gymnosperms are dioecious in nature
(D) The embryo that grows after fertilization is endoscopic in nature
Gymnosperms feature endoscopic embryo development after fertilization, where the suspensor pushes the embryo deep into the female gametophyte tissue. This contrasts with exoscopic development seen in some other plants. Option (D) is correct.
Option Analysis
-
(A) Albuminous cells in phloem are absent: Incorrect; gymnosperms possess albuminous cells (sieve cell companions), analogous to angiosperm companion cells.
-
(B) The embryo that grows after fertilization is exoscopic in nature: Incorrect; exoscopic means outward embryo growth, typical of pteridophytes, not gymnosperms.
-
(C) Gymnosperms are dioecious in nature: Incorrect; many are monoecious (e.g., Pinus), though some like Cycas are dioecious.
-
(D) The embryo that grows after fertilization is endoscopic in nature: Correct; suspensor embeds embryo into nutritive tissue.
Introduction to Gymnosperm Characteristics
Which of the following statement is true about gymnosperms identifies endoscopic embryo development post-fertilization as accurate. Gymnosperms (naked seeds) evolved vascular adaptations with unique phloem and reproduction.
Endoscopic Embryo Development
In gymnosperms like Pinus, the suspensor orients embryo inward into haploid female gametophyte (endosperm precursor), termed endoscopic. This ensures nutrient access pre-seed dispersal.
Debunking Other Statements
Albuminous cells exist in gymnosperm phloem; dioecy is not universal; exoscopic development belongs to ferns.
