Question

Which of the following statements is/are true for Pinus?
I. Pinus produce one type of spores.
II. The modified leaf, bearing sporangium is known as sporophyll.
III. They have a diplontic life cycle.

• A. I and II
• B. II and III
• C. Only I
• D. I, II, II

Answer 1

The correct option is B II and III

Pinus is a gymnosperm. It is heterosporous as it produces two different spores - microspores and megaspores.

The spores are produced in the sporangium, which is borne on sporophylls. Sporophylls are modified leaf-like structures which are spirally arranged to form a cone or stobili. The male cone or the male strobili has the microsporophylls which bear the microsporangium. Microsporangium produces microspores, which gives rise to pollen grain. The pollen grain contains the male gametophyte. The female cone bears the ovule which is functional megaspore.

In Gymnosperms, the diploid sporophyte is the dominant, independent and photosynthetic phase. The gametophytic phase is represented by the single to few-celled haploid gametophyte. This is described as a diplontic life cycle.