Question

In Pinus, male cone bears a large number of
(a)Ligules
(b)Anthers
(c)Micro-sporophylls
(d)Mega-sporophylls

Answer 1

Hint: Gymnosperms are heterosporous and produce smaller microspore and larger megaspore. The two varieties of spores are developed inside sporangia that are borne on sporophylls which are organized spirally along an axis to create lax or compact strobili or cones.

Complete answer:
In Pinus, the male cone bears a large number of ‘Micro-sporophylls’.
Sporophylls are of two types:
-Microsporophylls
-Megasporophylls
Microsporophylls are compactly arranged on a central axis to form male strobili or microsporangiate/ pollen cones. They bear microsporangia where microspore mother cells undergo meiosis to form microspores. The microspores mature into a male gametophytic generation which is distinctly reduced or haploid and is restricted to only a finite number of cells. This reduced gametophyte is known as pollen grain. The maturation of pollen grains happens inside the microsporangia.

Additional Information:
Megasporophylls are compactly arranged to form female strobili or microsporangiate/seed cones. They bear the integument megasporangia (ovules). The ovule or the integument megasporangium mainly consists of a body called nucellus protected by an envelope or integument.
General characteristics of Gymnosperms:
-They involve from medium-sized trees to shrubs.
-The male and female gametophytes do not possess a free-living existence.
-The plants represent the diploid sporophytic phase in the life cycle.
-Their plant body is modified into root, stem, and leaves.
-The roots are mainly tapping roots. The direct extension of the radicle heads to the development of the primary root which grows within the soil. The primary roots along with its branches make up the taproot system.
-Roots in Pinus have a fungal association in the form of mycorrhiza. Mycorrhiza is a symbiotic association of a fungus and the root of a higher plant.
So, the correct answer is ‘Microsporophylls’.

Note: -Seeds of Pinus gerardiana known as chilgoza are edible. They are eaten after roasting.
-The needle of Pinus is used in making fiberboards that are used in making packing cases.
-Sulfur shower: It is a process in relation to pollination occurring in pine trees. Since Pinus bears cones, they are often termed as conifers. They possess cones and when pollen cones mature, they release enormous quantities of pollen grains in the air and it looks like a yellow cloud full of yellow-colored pollen. Hence, it is called a sulfur shower.