Question

Assertion
The female cone of cycas is not a true cone.
Reason
It’s formation checks the growth of the stem.
A. If both Assertion and reason are true and Reason is the correct explanation of Assertion.
B. If both Assertion and reason are true, but the Reason is not the correct explanation of Assertion.
C. If the Assertion is true but Reason is false.
D. If both Assertion and reason are false.

Answer 1

Hint: Cycas are amazing dioecious plants, but male and female plants do not differ in their vegetative stage. Compact male cones develop at the ends of the stems of male plants. However, Cycas differs from the other members of the genus Cycadaceae in terms of the female cone.

Complete answer:
Let’s first study cycas male and female cones.
Male cone-The male cone or the male strobilus is a large, cone, or egg-shaped, compact, solitary, short-stemmed structure that usually has a terminal position. Sometimes it reaches 1.5 meters in length. The axis of the cone is in the center of the cone. Several vertically mounted microsporophylls are arranged in tightly spaced spirals around the axis of the cone. There are many young leaves at the base of the male cones. All microsporophylls in the male cone are fertile, except for a few in the basal and apical parts.
Female cone-The female reproductive organs are megasporophyll. Each female plant produces several megasporophylls annually in acropetal sequences above each leaf canopy and leaf scaly. No female cones are formed. The number of megasporophylls is much greater than the number of leaves on the leaf stalks. During megasporophyll formation, the apical meristem is not consumed like male cones, and therefore stem growth continues and therefore monopodial growth of female plants.
The female reproductive organs are megasporophyll. Above each leaf crown and scaly leaf are numerous megasporophylls around the monopodial tips of the female plant.
So from the above points, it’s clear that in cycas male cone is present and the female cone is present and when the female cone is absent then the formation of cone doesn’t occur so the reason stated is incorrect.
So, the correct answer is “Option C”.

Note:
Megasporophyll appears spirally in acropetal sequences around the stem tips of the female plant. Cycas megasporophylls are considered to be modified leaf blades. Megasporophylls are produced as fronds every year. It has a proximal stalk, middle ovipositor, and upper pinnate sterile area. The fertile center produces 2-12 round sessile ovules in two rows. Cycas ovules are the largest in the plant kingdom with a diameter of 6-7 cm. At a young age, the ovules are green and covered with brown hair. However, after conception, the hair will disappear and look orange to red. The body of the ovules is called a nucellus (megasporangium), which is lined with a solid shell on all sides, except for holes called micro piles. The tip of the nucellus has a pollen chamber and a core beak. The cover consists of three distinct layers: the outer and inner fleshy layer and the middle stone layer.