Question

In …… Branches, the leaves are dimorphic.
A.pinus
B.Gnetum
C.Both of the above
D. Cycas

Answer 1

Dimorphic as the name suggests ‘di'- two and 'morphic'- forms, it is referred to when the plant contains two forms of leaves which differ in size and shape. Two different forms are scale leaves and foliage leaves are the 2 modifications of this which can be observed in different plant species.

Complete answer:

Pinus: pinus plants are monecious plants just like gymnosperms; they are considered as Evergreen plants with spiral branches and they have a conical appearance. They are completely covered with bark and the leaves branches are modified into both scale leaves and foliage leaves. Hence Pinus plants have dimorphic leaves.
So, option A is correct.
Gnetum: gnetum is also a gymnosperm plant they are a special type of plants in gymnosperms because they consist of vessels in the stems and most of the characteristics of gnetum resemble Angel sperms and the leaves of gnetum are modified as of pinus they have to desiccate leaves and pinnate leaves with 2 different forms hence gnetum plants have dimorphic leaves
So, option B is correct.
Both of the above are correct both gnetum and pinus branches consists of dimorphic leaves
Option C is the correct answer.
Cycas: it is also a gymnosperm plant with large crows and pinnate leaves and the leaves of these species are edible which mean their leaves are not either foliage or scaly which could make them non-edible
Hence option D is not correct

Hence option C is correct.

Note:
Dimorphic leaves are mostly observed in the evergreen azaleas plants. All the pinus and gnetum plants are well known for the similarity in the dimorphism of the leaves branches.
Dimorphic leaves were first observed and studied by Darwin which he explained the formation and pattern in his one of the very famous books ‘The Origin of Species’.