Botany and Plant Science

Reserpine is an alkaloid obtained from roots of Rauwolfia serpentina, (sarpgandha) family Apocynaceae. Rauwolfia serpentina contains a number of bioactive chemicals, including reserpine, ajmaline, deserpidine, rescinnamine, serpentinine. It was used for millennia to treat insect stings and the bites of venomous reptiles. Reserpine was used as an attempt to treat high blood pressure and mental disorders, including schizophrenia.

Thus, the correct answer is option A.

Arbor vitae is known as tree of life. Arbor vitae is a branching tree like arrangement of grey and white matter visible in the cross sectional area of cerebellar hemispheres.

Dicotyledonous plants characterized by their butterfly-shaped flowers, composed of a top petal, the standard, followed by two opposing petals on the sides, the wings, followed by a bottom petal, the keel, in which the reproductive organs are situated is known as papilionaceae family. This family is also called as legumes.

Diclinous flowers are flowers which have stamens and pistils on separate flowers, it could be on the same plant or different. The plant could be monoecious or dioecious but the male and female reproductive parts are not present on the same flower. Carica, Morus, and Trichosanthes, all are diclinous. So, the correct answer is option D.

When both sexes are absent from a flower or are non-functional , the flower is said to be  neuter. Neuter flowers have undeveloped or nonfunctional sexual organs. They have pistils and stamens that are nonfunctional or absent. The flowers are androgynous and the plants reproduce  asexually. Ray florets of sunflower are neuter flowers, disc florets are bisexual, also in some more Asteraceae, e.g. Centaurea.

Centripetally arranged sessile flowers on a flattened convex axis are found in Helianthus. The genus is one of many in the Asteraceae that are known as sunflowers. It is distinguished technically by the fact that the ray  flowers, when present, are sterile, and by the presence on the disk flowers of a pappus that is of two awn-like scales that are cauducous. They bear one or several to many wide, terminal capitula (flower heads), with bright yellow ray florets at the outside and yellow or maroon disc florets inside. Several ornamental cultivars have red-colored ray florets. 

A cyclic flower which can be divided into two equal vertical halves by any vertical plane is said to be actinomorphic. Here, petals are in radial symmetry i.e. all the petals are identical in size and shape. The bilaterally symmetrical flowers which are symmetrical in only one plane and can be cut into two equal halves through single vertical pane only are said to be irregular or zygomorphic. Zygomorphic flowers have bilateral symmetry. A flower that can be cut into two equal halves by at least one plane is symmetric flower; it may be bilaterally or radially symmetrical.
Therefore, the correct answer is option B.

A dioecious or unisexual flower bears either male or female sex organs. The plant could be either male or female. When only stamens are present, it is called as staminate flower. When only carpels are present, it is called as pistillate flower. e.g., Papaya and Mulberry.
So, the correct answer is 'Both (C) and (E)

In unisexual flower, androecium (staminate flower) or gynoecium (pistillate flower) any one of them are present in the flower. Cocus nucifera (coconut) flower has either stamens or pistils. 

 Zea mays has diclinous flowers on the same plant. Diclinous flowers are flowers which have stamens and pistils on seperate flowers, it could be on the same plant or different. The plant could be monoecious or dioecious but the male and female reproductive parts are not present on the same flower. Female inflorescences in Zea mays, are tightly enveloped by several layers of ear leaves commonly called husks. Certain varieties of maize have been bred to produce many additional developed ears. The apex of the stem ends in the tassel, an inflorescence of male flowers. When the tassel is mature and conditions are suitably warm and dry, anthers on the tassel dehisce and release pollen. Maize pollen is anemophilous (dispersed by wind) and because of its large settling velocity, most pollen falls within a few meters of the tassel.

Commelina benghalensis, commonly known as the Benghal dayfloweris a perennial herb native to tropical Asia and Africa. These show cleistogamy. Cleistogamy or automatic self-pollination describes the trait of certain plants to propagate by using non-opening, self-pollinating flowers. Virtually all plants that produce cleistogamous flowers also produce hasmogamous ones. The principal advantage of cleistogamy is that it requires less plant resources to produce seeds because development of petals, nectar and large amounts of pollen are not required. This efficiency makes cleistogamy particularly useful for seed production on unfavorable sites or adverse conditions. The obvious disadvantage of cleistogamy is that self-fertilization occurs, which may suppress the creation of genetically superior plants.Therefore, the correct answer is option A.

In Tagetes the flowers are centripetally arranged. Tagetes species vary in size. Most species have pinnate  green leaves. Blooms naturally occur in
golden, orange, yellow, and white colors, often with maroon highlights. Floral heads are typically with both ray florets and disc florets.

A bisexual flower is a flower that contains all the four whorls such as petals, sepals, the male reproductive structure (stamen) and female reproductive structure (pistil). Hence it is also called as a complete or perfect flower.