Question

________ and _______ are the essential whorl
A.Calyx
B.Corolla
C.Androecium and gynoecium
D.Gynoecium

Answer 1

Hint: Flowers contain the plant's reproductive structures. It has four main parts/whorls which are calyx, corolla, androecium, and gynoecium.

Complete answer:
1.Calyx: It is the outermost accessory set of floral leaves, consisting of sepals. Sepals are green inconspicuous bodies protecting essential whorls against mechanical injuries and desiccation during the bud stage. Sepals of some plants become coloured just like the petals and are called petaloids. If the sepals are free the calyx is named polysepalous, and that they are united the calyx is gamosepalous.

2.Corolla: It is the second accessory whorl of flower, the individual parts of which are known as petals. They create the flowers showy and attractive, because the petals are brightly coloured and infrequently sweetly scented. The function of corolla is protection of essential whorls within the bud stage; and the attraction of insects for pollination. If the petals are free, the corolla is termed polypetalous and if they're united, it's gamopetalous.

3.Androecium: It is the first essential whorl and composed of stamens or microsporophyll which are male organs. A stamen usually has two parts, a slender stalk called filament and a swollen body at the tip of the filament referred to as anther. The anther has usually two lobes on the 2 sides; each lobe, in its turn, has two bag-like bodies, called pollen-sacs or microsporangia, which contain innumerable small unicellular pollen grains or microspores. All stamens don't always bear fertile anthers.

4.Gynoecium: It is also known as pistil. It is the innermost set of floral leaves which occupies a central position on thalamus. It's composed of carpels or megasporophylls which are the feminine organs of the flowers. The ovary contains one or more egg-shaped bodies referred to as ovules, which are nothing but immature seeds. Pistil is also fabricated from one, two, three or many carpels. Accordingly they're monocarpellary, bicarpellary, tricarpellary or polycarpellary. The monocarpellary pistil is termed simple, while others are termed as compound.

Foliar nature of a carpel is clear during a pistil which can be compared to a straightforward leaf. If the leaf is folded along the mid-rib, the two margins meet forming a hollow cavity, which resembles a straightforward pistil. The line where the two margins meet is thought as ventral suture which corresponds to the mid-rib is that the dorsal suture. Along ventral suture soft ridges called placentae, are formed on which ovules are attached. The pistil is named apocarpous, when the carpels are free. If carpels remain inserted on thalamus, each having its own ovary, style and stigma, but if the carpels are united, the pistil is understood as syncarpous where the common ovary and elegance are usually formed, carpels usually remaining free only within the region of stigmas, e.g. China-rose, cotton.

Hence, the correct answer is option (C)

Note: If any of the four parts is missing, the flower is known as incomplete. Flowers that contain both an androecium and a gynoecium are called perfect, androgynous or hermaphrodites. There are two types of incomplete flowers: staminate flowers contain only an androecium, and carpellate flowers have only a gynoecium.