Question

The condition of fusion of anthers to form a tube with filaments living free is
a. Gynandrous
b. Monadelphous
c. Syngenesious
d. Syncarpous

Answer 1

A flower is defined as the reproductive structure found in flowering plants. The anther is the part of the stamen, is a pollen-producing part of a flower. It has a slender filament supporting the anther. Anthers are two-lobed structures. Two anther lobes contain four elongated cavities or pollen sacs which are called microsporangia.

Complete answer:
Syngenesious or synantherous is the condition of the stamens in which the anthers are fused to form a tubular bundle while their filaments are free. The anthers shed their pollen inward and the style pushes them through the anthers like a piston and shoves them up to present it on top of anthers.

In gynandrous condition, the stamens are fused with the pistil, i.e., in a column. E.g. - orchids.

In monadelphous conditions, Filaments of all stamens are united forming a single bundle but the anthers are free, e.g. cotton, lady’s finger.

In syngenesious condition, the anthers are united to form a tube while filaments are free, e.g., sunflower, marigold.

In syncarpous conditions, two or more carpels are fused together (connate). In other words, carpels are united in a compound ovary. E.g. - Hibiscus, papaver.

Hence, the correct answer is option (C).

Note: In syngenesious plants, the anthers of the filaments are fused to form the tubular mass or group and their filaments remain free.
In the family Asteraceae, such as sunflower, the presence of syngenesious or synantherous condition of androecium is a feature. Sunflower is the most common example.
Unlike, as in the case of syndranous stamen these are not united by both anthers and filaments.