BIOLOGY [1 Mark Question Answer]

When a flower arises in the axil of a leaf-like structure, this structure is known as a bract. Because bracts are large and brightly coloured structures, they are often mistaken for petals. This helps to attract insects for pollination.

The contents of the pollen sacs would come out through agents like air, wind, insects leading to pollination in flowers.

Contents of the pollen sacs in B are male gametes.

In the above figure A represents stamen. Stamens collectively form Androecium.

Salvia sepals are petaloid because the three sepals are united and are red in color like petals. Hence, they are undifferentiated from the petals.

Ray florets of sunflowers are neuters because both male and female reproductive organs are lacking or absent.

The androecium of pea flower is diadelphous because the filaments of the anther are united in two bundles. In the case of pea, out of ten, nine stamens form a staminal tube while one is free.

Stigma:
Location: Terminal knob-like part
Function: Serves as the landing place for pollen grains during pollination

Anther:
Location: Part of the stamen
Function: Produces male gametes or pollen grains

Thalamus:
Location: Tip of the flower stalk
Function: Bears all the parts of the flower

Placenta:
Location: Cushion or swollen region in the ovary
Function: Gives origin to ovules

A flower that contains both stamens and carpels is called bisexual or hermaphrodite flower. E.g. Hibiscus.

A flower that contains only the carpels, i.e., female parts of a flower is called female or pistillate flower. E.g. Date palm.

A unisexual flower which contains only the stamens, i.e., male parts of a flower is called male or staminate flower. E.g. Eastern cottonwood.

If one or more sets of floral structures are missing, the flower is called incomplete flower. E.g. American elm.

Diadelphous

Polyadelphous

Monadelphous