BIOLOGY [2 Mark Question Answer]

Corolla is the second whorl composed of floral leaves called petals. Petals are usually brightly coloured to attract insects for pollination. Petals also protect the inner whorls. The shape and colour of corolla vary greatly in plants.

The calyx is the outermost whorl of a flower which is composed of sepals. Generally, these sepals are green, leaf-like, and protect the inner whorls of the flower in bud condition. They are also involved in producing food by photosynthesis.

In certain flowers like tomato and brinjal, the calyx remains attached even after the formation of the fruit and does not wither away. Such calyx is called a persistent calyx.

Inflorescence	Flower
It refers to the arrangement of flowers on the floral axis.	Flower is a modified shoot in which internodes are shortened and I eaves are modified into the floral structure.
Inflorescence is of two types - Racemose and cymose.	Flowers are of six types - complete incomplete, bisexual, unisexual, actinomorphic, and zygomorphic.

There are six different types of flowers.
These are: complete, incomplete, bisexual, unisexual, actinomorphic, and zygomorphic.

The flower is the reproductive unit in the angiosperms and is meant for sexual reproduction. Flowers produce seeds from which new plants grow in the future. So the main function of a flower is to perpetuate the species

Perianth - When the calyx and corolla are not distinct in a flower (eg. - lily), the whorl is collectively called perianth.
Function - The members of the perianth, called tepals are usually brightly coloured and bear scent. This attracts insects which aid in pollination. They also protect the flower in bud condition.

Incomplete flower - A flower lacking one whorl out of the four whorls is said to be an incomplete flower.
Function - An incomplete flower contains either male or female reproductive organs.

Placentation - The manner in which the placenta and ovules are arranged inside the ovary wall is known as placentation.
Function - Placentation helps in the best arrangement of ovules within the ovary. Placentation also helps in plant classification.

Gynoecium - It is the innermost whorl of the flower-bearing the female reproductive parts.
Function - The ovary of gynoecium produces ovules which bear the female gamete.

Inflorescence - The arrangement of flowers on the floral axis is called an inflorescence.
Function - Inflorescence facilitates the best arrangement and display of flowers on a branch without any sort of overcrowding. It also facilitates pollination via a prominent visual display and more efficient pollen uptake and deposition.

Ray florets	Disc florets
They are arranged on the rim of the receptacle.	They are grouped in the center.
These florets may be sterile or fertile.	These florets are bisexual.
They are zygomorphic	They are actinomorphic

Racemose inflorescence	Cymose inflorescence
Here oldest flower is at the base while the youngest flower is at the apex.	Here oldest flower is in the centre and youngest flower towards the periphery.
Here the main axis continues to grow.	Here, the main axis terminates in a flower, hence it is limited in growth.

Inflorescence	Flower
It refers to the arrangement of flowers on the floral axis.	Flower is a modified shoot in which internodes are shortened and I eaves are modified into the floral structure.
Inflorescence is of two types - Racemose and cymose.	Flowers are of six types - complete incomplete, bisexual, unisexual, actinomorphic, and zygomorphic.