Biology Today - February 2018

Analysis of various PMTs from 2013-

2013

2014

2015

2016

2017

AIPMT/NEET

35593

AIIMS

11131

AMU

754––

Kerala

–564–

K-CET

323––

J & K

–32––

MORPHOLOGY OF FLOWERING

PLANTS - II

FLOWER

• Flower is a specialised condensed shoot meant for carrying out the sexual reproduction
  in plants. It bears floral leaves and gives rise to seeds and fruits. The study of flowers is called
  anthology.
  Carpel or female reproductive part forms the innermost whorl of a flower. The free occurring unit of gynoecium
  is called pistil, which consists of basal swollen ovary, a stalk like style and a terminal receptive part called
  stigma. Inside the ovary ovules are present.

Sepals constitute the lower accessory whorl

called of mostly green, flattened or foliaceous

floral organs. It is mainly meant for protecting

other floral parts in the bud condition.

Stamen is the male reproductive part of a flower.

It is made up of two parts, a stalk like filament

and a knob like terminal anther. Each anther

has two lobes which are attached at the back

by a sterile band called connective.

Thalamus is a modified branch, that represents the

axis of the floral whorls with undeveloped or suppressed

internodes between them.

Petals constitute the upper accessory whorl of

floral organs called corolla which is brightly

coloured to attract insects for pollination. In a

petal, the lower part is usually narrow and is

termed as claw whereas the expanded portion

of the petal is called limb.

Ovary

Stigma

Ovule

Anther Style

Filament

Stamen Carpel

Sepal

Thalamus

Petal

A flower can be

• Bisexual : Both the essential organs are present.


• Neuter : Both the essential organs are absent.


• Unisexual : Only one of the two essential organs is present.


• Unisexual flower would be pistillate (only female parts are present) or staminate
  (only male parts are present).

Class XI