Before starting preparations, the students are advised to get completely familiar with the topics covered in the NCERT solutions. Solved examples for Practicing and perfection are given below.
CBSE NCERT Solutions for Class 7 Science Chapter 12:
Explain what you understand by sexual reproduction.
The mode of reproduction in which two parents are involved for the production of
new generation is known as sexual reproduction. It occurs in higher plants. The male gamete is carried by pollen grains to the stigma of the flowers for fusion. Fusion of male and female gamete forms zygote that is genetically different from the parent plants. The progeny inherit features of both parent plants. In sexual reproduction, the parent plants survive even after reproduction.
Describe the various ways by which seeds are dispersed.
Various ways by which seeds are dispersed are:
(i) Dispersal by wind: Light seeds or hairy seeds and hairy fruit get blown off with the wind to far away places. Examples: Sunflower, maple, drumsticks etc.
(ii) Dispersal by water: Fruits or seeds which develop floating ability in the form of spongy or fibrous outer coat are carried away with to different places. Example: Coconut.
(iii) Dispersal by animals or birds: Spiny seeds with hooks which get attached to the bodies of animals and are carried to distant places. Also, the fruits are eaten up by animals and birds and their seeds get dispersed to faraway places. Examples: Xanthium, Urena, Mango etc.
(iv) Dispersal by bursting: Some seeds are dispersed when the fruits burst with sudden jerks and the seeds are scattered far from the parent plant. Examples: castor and balsam.
(v) Dispersal by human being: Humans also play an important role in seed dispersal
especially during plantation and farming. They also transport fruits which also help in the dispersal of seeds.
Bryophyllum can reproduce by its
Option A : stem
Option B : leaves
Option C : roots
Option D : flower
Correct option: B
Bryophyllum can reproduce by its leaves.