Advertisements
Advertisements
प्रश्न
What is puberty?
Advertisements
उत्तर
The rate of general body growth begins to slow down, reproductive tissues begin to mature. This period during adolescence is called puberty.
संबंधित प्रश्न
How does the process of fertilisation take place in flowers?
What is the function of a flower?
When an insect sits on the flower of a plant then some particles A present in the top of little stalks in the flower attach to its body hair. When this insect now sits on the flower of another similar plant, then particles A attached to the hair of insect are put on the top of a flask-shaped organ at the centre of flower. The particle A grows a long tube b from the top of flask-shaped organ through which C moves down and reaches the bottom part of flask-shaped organ. Here C fuses with the nucleus of d contained in structure E. the fusion of C and D forms a new cell f which grows and develops into a seed of the plant.
(a) What are particles A? What is the process of transferring A from one flower to another flower of similar plant by the insect known as?
(b) What is the name of tube B?
(c) What is C which moves down through the tube B?
(d) Name D and E.
(e) What is F?
State whether the following statement is true (T) or false (F):
Stamens make egg cells.
Draw a diagram of the longitudinal section of a flower exhibiting germination of pollen on stigma and label (i) ovary, (ii) male germ-cell, (iii) female germ-cell and (iv) ovule on it.
Draw a diagram of a pistil showing pollen tube growth into the ovule and label the following:
Pollen grain, male gamete, female gamete, ovary.
Distinguish between unisexual and bisexual flowers giving one example of each. Draw a diagram showing process of germination of pollen grains on stigma and label the following parts:
(a) Female germ cell
(b) Male germ cell
(c) Ovary
What is meant by pollination?
Find the odd one out:
Identify the parts A, B, C, and D?
