Ans. Plants produced by vegetative propagation take less time to grow and bear flowers and fruits earlier than those produced from seeds. The new plants are exact copies of the parent plant, as they are produced from a single parent.

 

Ans. A pollen grain on the stigma grows in a tiny tube, all the way down the style to the ovary. This pollen tube carries a male gamate to meet a female gamate in an ovule.

 

Ans. Flowers are so colourful and fragrant to attract insects which help in the process of pollination.

 

 

Ans. (a) vegetative propagation; (b) unisexual flowers; (c) pollination; (d) fertilisation; (e)wind insects, water.

 

Ans. The various methods of asexual reproduction are:

(i) Vegetative propagation, for example stem cutting of rose or Champa.

(ii) Budding, for example reproduction in yeast by budding.

(iii) Fragmentation, for example Fragmentation in spirogyra. 

(iv) Spore formation, for example reproduction in fern.

 

Ans. In this type of reproduction male gamete (sperm) combines with the female gamete(ovum) in animals to form zygote.

 

Ans. Sexual Reproduction

(i) It occurs both in lower and the higher organisms but mostly in higher plants and animals.

(ii) In it, there is fusion of two (male and female) gametes and for this the sex is required. 

(iii) The new individual formed is identical to the parent.

Asexual Reproduction

(i) Usually occurs in lower organisms. 

(ii) Only one parent is sufficient in a sexual reproduction.

(iii) The new individual formed is similar but not identical to the parents.

 

Ans.         

Fig. Reproductive parts of a flower.

 

Ans. The transfer of pollen from the another to the stigma of a flower is called pollination. If the pollen lands on the stigma of the same flower, it is called self- pollination. When the Pollen of a flower lands on the stigma of another flower of the same plant, or that of a different plant of the same kind, it is called cross- pollination.[Fig (a)and (b)].

Fig. Pollination in flowers.

 

 

     Fig. Fertilisation (zygote formation) in flowers.

 

Ans. In nature same kind of plants grow at different places. This happens because seeds are dispersed to different places. Sometimes, after a walk through a forest or a field or a park, we may have found seeds or fruits sticking to our clothes. 

Seeds and fruits of plants are carried away by wind, water and animals. Winged seeds such as those of drumstick and maple [fig. (a) and (b)], light seeds of grasses or hairy seeds of aak (Madar) and hairy fruit of sunflower [Fig. (a),(b)], get blown off with the wind to far away places. Some seeds are dispersed by water. These fruits or seeds usually develope floating ability in the form of spongy or fibrous outer coat as in coconut. Some seeds are dispersed by animals, especially spiny seeds with hooks which get attached to the bodies of animals and are carried to distant places. Examples are: Xanthium (Fig.) and Urena.

Fig. Seeds of

(a) drumstick and 

(b) Maple. 

Fig. (a) The hairy fruit of sunflower and 

        (b) hairy seed of Madar (aak).

some seeds are dispersed when the fruits burst with sudden jerks. The seeds are scattered far from the parent plant. This happens in the case of castor and balsam.

               Fig. Xanthium

 

Ans. (a) (iii); b (v); (c) (ii); (d) (i); (e) (iv).

 

Ans. (a) (iv); (b) (i); (c) (iv); (d) (iii); (e) (ii).