Find out the correct sentence

(i) hybridization means crossing between genetically dissimilar plants

(ii) cross between two varieties is called as inter-specific hybridization

(iii) introducing genes of desired characters into a plant gives genetically modified crop

(iv) cross between plants of two species is called as inter varietal hybridization

Which one is not a source of carbohydrate?

Weeds affect the crop plants by

Which one of the following species of honey bee is an Italian species?

Find out the correct sentence about manure

(i) manure contains large quantities of organic matter and small quantities of nutrients

(ii) it increases the water holding capacity of sandy soil

(iii) it helps in draining out of excess of water from clayey soil.

(iv) its excessive use pollutes environment because it is made of animal excretory waste