11
Nitrogen fixation is shown by prokaryotes and not eukaryotes. Comment.
Explanation
Few prokaryotes like Rhizobium, Anabaena and Nostoc contains the enzyme nitrogenase, needed for the biological nitrogen-fixation. Eukaryotes do not possess this enzyme, therefore are unable to fix nitrogen.
12
Carnivorous plants like Nepenthes and venus fly trap have nutritional adaptations. Which nutrient do they especially obtain and from where?
Explanation
Nepenthes and venus fly trap grow in nitrogen deficient soil. So, they make up their nitrogen deficiency by trapping insects for which they have developed special adaptations.
13
Think of a plant which lacks chlorophyll. From where will it obtain nutrition? Give an example of such a type of plant.
Explanation
An angiospermic plant called Monotrapa do not contain chlorophyll. It grows on some other plant as a parasite and derive nutrition from the host plant. This plant is commonly known as ghost plant.
14
Name an insectivorous angiosperm.
Explanation
(i) Dischidia
(ii) Utricularia
15
A farmer adds Azotobacter culture to soil before sowing maize. Which mineral element is being replenished?
Explanation
Azotobacter is a free living bacteria in the soil. It helps some cereal crops like maize (Zea mays) in nitrogen fixation. The farmer adds Azotobacter culture to the maize field for enhancing the nitrogen element in the soil by the process of biological nitrogen-fixation.