Write a short note on:
a) Adaptations of desert plants and animals.
b) Adaptations of plants to water scarcity.
c) Behavioural adaptations in animals.
d) Importance of light on plants.
Write a short note on:
a) Adaptations of desert plants and animals.
b) Adaptations of plants to water scarcity.
c) Behavioural adaptations in animals.
d) Importance of light on plants.
(a) Adaptations of desert plants
(i) Thick cuticle on their leaf surface.
(ii) Stomata arranged in deep pits to minimise water loss.
(iii) Stomata remain closed during the daytime.
(iv) Special photosynthetic pathway (CAM).
(v) Leaves reduced to spines to avoid stomatal loss of water (in Opuntia).
(vi) Photosynthesis is taken over by flattened stems.
(b) Adaptations of desert animals
(i) Very little water requirement.
(ii) Are able to use internal metabolism as a source of water.
(iii) Produce concentrated urine and solid faeces.
(iv) Have mechanisms to prevent loss of water in breathing.
(v) Burrowing habit to avoid day heat.
(c) Behavioural adaptations in animals to avoid stressful or harmful conditions are as follows.
(i) Aestivation
(ii) Camouflage
(iii) Hibernation
(iv) Migration
(v) Mimicry.
d) Importance of light on plants.
(i) The length and extent of light determine the growing processes of plants, e.g., seed germination, growing budding, blooming, flowering and the production of seed.
(ii) To grow and develop, plants need sunlight as a source of energy to make their food (photosynthesis). The amount of light and its intensity influences the rate of photosynthesis.
(iii) The time for which light is available (photoperiodism) and its intensity effects, the reproduction in sexually reproducing plants.
(a) Adaptations of desert plants
(i) Thick cuticle on their leaf surface.
(ii) Stomata arranged in deep pits to minimise water loss.
(iii) Stomata remain closed during the daytime.
(iv) Special photosynthetic pathway (CAM).
(v) Leaves reduced to spines to avoid stomatal loss of water (in Opuntia).
(vi) Photosynthesis is taken over by flattened stems.
(b) Adaptations of desert animals
(i) Very little water requirement.
(ii) Are able to use internal metabolism as a source of water.
(iii) Produce concentrated urine and solid faeces.
(iv) Have mechanisms to prevent loss of water in breathing.
(v) Burrowing habit to avoid day heat.
(c) Behavioural adaptations in animals to avoid stressful or harmful conditions are as follows.
(i) Aestivation
(ii) Camouflage
(iii) Hibernation
(iv) Migration
(v) Mimicry.
d) Importance of light on plants.
(i) The length and extent of light determine the growing processes of plants, e.g., seed germination, growing budding, blooming, flowering and the production of seed.
(ii) To grow and develop, plants need sunlight as a source of energy to make their food (photosynthesis). The amount of light and its intensity influences the rate of photosynthesis.
(iii) The time for which light is available (photoperiodism) and its intensity effects, the reproduction in sexually reproducing plants.
