Terrestrial adaptation - class-VI

Co evolution is caused by the selection pressure that each of the two species exerts on the other since there has been no co-evolved herbivore with prickly cactus, it became abundant in Australia.

Stems are covered by waxy coating in order to prevent the loss of water and helps in maintaining the water level in the plant under dry conditions.

The process of change by which an organism or species becomes better suited to its environment is known as adaptation.

The trees in mountain habitats usually have cone shape having sloping branches. This shape makes the rainwater and snow to slide off easily.

Stems are modified in cactus in order to perform Photosynthesis. Stems are flattened and green having thick waxy coating over them and helps in performing photosynthesis as leaves are converted into spines.

Pine tree is found in the mountains.

Fir trees are found in mountains.

Plants is the biotic component.

Cactus are found in deserts as they are adapted to live in dry conditions.

Small changes that take place in the body of a single organism over short periods, to overcome small problems due to changes in the surroundings, are called Acclimatisation.

The broad-leaved trees found on mountains shed their leaves before the onset of winter. This prevents such trees from losing water from their leaves.

In the Northern Hemisphere, north-facing slopes receive less direct sunlight, are cooler, often support different vegetation (higher elevation types), and are better for retaining snow for skiing compared to south-facing slopes.

Redwood trees (Sequoia sempervirens) are native to the coastal regions of Northern California and a small part of Oregon. They are famous for being the tallest trees on Earth.

Temperature affects the the absolute size of an animal and the relative
proportions of various body parts, Birds and mammals attain grater body
size in cold regions than in warm areas. But poikilotherms are smaller
in cold region. This is Bargeman's rue. This is true because small
animals have larger surface area relative to their volume, so if they
are in cold, they lose their body heat very fast. In cold climate,
reduced surface area to volume ratio is ideal. So, the correct answer is 'Reduced surface area to volume ratio'.

The animals living in cold climate have various physiological adaptations like:

1) A thick layer of body fat called as Blubber to avoid loss of heat from body tissue.

2) Hibernation is a property of suspended metabolism in these organisms to surpass cold conditions.similar mechanism called aestivation exists in desert animals to survive in arid and hot conditions.

3) Increased tendency to shiver causes an increase in body temperature because of exercise thus help to withstand low temperatures.

4) The reduced surface area to volume ratio to prevent heat loss from the body surface. So, the correct answer is 'Aestivation'.

Animals that live in colder areas have to protect their bodies against extremely cold environmental conditions. Their bodies cannot withstand such cold climates. So, they have a thick white fur over their bodies. This provides an additional layer over their skin. As a result, the air gets trapped in this layer and it cannot pass through it, keeping their bodies insulated against the excessive cold.