Question

Animals at the Extremes: In what sense (environmentally) are animals living at the extremes when they live in deserts and polar environments? In the table below, describe these environmental challenges, and name + briefly describe an animal that lives in the environment, including its physiological adaptions and behavioral strategies for extreme survival.

Environment	environmental challenges	physiological adaptions	behavioral strategies
desert
polar

Answer 1

Biome	Environmental challenges	Physiological adaptations	Behavioural strategies
Desert	Low level of rainfall Extremely hot days and cold nights Vegetation does not grow very tall Desert biome can only accommodate small animals, rodents, and reptiles. Extreme scarcity of water Occurrence of Sand storms when the wind picks up sand from the surface.	Most desert animals get their water from the food they eat: succulent plants, seeds, or the blood and body tissues of their prey. Animals have mechanisms to save water Scorpions and wolf spiders have a thick outer covering which reduces moisture loss. The kidneys of desert animals concentrate urine, so that they excrete less water. Many desert animals like camel can store fat in their humps. They depend on this stored fat for energy and moisture for long trips through the desert. They have extremely long large intestine for absorbing water. Camels have long eyelashes and thin slit nostrils that can close to protect them from sand storms. Camels also have long muscular legs for walking and wide padded feet for protection from hot sand. · · Plants like Cactus have many physiological adaptations for conservation of water like thick, waxy skin to reduce loss of water and to reflect heat. · Large, fleshy stems to store water. · Thorns and thin, spiky or glossy leaves to reduce water loss. · Spikes protect cacti from animals wishing to use stored water. · Deep roots to collect groundwater. · Long shallow roots which spread over a wide area.	Most of the desert animals are nocturnal in habit to escape from the extreme temperature during the night time and also prevents the evaporative loss of water. Desert animals like kangaroo rats and lizards, are burrowing in habit, which do not get too hot or too cold and have more humid (damp) air inside. Desert ground squirrels enter a long term aestivation in deep burrows.
Polar	Extreme grisly cold climate Most areas are covered with snow Scarcity of food Darkness in winter Continuous light in summer.	Animals like polar bears have a thick layer of fat under the skin to insulate the body and prevent heat loss. The white fur of polar bears helps them to camouflaged against the white background of snow protecting them from predators and also helps them catch prey. Two thick layers of fur act as an insulator protecting them from the surrounding harsh climate. They have a strong sense of smell that helps them in catching prey. Penguins have webbed feet and they streamline their body while swimming which makes them good swimmers.	Animals living in polar regions include a variety of fishes, reindeers, seals, whales, foxes and birds. Fishes are able to remain underwater for long periods of time and survive the cold weather. Birds migrate to warmer regions till the winter gets over. The polar bear carries out physical activities like swimming in order to keep it warm. To prevent over heating they move only slowly and rest often. They can remain submerged in water closing their nostrils. Some polar animals hibernate during winter. Polar bears do not hibernate But in winter Pregnant polar bear females stay long duration in their dens in winter to give birth to their cubs. Birds like penguins huddle together in groups to keep themselves warm.