The Arctic muskox (Ovibos moschatus) is adapted to survive the extreme cold of the northern tundra, where winter temperatures can drop below −50∘C-50^\circ\text{C}−50∘C.
Muskoxen are massive animals, with adults weighing up to 400 kg400\text{ kg}400 kg, compared to smaller ruminants in warmer climates. Explain how having a large body size helps the muskox to survive in freezing Arctic temperatures.
Muskoxen possess an inner layer of extremely dense, fine wool called qiviut, beneath a thick outer coat of guard hairs, as well as a subcutaneous fat layer. Suggest how these features help them survive.
In many Arctic mammals, the powerful muscles that operate the lower limbs (such as the hooves) are located deep within the warm body core (shoulders and hips) rather than in the extremities, connected by long tendons running down the leg.
Suggest how this anatomical arrangement benefits the animal in cold environments.
Suggest one mechanical property that these long tendons must possess.
During severe winter blizzards, muskoxen frequently form tight, packed circles or huddle closely together. Explain how this behavioral adaptation is an advantage.
31 exam-style questions on Edexcel IGCSE Biology The organism in the environment. Each one has a worked solution and a mark scheme showing where the marks go.