Question

Mammals like caribou that live in the arctic often use different lipid types in their legs. Legs are more susceptible to heat loss than internal organs, which are closer to the body core and stay warmer. Which adaptations would you expect for lipids in caribou legs?
1. The lipids would be more saturated. True / False
2. The lipids on the fatty acid tails would be shorter. True / False
3. The membranes would contain more cholesterol. True / False

Answer 1

1. The lipid would be more saturated. FALSE

2. The lipids on the fatty acid tails would be much shorter. TRUE

3. The membranes would contain more cholesterol. TRUE

Explanation:

The mammal caribou lives I the extremely cold environment of the Arctic and thus has several physiological adaptations to survive the cold. They have short ears to reduce heat loss and have two layers of fur. The lipids in caribou legs have several adaptations

When compared with saturated fatty acids unsaturated fatty acids are more fluid at low temperatures. Thus the lipids in the legs of caribou are unsaturated to maintain fluid nature at low temperatures of the Arctic. Shorter lipids on fatty acid tails remain more fluid at low temperatures when compared with the longer ones.  

Thus the lipid in the fatty acid tails will be shorter. Similarly the presence of more cholesterol in the membranes would make it more fluid in the cold conditions of the external environment. Thus the membranes would have more cholesterol.