Complete the notes. Write NO MORE THAN TWO WORDS for each answer.

The role of sleep in humans and animals

Importance of sleep in animals

• Compared to those without food, animals without sleep are more likely to suffer from [1].

• Sleep is necessary for all animals, whether they are reptiles, [2] or fish.

Differences in animals’ sleep and reasons for their ways of resting

♦ Dolphins
• swim to the surface when sleeping, because they need to [3].

♦ Birds
• are constantly [4] in the presence of numerous predators.

♦ Horses
• do most of their sleeping standing up.

• do occasionally take short naps lying down. Lying in one position for a long time could well injure a horse, because their [5] are delicate.

Potential problems encountering

• Animals can also have [6], the same as humans.

Importance of sleep in humans

• It helps us to organise our [7] of the day.

• It plays a key role in [8].

e.g.

• Because of the similar sleeping pattern to that in humans, [9] are studied in order to increase our knowledge of human physiology.

• Scientists choose to study the [10] of the fruit fly in order to know the function of the human gene and understand developmental processes in humans.