PAU01
Dolphins Turn Diabetes Off and On -- Hope for Humans?
Bottlenose dolphins have what could be called type 2 diabetes, but unlike humans, the animals are
able to turn it off and on—perhaps an evolutionary adaptation to maintain their big brains, new
research suggests. Diabetes may have arisen in Ice Age humans for similar reasons, so the
newfound dolphin on-off switch may be a key to curing type 2 diabetes in people.
Like humans, dolphins have relatively large brains compared to their body sizes—in fact, dolphins
are second only to humans in the ratio between body and brain size.
Scientists know that humans need plenty of a sugar called glucose to keep their brains functioning.
Some researchers think the same might be true for dolphins, since both species send high amounts
of glucose through their bloodstreams.
Dolphins, however, primarily eat fish, which are high in protein and low in sugar. To get enough
glucose from this diet, dolphins have evolved a mostly harmless form of insulin resistance.
Insulin is a hormone that helps the body turn blood sugar into energy. People with type 2 diabetes
either don't make enough insulin or are resistant to its effects. Without insulin to break down
glucose, too much sugar builds up in the blood, leading to complications such as glaucoma, nerve
damage, arterial disease, and kidney failure.
But unlike people, dolphins can activate their diabetes only when the animals need it—and without
the serious side effects. Dolphin diabetes turns on during their short overnight fast and turns off
when they have breakfast in the morning.
Not all experts, however, are convinced that dolphins use blood sugar in the same ways that
humans do. Even though both species are mammals, dolphins and people have very different
metabolisms.
1. Comprehension exercises (2 points)
1.a. According to the text (0.5 points)
a. Without insulin you can suffer from kidney failure.
b. Insulin seldom helps the body change sugar into energy.
c. Dolphins diet is rich enough in glucose.
1.b. According to the text (0.5 points)
a. Dolphins can control their body and brain size ratio.
b. Humans have the largest brains compared to their body sizes.
c. Dolphins are unable to turn type 2 diabetes on and off.
1.c. Although dolphins and humans have different metabolisms they use blood sugar in the
same way as we do.
(Answer ‘True’ or ‘False’ AND write the sentence supporting this idea) (0.5 points)
1.d. Dolphin diabetes switches off during the night and on in the morning.
(Answer ‘True’ or ‘False’ AND write the sentence supporting this idea) (0.5 points)
Pruebas prácticas para preparar la P.A.U. en materia de lengua Inglesa. Logroño, 2010 1
PAU01. Dolphins Turn Diabetes Off and On -- Hope for Humans?
2. Do the following grammar exercises according to the instructions given (2 points)
2.a. Complete the second sentence so that it has a similar meaning to the first one (0.5
points):
- I regret to have missed my train.
- I wish
2.b. Turn the two sentences into a conditional clause (0.5 points)
- We didn’t arrive on time. There was a transport strike
- If there
2.c. Turn the two sentences into a relative clause (0.5 points)
- I have a friend. His name is Paul.
2.d. Write the appropriate verb form of the verb in brackets (0.5 points)
- We needn’t (to have) a passport if we travel around Spain. Your ID is
enough.
3. Identify ONLY FOUR words from their definitions (1 point)
- not able or not likely to cause any hurt or damage.
- started to happen.
- the relationship between two things expressed in numbers to show how much bigger one
is than the other.
- completely certain about something.
- one of the two organs in your body which remove waste from the blood and produce
urine.
- one of the meals of the day.
4. Write a summary of the text of about 30 – 45 words using your own words (2 points)
Pruebas prácticas para preparar la P.A.U. en materia de Lengua Inglesa. Logroño, 2010 2
PAU01. Dolphins Turn Diabetes Off and On -- Hope for Humans?
5. Write a composition of about 100 – 150 words on ONLY ONE of the following topics (3
points)
5.a. Could we learn from animal behaviour?
5.b. Advantages and disadvantages of practicing sports activities.
Pruebas prácticas para preparar la P.A.U. en materia de Lengua Inglesa. Logroño, 2010 3
