BMAT 2017 Section 2 Question 25

The picture shows a Siamese cat. This type of cat has a gene which is sensitive to temperature. When this gene is inactive in the cells, the coat colour is pale. When the gene is active, it produces an enzyme which causes the coat colour to be darker. If this cat had grown up in a warmer environment its ears, front of face, paws and tail would be paler than those shown in the picture below.
A student wrote the following statements using this information.
1 The enzyme is denatured at the internal body temperature of the cat so the coat colour is pale.
2 The temperature of the ears, front of face, paws and tail was cooler than the body temperature so they are darker.
3 The coat colour in Siamese cats depends on both genes and the environment.
Which of these statements is/are correct?

Answer:

1 – Wrong
The enzyme is produced by the activation of the gene and not the internal temperature.

2 – Correct
The last line of the paragraph says that IF the cat had grown in a warmer temperature, the ears, front of the face, paws and tail would have been paler. 2 suggests that the temperature of those parts of the body were cooler than the rest of the body and hence, they are darker. So 2 is correct.


3 – Correct
Activation of the gene produces the enzyme which makes the coat colour pale. The environment causes the colour change in the ears, front of the face, paws and the tail.

Sami Qamar

I’m Sami Qamar. I’m a YouTuber, Blogger, and first year med student.

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