CIE iGCSE Co-Ordinated Science B13.3 Homeostasis Exam Style Questions Paper 3
Question
(a) Fig. 7.1 shows a cross‐section through human skin.
(i) Table 7.1 shows some information about two of the parts labelled in Fig. 7.1.
Complete Table 7.1.
(ii) A human has a fat layer in the skin of 3cm.
A whale has a fat layer in the skin of 50cm.
Explain why whales are better adapted to a cold environment.
………………………………………………………………………………………………………………………….
………………………………………………………………………………………………………………………….
………………………………………………………………………………………………………………………….
………………………………………………………………………………………………………………………….
(b) Tick (√) two boxes to show the role of the brain in the maintenance of internal body temperature.
(c) State the word that is used to describe the maintenance of a constant internal environment.
……………………………………………………………………………………………………………………………
▶️Answer/Explanation
Ans : 7(a)(i)
7(a)(ii) whales have a thicker fat layer ;
fat provides insulation / ref to insulator etc ;
7(b)
7(c) homeostasis ;
Question (a)
Fig. 4.1 is a diagram of a cross-section through skin tissue.
Identify the parts labelled A, B and C in Fig. 4.1.
A: …………………………………………..
B: …………………………………………..
C: …………………………………………..
▶️Answer/Explanation
Answer:
A: Sweat gland
B: Fat (fatty tissue)
C: (Hair) erector muscle
Explanation: The diagram shows a cross-section of skin tissue. Part A is the sweat gland, which is responsible for producing sweat to help regulate body temperature. Part B is the fat (fatty tissue), which acts as an insulator and energy store. Part C is the hair erector muscle, which contracts to make hair stand up, helping to trap air and provide insulation.
Question (b)
Complete the sentences to describe how the body responds in cold conditions using words from the list.
Each word may be used once, more than once or not at all.
blood energy muscles skin
When the internal body temperature decreases, the brain detects the low temperature of the …………………………………………..
To increase the body temperature ………………………………………….. contract and relax rapidly. This is called shivering.
This increases the rate of respiration which releases ………………………………………….. in the form of heat.
▶️Answer/Explanation
Answer:
When the internal body temperature decreases, the brain detects the low temperature of the blood.
To increase the body temperature muscles contract and relax rapidly. This is called shivering.
This increases the rate of respiration which releases energy in the form of heat.
Explanation: In cold conditions, the body detects a drop in temperature through the blood. To generate heat, muscles contract and relax rapidly, causing shivering. This increases the rate of respiration, releasing energy in the form of heat to maintain body temperature.
Question (c)
The boxes on the left show some sentence beginnings. The boxes on the right show some sentence endings.
Draw one line to link one box on the left to one box on the right to show the correct definition of homeostasis.
▶️Answer/Explanation
Answer:
Homeostasis is the maintenance of internal environment.
Explanation: Homeostasis refers to the maintenance of a stable internal environment within the body, despite changes in external conditions. It involves regulating factors such as temperature, pH, and glucose levels to ensure optimal functioning of the body’s cells and organs.