Science questions, unit 8
Nama / NameKelas / ClassTarikh / Date
Food preservation technology
39 marks. Use Practice to check each answer as you go, or Exam to answer everything first. Ask a grown-up to help you mark the written answers.
Section A: objective questions
8 marksChoose the best answer for each question.
1
Question 1
What causes food to become spoilt?
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B
Bacteria and fungi decompose food from complex to simpler forms.
2
Question 2
Alia's milk was opened two weeks ago. Which shows that it is spoilt?
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D
Spoilt milk becomes bubbly and lumpy, smells bad and tastes sour.
3
Question 3
What is the purpose of food preservation?
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A
Food is preserved to slow down spoilage by preventing or slowing the growth of microorganisms.
4
Question 4
Food is cooked, sealed in an airtight container and then heated. Which method is this?
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C
In canning the food is cooked, sealed airtight in a can and heated. The lack of air and the high temperature stop microorganisms.
5
Question 5
Which growth factor of microorganisms is removed when fish is dried in the Sun?
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D
Drying removes the water content, so microorganisms cannot survive.
6
Question 6
Which food is preserved by freezing?
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B
Beef, fish and seafood are frozen at 0 °C and below to stop microorganisms from growing.
7
Question 7
Mangoes are soaked in vinegar and sugar. Why do they last longer?
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A
Pickling in vinegar or concentrated sugar or salt makes the acidity unsuitable for microorganisms.
8
Question 8
Seasonal fruits are made into jam so people can eat them all year. Which importance of preservation is this?
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C
Preserving seasonal fruits gives a continuous supply of out-of-season food.
Section B: structured questions
31 marksAnswer all questions. Circle the answer or write it in the space.
9
Question 9
Diagram 1 shows bread that was kept for two weeks.
[1 mark]
(a)What are the black spots on the bread called?
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[1 mark]
(b)Name the microorganisms that cause this.
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[1 mark]
(c)State one other characteristic of spoilt bread or rice.
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Any 1 points
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10
Question 10
State whether each is a growth factor of microorganisms.
[1 mark]
(a)Water
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Yes
[1 mark]
(b)Suitable temperature
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Yes
[1 mark]
(c)Sunlight on the food only
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No
[1 mark]
(d)Suitable acidity
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Yes
11
Question 11
Match each food with the best preservation method.
[1 mark]
(a)Fresh milk heated at 72 °C for 15 seconds and cooled to 4 °C
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Pasteurising
[1 mark]
(b)Fish smeared with a large quantity of salt
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Salting
[1 mark]
(c)Apples coated with wax
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Waxing
12
Question 12
Aiman dried 150 g of fresh chillies under the Sun. Diagram 2 shows the mass of the chillies (practice numbers, not from the book).
[1 mark]
(a)What is the mass of the chillies on day 7?
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[1 mark]
(b)How much mass did the chillies lose in 7 days?
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[1 mark]
(c)Make an inference about why the mass decreased.
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[1 mark]
(d)Which growth factor of microorganisms is removed?
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13
Question 13
Chilli paste is made by blending chillies with water and oil, then boiling it in a wok until thick.
[1 mark]
(a)State the preservation method used.
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[1 mark]
(b)Why is the boiled paste kept in a container with a lid?
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[1 mark]
(c)How does boiling help to preserve the paste?
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14
Question 14
A fish is cleaned, smeared with a large quantity of salt and dried under the Sun for one week.
[2 marks]
(a)Name the two preservation methods used.
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[1 mark]
(b)Why is a large quantity of salt used?
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[1 mark]
(c)Give another food that can be preserved by combining methods.
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Any 1 points
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15
Question 15
State one importance of food preservation technology for each situation.
[1 mark]
(a)Coconut milk products are packed and sent by container ship to other countries.
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[1 mark]
(b)Leftover beef rendang is dried to make beef floss.
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[1 mark]
(c)Canned sardines take up little space in the cupboard.
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16
Question 16
Puan Anis has a lot of fresh mackerel and wants to keep it for a few weeks. She has no refrigerator. A friend suggests pickling the fish with salt and cooking oil.
[1 mark]
(a)State the purpose of salt.
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[1 mark]
(b)State the purpose of cooking oil.
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[2 marks]
(c)Explain why the fish can be stored for a long time.
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17
Question 17
A fruit seller wants to sell lychees in a supermarket far away. The fruit is soft and spoils in two days.
[1 mark]
(a)Suggest one preservation method for the lychees.
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Any 1 points
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[2 marks]
(b)Explain how the method you chose helps.
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