Feeding the Human Race (OCR GCSE Biology A (Gateway))

Exam Questions

51 mins21 questions
1a
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2 marks

This question is about selective breeding.

The table shows the main steps in the process of selective breeding.

They are not in the correct order.

A

Repeat the process over many generations.

B

Decide which features are wanted.

C

Choose the individuals that have the features that are wanted.

D

Choose the offspring that have the features that are wanted.

E

Allow the individuals to mate.

Write the letters in the boxes below to give the correct order.

Two have been done for you.

q16a-paper2f-june2019-ocrgcsebio
1b
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4 marks

Cows are female and are used by farmers to produce milk.

Bulls are male.

Look at the details of different varieties of cows and bulls.

Variety

Milk production

Aggressive

Cow A

thin and watery

no

Cow B

medium yield and creamy

no

Cow C

medium yield and creamy

yes

 

Bull A

mother produced high yield

yes

Bull B

mother produced high yield

no

Bull C

mother produced low yield

no

A farmer wants to produce cows that produce a high yield of creamy milk.

He does not want his animals to be aggressive.

Suggest which cow and bull he should choose to mate with each other.

Explain your answer.

cow .............           ×             bull .............

explanation ....................................

1c
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3 marks

The graph shows the number of cows and the yield of milk per cow on farms in the USA since 1985.

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(i) Describe the relationship between number of cows and yield of milk shown in the graph.

 [1]

(ii) Suggest two reasons for the relationship shown in the graph.

1 .........................................
2 ..........................................

[2]

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2a
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1 mark

Over the whole world the demand for food to feed humans is increasing.

Describe why is there an increasing demand for food.

2b
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6 marks

Genetic modification (GM) is one method that humans are using to try and produce more food.

(i) What is genetic modification?

 [2]

(ii) Scientists can use GM to alter the features of crops.

One feature is crop yield.

Suggest two other features of crops they could change.

1 ....................................................
2 .....................................................

[2]

(iii) In a recent survey 200 people were asked about GM crops.

The people surveyed were shown six statements. Three were negative statements and three were positive statements.

They were asked to choose one statement they agreed with.

These are the results.  

 

Statement

Number of people
choosing statement

Negative

GM crops are not safe enough to use.

42

Growing GM crops does more harm than good.

32

Growing GM crops tampers with nature.

22

Positive

Growing GM crops can prevent people being hungry.

35

Eating GM crops has very little risk to consumers.

35

Growing GM crops can make food more nutritious.

34

Calculate the percentage of people in the survey that have a negative opinion of genetic modification.

Percentage = .................................... % [2]

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3a
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4 marks

In many countries people rely on bananas for food.

Black sigatoka is a disease of banana plants.

It is caused by a fungus.

Explain how the food security/growth of bananas could be improved:

(i) by using fungicide.

[1]

(ii) by using selective breeding.

 [3]

3b
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2 marks

Higher Tier Only

Scientists have been investigating the conditions needed for the fungus to grow.

They compiled this data.

 

Conditions needed for fungus to grow

Temperature in oC

Percentage humidity (%)

Grows well

25 - 28

>90

Some growth

20 – 25 or 28 - 35

90 - 80

Will not grow

< 20 or >35

<70

Write in the boxes how well the fungus will grow in these conditions.

25 oC and a humidity of 85%

 

27 oC and a humidity of 92%

 

3c
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2 marks

Higher Tier Only

Scientists have tried to predict the effect of climate change on the growth of the fungus.

They have used four different predictions for how the climate might change, A, B, C and D.

They then tried different ways of calculating where the fungus cannot grow. Their results are shown in the table.

 

Percentage area of the world where fungus cannot grow (%)

Climate model

1st calculation

2nd calculation

3rd calculation

4th calculation

A

87.6

87.9

87.7

87.8

B

88.4

88.6

89.0

88.8

C

91.1

91.5

91.4

91.3

D

88.4

88.9

89.5

89.2

(i) Which climate model produces the lowest range of results in the four calculations? Choose from A, B, C or D.

 [1]

(ii) At present the fungus cannot grow over 86.4% of the World. What do the calculations predict about the effect of climate change on the fungus?

 [1]

3d
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2 marks

Scientists are developing a genetically engineered banana plant.

This would be resistant to black sigatoka.

Look at the newspaper headline from an African newspaper.

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In Europe, police have been used to guard genetically engineered crops from protesters.

Suggest why the protesters in Europe want to destroy the crops and why the response in Africa is so different.

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4
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8 marks

Higher tier content only

Two scientists discovered a different method of making monoclonal antibodies.

They put genes that code for many different antibodies into viruses. The viruses then make the antibodies on their surfaces.

If an antigen attaches to an antibody, the scientists use the gene for this antibody to genetically engineer bacteria. The bacteria are then used to make large quantities of the antibody.

(i) Describe how scientists could use the antibody gene to genetically engineer bacteria to make many copies of the antibody.

[4]

(ii) Many people would prefer to use antibodies made using bacteria and viruses, rather than the method shown in Fig. 20.2.

Suggest an explanation for this.

[2]

(iii) In 2018, the scientists were awarded the Nobel Prize for their work.

Explain why their work had to be peer reviewed before they were awarded the prize.

[2]

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