Obami | Digital Stakeholder Experiences

SECTION A - Total 50 marks

QUESTION 1

Question 1.1 - Various options are provided as possible answers to the following questions. Choose the correct answer and write only the letter (A to D) next to the question number (1.1.1 to 1.1.10)

Marks: 20

Question 1:

A relationship in which organisms of two species interact and both benefit is known as …

Your Answer:

commensalism

parasitism

predation

mutualism

Question 2:

The social organisation that enhances the survival of a species is …

Your Answer:

external fertilisation

division of labour among members of a colony

symbiosis between members of a species

living together in different habitats

Question 3:

Which of the following will lead to the greatest increase in the amount of CO₂ in an area after cutting down forest trees?

Your Answer:

Planting crops in the same area

Using the cut trees as building material

Introducing animals into the area

Leaving the soil bare

Question 4:

Populations grow exponentially (at a high rate) when ...

Your Answer:

immigration and emigration rates are equal

the death rate remains above the birth rate.

the birth rate remains far above the death rate.

the emigration rate exceeds the immigration rate

Question 5:

A researcher was testing the hypothesis that 'the range of sound frequencies that a person can hear decreases with age'.

Males and females of differing ages were selected and a sound generator that produces sounds of varying frequencies was used.

What was the dependent variable in the investigation?

Your Answer:

Age

Gender (male or female)

The sound generator

The range of frequencies that a person can hear

Question 6:

The table below shows the average height of human males and females, from birth to 24 years.

Age (years)	Average height of human males (cm)	Average height of human females (cm)
0	50	50
4	100	90
8	120	120
12	130	135
16	150	150
20	170	160
24	175	160

From this data, one could reasonably conclude that …

Your Answer:

males and females reach their maximum height at the same age.

females reach their maximum height later compared to males.

males are taller than females at all ages.

male adults are on average taller than female adults.

Question 7:

Population size can be estimated using the formula below:
P = population estimate
M = number of organisms captured and marked
C = number of organisms recaptured (second capture)
R = number of marked organisms in second capture

P = (M*C)/R

In an investigation to estimate the fish population in a certain dam, the following data was obtained:

Fish captured, marked and released = 40
Marked fish in the second capture = 12
Unmarked fish in the second capture = 48

The estimated size of the fish population is ...

Your Answer:

1 920

160

200

100

Question 8:

Population size can be estimated using the formula below:
P = population estimate
M = number of organisms captured and marked
C = number of organisms recaptured (second capture)
R = number of marked organisms in second capture

P = (M*C)/R

In an investigation to estimate the fish population in a certain dam, the following data was obtained:

Fish captured, marked and released = 40

Marked fish in the second capture = 12
Unmarked fish in the second capture = 48

The validity of the investigation could be decreased if the ...

Your Answer:

investigation was repeated and the average estimate calculated.

mark used was harmless to the fish.

second capture was done long after the first capture

owner of the dam did not grant permission for the investigation to be done.

Question 9:

Study the diagram below showing various parameters that influence the size of a population.

Which ONE of the following parameters is indicated by W?

Your Answer:

Migration

Natality

Predation

Competition

Question 10:

The table below shows the birth and death rates of four different countries in a particular year.

Country	Birth rate (per 1 000 of population)	Death rate (per 1 000 of population)
1	16	16
2	50	24
3	40	15
4	42	10

Which country showed the highest population growth in that year?

Your Answer:

Country A

Country B

Country C

Country D

Question 1.2 - Give the correct biological term for each of the following descriptions. Write only the term next to the question number (1.2.1 to 1.2.6)

Marks: 6

Question 1:

The physical count of every individual in a population

Your Answer:

Question 2:

The maximum number of individuals that can be supported by an environment under prevailing conditions

Your Answer:

Question 3:

A group of populations living together in the same habitat

Your Answer:

Question 4:

The structural changes that some insects undergo before they can resemble the adult form

Your Answer:

Question 5:

The structure in angiosperms that develops into a seed

Your Answer:

Question 6:

The structure in a flower that supports the stigma

Your Answer:

Question 1.3 - Indicate whether each of the statements in COLUMN I applies to A ONLY, B ONLY, BOTH A AND B or NONE of the items in COLUMN II. Write A only, B only, both A and B or none next to the question number (1.3.1 to 1.3.7)

Marks: 14

Question 1:

COLUMN I	COLUMN II
Importance of seeds	A: Source of food B: Protect the embryo

Your Answer:

Question 2:

COLUMN I

COLUMN II

Organisms that are able to produce their

own food by means of photosynthesis

A: Decomposers
B: Primary consumers

Your Answer:

Question 3:

COLUMN I	COLUMN II
A type of asexual reproduction in plants	A: Pollination B: Vegetative

Your Answer:

Question 4:

COLUMN I	COLUMN II
Used in the treatment of middle ear infections	A: Cochlear implants B: Grommets

Your Answer:

Question 5:

COLUMN I	COLUMN II
The transfer of pollen from an anther to a stigma of the same flower	A: Cross-pollination B: Self-pollination

Your Answer:

Question 6:

COLUMN I	COLUMN II
Pollination involving flowers with petals that are reduced or absent	A: Insect. B: Wind

Your Answer:

Question 7:

COLUMN I	COLUMN II
Restricts heat loss from the blood	A: Vasoconstriction B: Vasodilation

Your Answer:

Question 1.4 - Study the graph and answer the questions that follow (1.4.1 to 1.4.3)

Marks: 5

Attached Section Resource:

c7c1da1e-4cd6-4072-801d-4c9af557d3b1.png

Question 1:

Name the following phases:

i. A

ii. B

iii. C

Your Answer:

Question 2:

What do the arrows at A represent in the graph?

Your Answer:

Question 3:

What type of growth curve is represented by the graph?

Your Answer:

Question 1.5 - Study the diagram and Match the structures (A to F) with the descriptions (1.5.1 to 1.5.5), for example 1.5.6 G. A letter may be used more than once, or not at all.

Marks: 5

Attached Section Resource:

50f3b37e-fe36-4b33-a289-865af8ba7cdf.png

Question 1:

Where gaseous exchange occurs between the mother and the foetus

Your Answer:

A

B

C

D

E

F

Question 2:

Removes excretory products from the foetus

Your Answer:

A

B

C

D

E

F

Question 3:

Contains strong muscles which will push the foetus out during birth

Your Answer:

A

B

C

D

E

F

Question 4:

Clamped and cut after the baby is born

Your Answer:

A

B

C

D

E

F

Question 5:

Acts as a shock absorber for the developing foetus

Your Answer:

A

B

C

D

E

F

SECTION B - Total 60 marks

QUESTION 2

Question 2.1 - Refer to the diagram below and answer question 2.1.1 to 2.1.4

Marks: 14

Attached Section Resource:

d9d3baaf-3c48-4ab1-9ef2-737ebfd312ec.png

Question 1:

Give labels for each of the following:

a. C

b. D

c. E

d. F

e. G

Your Answer:

Question 2:

Explain ONE consequence for the body if A is damaged.

Your Answer:

Question 3:

Give TWO examples of reflex actions.

Your Answer:

Question 4:

Draw a labelled diagram of neuron B to show its structure.

Your Answer:

Question 2.2 - Refer to diagram below

Marks: 8

Attached Section Resource:

0983f2b4-626c-4c60-b567-b76dd0be6bdf.png

Question 1:

State FOUR planning steps that the learner must consider before the above investigation on wood lice is undertaken.

Your Answer:

Question 2:

For the investigation above, state the following:
(a) Dependent variable
(b) Independent variable

Your Answer:

Question 3:

State TWO factors that should be kept constant during the investigation above.

Your Answer:

Question 2.3 - Refer to the graph to answer the questions that follow.

Marks: 8

Attached Section Resource:

95e050b6-5850-4132-981d-6dac1701699a.png

Question 1:

Explain the difference between a light-adapted and a dark-adapted eye.

Your Answer:

Question 2:

In which type of eye is the relative acuity (sharpness) of vision the greatest at the:
a. Yellow spot
b. Side of the eye at point Y

Your Answer:

Question 3:

Identify region X on the graph.

Your Answer:

Question 4:

Give the reason why the acuity of vision for both types of eye is zero at region X on the retina.

Your Answer:

QUESTION 3

Question 3.1 - Refer to graph below

Marks: 5

Attached Section Resource:

614d0e3c-61c7-4b8a-9de3-a5b9fb83098f.png

Question 1:

Which curve (A or B) represents survivorship in a developing country?

Your Answer:

A

B

Question 2:

Give TWO explanations for your answer to QUESTION 3.1.1. above

Your Answer:

Question 3.2 - Read the passage below and answer the questions that follow.

Marks: 10

Attached Section Resource:

212d87b0-1fea-427a-b98c-62527d9a1ffd.png

Question 1:

What is poaching?

Your Answer:

Question 2:

Give ONE reason stated in the text above for the increase in rhino poaching in South Africa.

Your Answer:

Question 3:

State TWO ways in which Eastern countries use these rhino horns.

Your Answer:

Question 4:

Explain why we should be concerned about the increasing rhino poaching problem in South Africa.

Your Answer:

Question 5:

Explain TWO ways in which the South African government can prevent rhino poaching.

Your Answer:

Question 3.3 - Refer to the table below

Marks: 5

Attached Section Resource:

df0af2ba-57e4-44e6-ab25-4a3cb0ecea23.png

Question 1:

Explain why the shags and the cormorants are not in direct competition with each other, although they feed in the same area.

Your Answer:

Question 2:

Name the phenomenon explained in QUESTION 3.3.1.

Your Answer:

Question 3:

State ONE resource mentioned above for which the two species compete with each other.

Your Answer:

Question 4:

Name the type of competition that occurs between the two species for the resource mentioned in QUESTION 3.3.3

Your Answer:

Question 3.4 - Refer to the diagram and answer question 3.4.1 to 3.4.4.

Marks: 4

Attached Section Resource:

6b1f09f5-564d-43a7-8334-e9918008512c.png

Question 1:

Name the type of succession involving the organisms in the diagram.

Your Answer:

Question 2:

Give a reason for your answer to QUESTION 3.4.1

Your Answer:

Question 3:

Write down the collective term given to the plants in box 2 based on their role in succession.

Your Answer:

Question 4:

State ONE role of the organisms mentioned in QUESTION 3.4.3 in succession.

Your Answer:

Question 3.5 - Refer to the passage below and answer question 3.5.1 to 3.5.3

Marks: 6

Attached Section Resource:

59605e9a-6c4d-47b0-a46f-898cd1c3f055.png

Question 1:

Explain what might happen to the population size of the carnivorous fish that feed on the herbivores if the local seaweeds are replaced by C. taxifolia.

Your Answer:

Question 2:

Suggest a reason why it may not be advisable to use chlorine to kill C. taxifolia.

Your Answer:

Question 3:

Explain a possible disadvantage of introducing sea slugs to control the C. taxifolia population.

Your Answer:

SECTION C

QUESTION 4

Question 4.1 - Refer to attached resource

Marks: 10

Attached Section Resource:

0c428ee7-4e21-433e-8f26-b9a98cce6f95.PNG

Question 1:

State ONE function of the gibberellins that led to the results obtained in the investigation.

Your Answer:

Question 2:

Calculate the difference in the average length of the lateral branches between the plants treated with gibberellins and the plants treated with the paste only on the 8th day after the treatment. Show ALL working.

Your Answer:

Question 3:

State TWO ways in which the reliability of the investigation could be increased.

Your Answer:

Question 4:

Use the results to explain the effect of auxins on the growth of the lateral branches.

Your Answer:

Question 4.2 - Refer to attached resource

Marks: 9

Attached Section Resource:

eeac4532-b92e-4af7-b4aa-1976a2574856.PNG

Question 1:

Draw a histogram using the data in the table above.

[See attached resource above]

Your Answer:

Question 2:

Name the hormone that results in diabetes mellitus when it is deficient.

Your Answer:

Question 3:

Name the organ that secretes the hormone mentioned in QUESTION 4.2.2.

Your Answer:

Question 4:

State TWO other hormones (except the one mentioned in QUESTION 4.2.2) that influence the glucose level of the blood.

Your Answer:

Question 4.3 - Total 20 marks

Marks: 20

Question 1:

Describe the menstrual cycle and how it is influenced by different hormones.

Content: 17 marks
Synthesis: 3 marks

Your Answer: