Obami | Digital Stakeholder Experiences

SECTION A - Answer ALL the questions in this section. (50 marks)

QUESTION 1

1.1

Marks: 20

Question 1:

The distribution of organisms is known as …

Your Answer:

biochemistry

biogeography

archaeology

palaeontology

Question 2:

Which ONE of the following (see attached resource) CORRECTLY describes the cells produced by meiosis?

Attached Resource:

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Your Answer:

Question 3:

Study the following statements:

(i) Organisms in a population show a great deal of variation.

(ii) Characteristics are passed on from parents to offspring.

(iii) If an organism uses an organ frequently it becomes more developed.

(iv) A large number of offspring are produced, but only few survive.

Which ONE of the following combinations refers to observations upon which Darwin based his theory?

Your Answer:

(i), (ii), (iii) and (iv)

(i), (ii) and (iii) only

(i), (ii) and (iv) only

(i), (iii) and (iv) only

Question 4:

Study the following list of molecules:

(i) Sugar
(ii) Phosphate
(iii) Nitrogenous base
(iv) Amino acid

Which ONE of the following combinations represents components of a nucleotide?

Your Answer:

(i), (ii) and (iv) only

(i), (ii) and (iii) only

(i), (ii), (iii) and (iv)

(ii), (iii) and (iv) only

Question 5:

Four different phenotypes are possible in the F1-generation if the parents' blood types are …

Your Answer:

B and B.

A and B.

O and AB.

AB and AB.

Question 6:

In humans, brown eye colour is dominant over blue eye colour. A mother with blue eyes had two children, a boy with brown eyes and a girl with blue eyes. The eye colour of the father is ...

Your Answer:

brown, because the allele for brown eye colour is sex-linked.

brown, because at least one of the parents must have brown eyes.

blue, because at least two other members of the family have blue eyes.

blue, because at least one of the parents must be heterozygous for eye colour.

Question 7:

Use the attached resource to answer the next three questions.

One way to measure the resistance of an insect population to an insecticide is to determine the time taken for the insecticide to kill 90% of the population. This is called the resistance factor (RF).
The graph below shows the results from a resistance investigation in a single population. The same amount of each of three insecticides was used.

What is the approximate RF value for insecticide B?

Attached Resource:

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Your Answer:

0,5

1

2

24

Question 8:

Use the resource attached in the question above to answer this question:

Which ONE of the insecticides has the fastest killing action given that the same quantity of each insecticide was used?

Your Answer:

Insecticide A

Insecticide B

Insecticide C

All the insecticides were equally fast

Question 9:

Use the same resource to answer this question:

A general conclusion from the data shown in the graph above, at 30 minutes, is that …

Your Answer:

both insecticide B and insecticide C have been 100% effective.

both insecticide A and insecticide B have been 100% effective.

both insecticide A and insecticide C have been 100% effective.

all the insecticides have been 100% effective.

Question 10:

Numbers 1, 2, 3 and 4 below refer to four populations of frogs. (see attached resource) These populations are represented diagrammatically by circles. Overlapping circles show populations that are capable of interbreeding to produce fertile offspring.

It would be reasonable to conclude that ...

Attached Resource:

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Your Answer:

if populations 2 and 4 were to die out, two different species would remain.

populations 1, 2, 3 and 4 represent four different species.

if population 2 were to die out, two different species would remain.

if population 3 were to die out, only one species would remain.

1.2 - Give the correct biological term for each of the following descriptions. Write only the term as your answer

Marks: 8

Question 1:

The triplet of bases found in a tRNA molecule

Your Answer:

Question 2:

The condition where an organism has more than two complete sets of chromosomes in a cell

Your Answer:

Question 3:

A genetic disorder characterised by the absence of a blood clotting factor

Your Answer:

Question 4:

Organisms that have different alleles at a given locus

Your Answer:

Question 5:

The physical and/or functional expression of a gene

Your Answer:

Question 6:

An arrangement of black bars representing DNA fragments that can be used to determine whether people are related

Your Answer:

Question 7:

All the chromosomes found in a cell except the sex chromosomes

Your Answer:

Question 8:

The biotechnological production of genetically identical offspring

Your Answer:

1.3 - For each of the next 8 questions, indicate whether the corresponding statements 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 in the answer box respectively.

Marks: 16

Question 1:

Match the following

Attached Resource:

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Your Answer:

Question 2:

Match the following.

Attached Resource:

34dd192f-5e2b-4a13-9ae3-f17350be1102.png

Your Answer:

Question 3:

Match the following.

Attached Resource:

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Your Answer:

Question 4:

Match the following.

Attached Resource:

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Your Answer:

Question 5:

Match the following.

Attached Resource:

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Your Answer:

Question 6:

Match the following.

Attached Resource:

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Your Answer:

Question 7:

Match the following.

Attached Resource:

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Your Answer:

Question 8:

Match the following.

Attached Resource:

041ecf1d-8508-459c-9ebb-598b48c621f9.png

Your Answer:

1.4 - A scientist gathered information about the affected and unaffected individuals for a certain genetic disorder. The genetic disorder is caused by a dominant allele. The findings of the scientist are represented in the pedigree diagram below.

Marks: 6

Attached Section Resource:

875c0390-5406-4948-aa93-8308147d2083.jpg

Question 1:

Using the letters R and r to represent the dominant and recessive alleles respectively, state the genotype of individual:

(a) A
(b) D

Your Answer:

Question 2:

What is the percentage chance of individual X having a genetic disorder?

Your Answer:

Question 3:

If individual C marries an unaffected male, state the possible genotype(s) of their offspring.

Your Answer:

SECTION B - Answer ALL the questions in this section.

QUESTION 2

2.1 - Study the diagram below, which shows a section of a DNA molecule during a process taking place in a cell.

Marks: 6

Attached Section Resource:

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Question 1:

Name the process represented in the diagram.

Your Answer:

Question 2:

When exactly will this process take place in a cell?

Your Answer:

Question 3:

Give labels for 1 and 2.

Your Answer:

Question 4:

State TWO ways in which the structure of RNA differs from the DNA structure shown in the diagram.

Your Answer:

2.2 - The diagram below shows a part of the process of protein synthesis.

Marks: 7

Attached Section Resource:

798f1f3c-4be8-42af-97e6-cc4ffdd12030.jpg

Question 1:

Name the stage of protein synthesis represented in the diagram above.

Your Answer:

Question 2:

Identify:

(a) Molecule X
(b) Molecule Y
(c) Structure 1

Your Answer:

Question 3:

The table below shows the DNA base triplets that code for different amino acids found in human proteins. (see attached resource)

Using the information in the table and the diagram above, write down the sequence of the amino acids that correspond with structures 1, 2 and 3.

Attached Resource:

22143e27-bd64-4aba-a36a-fe3a86930875.jpg

Your Answer:

2.3 - The diagrams below show chromosome pair 21 in the nucleus of a cell of the ovary of a woman. The chromosomes are involved in a process that takes place in a phase of meiosis.

Marks: 11

Attached Section Resource:

9b493d4b-96fa-4a06-b66f-2b7d7cf9dd83.jpg

Question 1:

Give labels for A and B.

Your Answer:

Question 2:

Rearrange the letters X, Y and Z to show the correct sequence in which the events take place in this phase.

Your Answer:

Question 3:

Explain why the chromosomes in Diagram X and Diagram Y are different in appearance.

Your Answer:

Question 4:

The diagram below shows the nuclei of the four cells that resulted from meiosis involving the chromosomes in Diagram X above.

a) Explain why nuclei O and P do NOT have chromosomes. (2 marks)

b) Name and explain the disorder that will result if diagram M represents an egg cell that fuses with a normal sperm cell. (3 marks)

Attached Resource:

ab19d4e5-c305-4b9b-8f6d-1a818fed5e86.jpg

Your Answer:

2.4

Marks: 6

Question 1:

When flies with grey bodies were crossed with flies with black bodies, all the offspring in the F
1 had grey bodies.

Use the letters G and g to represent a genetic cross to show the F2 genotypes and phenotypes if the F1 were interbred.

Your answer: Resource(s)

QUESTION 3

3.1 - Read the extract attached below.

Marks: 12

Attached Section Resource:

72b30143-da69-4c66-8446-e274d97496d3.jpg

Question 1:

What is meant by the term genome referred to in the extract?

Your Answer:

Question 2:

State ONE way in which the genetic engineering described in the extract differs from selective breeding.

Your Answer:

Question 3:

Give ONE reason why the products of genetic engineering must undergo many tests before they can be sold.

Your Answer:

Question 4:

Explain the value of growing herbicide-resistant crops.

Your Answer:

Question 5:

State THREE advantages of genetic engineering in crop production other than those mentioned in the extract above.

Your Answer:

Question 6:

Give a reason why seed companies insist that they must have the exclusive rights to the selling of seeds.

Your Answer:

3.2 - Gregor Mendel conducted breeding experiments with pea plants to study the inheritance patterns of four different traits (plant height, seed shape, seed colour and seed coat colour).

Marks: 11

Attached Section Resource:

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Question 1:

What is the expected phenotypic ratio for a trait involving two heterozygous parents?

Your Answer:

Question 2:

From the results, calculate X and Y. Also state which trait provided a ratio closest to the expected phenotypic ratio mentioned in QUESTION 3.2.1. Show ALL working.

Your Answer:

Question 3:

Give a possible reason why the ratio selected in the above question was closest to the theoretical ratio.

Your Answer:

Question 4:

Using the results, state whether the allele for round seeds or for wrinkled seeds is dominant.

Your Answer:

Question 5:

State TWO factors that Mendel controlled during these breeding experiments.

Your Answer:

Question 6:

Write down Mendel's law of segregation.

Your Answer:

SECTION C - Answer ALL the questions in this section.

QUESTION 4

Attached Section Resource:

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4.1 - Use the attached resource below to answer the questions that follow:

Marks: 11

Attached Section Resource:

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Question 1:

Draw a line graph to represent the results obtained for the number of seedlings surviving in Group 1.

Your answer: Resource(s)

Question 2:

Identify the dependent variable(s) in the investigation.

Your Answer:

Question 3:

Identify TWO independent variables in this investigation.

Your Answer:

4.2

Marks: 26

Question 1:

Describe how a study of the Y-chromosome provides evidence for the 'Out of Africa' hypothesis.

Your Answer:

Question 2:

Describe how a study of the Y-chromosome provides evidence for the 'Out of Africa' hypothesis.

Your Answer:

Question 3:

Describe the structural changes to the skull that characterise the evolution of modern humans from their ape-like ancestors, and explain the significance of these changes.

Attached Resource:

8b99b8c2-1944-48d8-b20a-645fceb7831e.png

Your Answer: