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2013 Matric Q&a guide

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MARKS: 150 TIME: 2½ hours

Section AQuestion 11.1 Various possible options are provided as answers to the following questions. Choose the correct

answer and write only the letter (A – D) next to the question number (1.1.1 – 1.1.10) in the ANSWER BOOK, for example 1.1.11 d.

1.1.1 The centrosome... a) joins two chromatids together.

b) plays an important role during nuclear division in animal cells. c) is found inside the nucleus. d) contains pigments. 1.1.2 Lamarck’s theory of evolution includes the concept that new organs in a species appear

as a result of... a) an unchanging local environment.

b) the natural variations already present within the population of organisms. c) continual increase in population size. d) the actions of organisms as they use or fail to use body structures. 1.1.3 Which one of the following compounds forms a single RNA nucleotide?

a) Deoxyribose – adenine – thymine. b) Ribose – thymine – deoxyribose. c) Adenine – ribose – phosphate. d) Thymine – ribose – adenine.

1.1.4 If parents have two sons, their chances of having a girl child when they have a third child, theoretically is...

a) 66% b) 75% c) 33% d) 50% 1.1.5 When lions prey on a herd of antelopes, some antelopes are killed and some escape. Which part of Darwin’s concept of natural selection might be used to describe this situation? a) Acquired characteristics. b) Survival of the fittest. c) Reproductive isolation. d) Descent with modification. 1.1.6 In a cross between two heterozygous plants with red flowers 300 offspring are obtained. How many of these will have white flowers? a) 75 b) 150 c) 225 d) 300 1.1.7 The following refer to reproduction in different organisms:

(i) Infertile offspring. (ii) Breed at the same time of the year. (iii) Species-specific courtship behaviour displayed in animals. (iv) Plants adapted to specific pollinators.

Which of the above are reproductive isolating mechanisms? a) (i), (ii), (iii), (iv) b) (i) and (ii) only c) (i), (iii) and (iv) only d) (iii) and (iv) only 1.1.8 A pregnant woman was told by a genetic counsellor that her baby had equal chances of having

blood type A or blood type AB. This means that the genotypes of the woman and her husband must have been... a) IA IA and IB i

b) IA IB and IB i c) IA i and IB IB

d) IA IB and IA i 1.1.9 Which one of the following relates to biological evolution?

a) Modern species evolved from ancestral species. b) Artificial selection is essential for the evolution of species. c) Humans have now progressed from a technological age into an information age. d) Genetic mutations generally cause species to die. (9 x 2=18)

LIFE SCIENCESQUESTIONS

PAPER 1

1.2 Give the correct biological term for each of the following descriptions. Write only the term next to the relevant question number (1.2.1 – 1.2.7). 1.2.1 The position of a gene on a chromosome.

1.2.2 The process of finding out the age of fossils using radioactive elements. 1.2.3 A zygote in which the homologous chromosomes carry contrasting characteristics. 1.2.4 Mutations that are advantageous to an organism and wipe out all other alleles controlling

the same characteristic within the population. 1.2.5 A study of the history of life on Earth through a study of the remains and traces of organisms

that lived a long time ago. 1.2.6 The formation of a new species from an existing species as a result of geographical isolation. 1.2.7 A full set of chromosomes with all the genes of an organism. (7 x 1=7)

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 relevant question number.

Column I Column II

1.3.1 Nitrogen containing base found in DNA. A. AdenineB. Uracil

1.3.2 Hypothesis concerning the distribution of hominids across the Earth.

A. CreationismB. ‘Out of Africa’

1.3.3 The type of gene mutation where only one nitrogenous base is replaced with another.

A. Frame-shift mutationB. Point mutation

1.3.4 Proposed the ideas of use and disuse and the inheritance of modified characteristics to explain evolution.

A. Erasmus DarwinB. Alfred Wallace

1.3.5 Production of new cells. A. MitosisB. Meiosis

(5 x 2=10) 1.4 The diagram below shows the karyotypes in two individuals, A and B. Study the diagrams and answer

the questions that follow:

1 2 3 4 5 6 7

8 9 10 11 12 13 14

16 17 18 19 20 21 XY22

15

1 2 3 4 5 6 7

8 9 10 11 12 13 14

16 17 18 19 20 21 XX22

15

Individual A Individual B

Karotypes of two individuals

1.4.1 What is a karyotype? (2) 1.4.2 Which individual (A or B) is female? (1) 1.4.3 Give one reason for your answer in QUESTION 1.4.2. (2) 1.4.4 Identify which individual (A or B) has an abnormal number of chromosomes. (1) 1.4.5 Name the genetic disorder that the individual in QUESTION 1.4.4 has. (1) 1.4.6 Explain the abnormal chromosome number of the disorder named in 1.4.5 (2) (9)1.5 The following diagram represents structures of a bird and an insect. Study the diagram and

answer the questions that follow.

1.5.1 In what way is the function of the wing of a bird (A) similar to that of an insect (B)? (1) 1.5.2 Are the two wings drawn above homologous or analogous? (1) 1.5.3 Give one reason for your answer in QUESTION 1.5.2. (2) 1.5.4 These two structures are evidence of convergent evolution. Explain this statement. (2) (6) [50]Section BQuestion 22.1 Study the following diagram and answer the questions that follow.

2.1.1 Identify the molecule drawn above. (1) 2.1.2 Give one observable reason for your identification in QUESTION 2.1.1. (2) 2.1.3 Identify the parts labelled A, B, C and E. (4) 2.1.4 Give the letters in sequence that will make up any one nucleotide. (1) 2.1.5 Provide one function of the part labelled D. (2) 2.1.6 What is the process called which sometimes causes a change in the base sequence? (1) (11)

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2013 Matric Q&a guide

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2.2 Study the following diagrams of a cell division process and answer the questions that follow.

A B C

DE

thread

pair of homologouschromosomes

centromerechromosome with two chromatids

chromosome with one chromatid

2.2.1 What type of cell division is occurring in the diagrams above? (1) 2.2.2 Give one reason for your answer in QUESTION 2.2.1 (2) 2.2.3 Provide the names of the different phases represented by the letters A – E. (5) 2.2.4 Using the letters A – E, arrange the different phases in the correct sequence. (1) 2.2.5 How many chromosomes does: (i) cell D have? (ii) each cell in C have? (2) 2.2.6 Name two processes that can take place to bring about variation in this type of

cell division. (2) (13)2.3 Study the diagram below that shows the cloning of a sheep named Dolly.

A body cell is removed from the donor sheep

1.The nucleus of an egg cell from a second sheep is removed and thrown away.

3.

A body cell nucleus is inserted into the egg cell.

4.

A body cell nucleus is removed.

2.

The embryo is cultured.

5.

The embryo is implanted into the womb of another sheep.

6.

First donor Second donor

Dolly is born, a clone of the first donor sheep.

7.

How Dolly was cloned

2.3.1 What process is cloning part of? (1) 2.3.2 Give one reason why it was necessary to remove the nucleus from the egg cell of the

second donor before the sheep could be cloned. (2) 2.3.3 Number 5 on the diagram states that ‘the embryo is cultured’. Which cell division is

responsible for the development of the embryo? (1) 2.3.4 Give one reason why people could be against the process of cloning. (2) (6)Question 33.1 The table below shows how the alleles for colour-blindness are inherited. X and Y represent sex

chromosomes. A carrier does not suffer from colour-blindness but can pass the allele for colour-blindness to their children. Study the table and answer the questions that follow.

Name Of Person Genotype Phenotype

Emily XbXb Colour-blind female

Lindiwe XBXb Carrier female

Nadia XBXB Normal female

Tshepo XbY Colour-blind male

Jeff XBY Normal male

LIFE SCIENCESQUESTIONS

PAPER 1 continued

3.1.1 Is colour-blindness caused by a dominant or recessive allele? (1) 3.1.2 Explain your answer to QUESTION 3.1.1 above. (2) 3.1.3 Provide one reason why colour-blindness is referred to as a sex-linked disorder? (2) 3.1.4 Explain why Tshepo is colour-blind. (2) 3.1.5 Emily and Jeff marry and have two children, a son and a daughter. Show this genetic

cross by using the information in the table above to determine the genotypes and phenotypes of the son and the daughter. (5)

(12)

3.2 Tabulate three differences between natural selection and artificial selection. (7)3.3 The diagram below shows DDT which is a pesticide used on mosquitoes.

Study the diagram and answer the questions that follow.

Before pesticide application After pesticide application

Process A

Reproducti

on

Process B

Firs

t ge

nera

tion

Seco

nd g

ener

atio

n

Survivors of first pesticide application

Survivors of second pesticide application

Resistantmosquito

Susceptiblemosquito

3.3.1 Provide a suitable caption for the above diagram. (2) 3.3.2 What process is represented by: (i) A (ii) B (2) 3.3.3 Describe the composition of the first generation before the pesticide application. (2) 3.3.4 Explain the results obtained after the pesticide application in Process A. (3) 3.3.5 Describe the composition of the survivors in Process B. (2) (18) [30] TOTAL SECTION B: [60]Section CQuestion 44.1 The table below shows the brain volume (in cm3) of 5 hominin species. Study the table and answer the questions that follow:

Hominin species Brain volume (cm3)

1 400

2 500

3 700

4 1200

5 1500

4.1.1 Choose the Hominin species from the list in brackets below that is represented

by numbers 1 - 5 in the above table. (Homo sapiens, Homo erectus, Homo habilis, Australopithecus africanus, Australopithecus afarensis) (5)

4.1.2 Draw a bar graph to represent the data in the table above. Use the names of species on the appropriate axis. (8)

4.1.3 What can you conclude about the brain size of the Australopithecus as opposed to the Homo species? (1)

4.1.4 Which species would be closest to the species Homo neanderthalensis on the graph? (1) 4.1.5 Which hominin species has the: (a) smallest brain? (b) biggest brain? (2) 4.1.6 Name one important difference between the Australopithecus species and the African

apes (e.g. chimpanzees). (2) 4.1.7 Explain one primary characteristic that enables modern man to survive? (1) (20)4.2 Proteins are organic compounds of vital importance to all living organisms. Describe the process

of protein synthesis and explain the biological importance of proteins. Factual Content:17 (20) Synthesis: 3 TOTAL SECTION C: [40]