.4•..",..'~(,

~UNIVERSITY OF

KWAZU LU- NATAL

UNIVERSITY OFKWAZULU-NATAL

FACULTY OF EDUCATIONSCHOOL OF SCIENCE, MATHEMATICS & TECHNOLOGY

EDUCATIONEdgewood Campus

BACHELOR OF EDUCATION

EXAMINATIONS - JUNE 2010

ModuleTitle Natural Science 110

2.5 Hours

Dr J ColemanMs R Somaru

Code

Marks

EDNS110 EC

150Duration

InternalExaminers

External Examiner Dr R Mudaly

Instructions to candidates:

This examination paper consists of 18 pages (excluding the cover page)and 14 questions. Please check that your question paper is complete.

Answer all questions in your answer book.

You may make use of a calculator.

QUESTION 1

Choose the most correct alternative of those given and write the correspondingletter on your answer sheet.

1.1 Orb web spiders, found throughout South Africa, are known for their intricatewebs. These spiders belong to the Phylum ...

a. Arthropodab. Annelidac. Molluscad. Cnidaria

1.2 The characteristic feature of the gymnosperm clade of plants is ...a. production of sporesb. production of flowersc. lack of true rootsd. production of cones

1.3 Bacteria belong to the Kingdom ...a. Protistab. Animaliac. Plantaed. None of the above

1.4 Insects excrete nitrogenous wastes in the form of ...a. ammoniab ureac. uric acidd. ammonium ions

1.5 The risk of suffering from cardiovascular disease may be reduced by avoidingthe following in one's diet:a. Saturated fatsb. Unsaturated fatsc. Plant oilsd. Vegetables

1.6 The most important factor that usually determines the kind of biome thatdevelops in an area is:a. windb. firec. predationd. climate

1

1.7 One of the following combinations is directly involved in the digestion ofstarch, fats and protein:a. carbon dioxide and enzymesb. water and carbon dioxidec. enzymes and waterd. water and oxygen

1.8 The following are all final products of hydrolysis:a. cellulose, fatty acids, glycerolb. sucrose, glycogen, amino acidsc. glucose, amino acids, glycerold. fatty acids, glycerol, proteins

1.9 The final acceptor of hydrogen removed from an organic molecule duringaerobic respiration is:a. oxygenb. waterc. carbon dioxided. NADP

1.10 The main function of co-enzymes during cellular respiration is to:a. convert glucose into glycogenb. serve as hydrogen acceptorsc. combine with oxygen to form carbon dioxided. form an enzyme-substrate complex

(20)

2

SECTION B

QUESTION 2

A c

E F

6 tree organisms

2.1 Complete the branched key, by filling in the appropriate terms whichcorrespond to the letters a - d in the key. 4

2.2 Use the key to identify the tree organisms A to F. 6

(10)

3

QUESTION 3

3.1 Study the diagram below of structures involved with the cardiovascularsystem and answer the questions that follow.

#------- spinal cord

~.-+-~----------A

B

CI

HD (valve)

E (valve)

F

G

a. The nerve labeled A speeds up the heartbeat. Name this nerve. 1b. Label the structures of the heart B to I. 8

4

3.2 Study the table below and answer the questions that follow.

ArteryArteriole

CapillaryVenuleVein

OAem30.0 prn

8.0 prn20.0 prn0.5 em

40-1010-0.1

less than 0.1less than 0.3

0.3-5

Vessel Diameter of lumen Rate of blood flow! em 5-1

a. Describe the general relationship between the rate of blood flow and thediameter of the lumen of the vessel. 2

b. The rate of blood flow in the veins is slow. What prevents the blood inthe veins flowing backwards? 1

c. In which artery in the human body would you expect the blood pressureto be the greatest? 1

(13)

5

QUESTION 4

4.1 We lose a lot of water when we exercise. The amount of water in our bloodcan therefore become lower than normal. The flow diagram shows how theamount of water in our blood is controlled when this happens. Study thediagram and answer the questions that follow.

Cerebrum

B---~././

4.1 Give labels for regions A to F on the diagram. 64.2 Give the letter of the region in which most reabsorption takes place. 14.3 Give the letter of the region in which filtration takes place. 14.4 Name the hormone released by A that acts on region F. 14.5 Write down the letters (i), (ii) and (iii) in your answer book. In each case,

choose either the word MORE or the word LESS to make the followingsentences correct.

The hormone from gland A makes the tube F (i) MORE/LESS permeable sothat (ii) MORE/LESS water is conserved by the body. Therefore (iii)MORE/LESS water gets excreted. 3

6

4.6 Desert rats are small mammals that can live for long periods on' dry foodand no drinking water. They have a number of adaptations to allow themto survive these conditions. The diagrams below are sections through thekidneys of two different rats, a desert rat and a laboratory rat.

A--+-

nephron

c

B

Rat 1 Rat 2

Is the desert rat Rat 1 or Rat 2? Explain how the kidney that you havechosen is related to survival in a very dry environment. 3

(15)QUESTION 5

5.1 Study the diagram below of a section through the female reproductive tract.

A

B

-rt7t----__ C

D

E

a. Label parts A-E. 5b. Write the letter which represents the part where fertilization occurs. 1c. Write the letter which represents the part where implantation occurs. 1

7

5.2 The diagram below shows events that take place in the human femalereproductive cycle. Answer the questions that follow.

concentrctions ofFSH and LHin blood

i...LH/, "

/ I \"/ I \

/ \ I Ic.:::.... c.-=-=~_..:::/::.-..,.; .....__ 1 ~ _

FSH

concentrations ofoestrogen andprogesterone inblood

I I: oestrogen :I /~' I:.,../ 1,

_'f"" I ,---- I I ..•.•"

14I10

21II

II

i .~ I I ~ II I I Io I I I

~

mens=. I I I II I 0I

I uterus I

A

a. Provide labels for structures labeled A, Band C in the diagram above(B refers to an event). 3

b. From which cells is the hormone oestrogen secreted? Provide evidencefor your answer from the diagram. 3

(13)

8

QUESTION 6

The figure below shows when each vertebrate group arose in the geologicaltimescale. The widths of the columns indicate the number of species in eachgroup. The dotted lines suggest possible evolutionary relationships. Study thefigure and answer the questions that follow.

VERTEBRATE FOSSILS

" -'c~··········/

.: B..,,'(c

.. 'i.....iD

6.1 According to the figure which group is the oldest? 16.2 At present which class has the greatest number of species? 16.3 What does the figure tell you about the changes in abundance of

amphibians from the Carboniferous to the Jurassic Periods? 26.4 When were the reptiles at their most dominant: 100mya or 300mya? 16.5 Name the type of vertebrate that began evolving at the time when most

reptiles became extinct? 1

(6)

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QUESTION 7

The series of figures below, A, 8, C, 0 and E, illustrate a particular process whichoccurs in nature. The figures show a population of young and mature cacti, witheither short roots or long roots. Figure A shows two parent plants whichreproduce in the wet season to give rise to large numbers of offspring.The wet season alternates with a very dry season.-- ~"~

~\",," A

B

1>

The following is a list of terms/phrases, each of which must be matched with oneof the figures A, 8, C, 0 or E above.

Terms/phrases: Survival of the fittestOverproductionAdvantageous characteristics passed on to offspringStruggle for existenceGenetic variation

7.1 Write down the letters A to E one below the other and next to each letter,the relevant term/phrase which applies to it. 5

7.2 Name the phenomenon illustrated by the series of figures above. 1

(6)

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QUESTION 8

8.1 Study the information provided and answer the questions below.

DOT was sprayed over a lake that was infested with mosquitoes. Themosquitoes died while the other plants and animals seemed to be littleaffected. The treatment was repeated over the next few years. Someyears after the first spraying many large fish-eating birds were found to bedead. The concentrations of DOT in the bodies of the animals and plantswere determined experimentally and the results are shown in the table

Organisms Amount of DOT per unit massSmall fish 10 units

Animal plankton 5 units

Plant plankton 1 unit

Large fish 100 unitsFish-eating birds 1600 units

a. Draw a food chain for the lake. 6b. Soon after the introduction of DOT there was a decline in the numbers

of a species of birds of prey.Choose the number of the statement which best explains this:

1. The birds of prey inhaled lethal doses of DOT.2. The birds of prey were particularly sensitive to DOT.3. The birds of prey starved because of the reduction in animal plankton.4. The birds of prey occupied the final position in the food chain. 1

8.2 The Cape Fynbos biome is rapidly declining with less than 10% of theoriginal area remaining. Briefly describe the role of alien invasive plantsas a threat to the biodiversity in the Fynbos. 4

8.3 An area under study in a tropical rain forest contains 60 different species oforganisms. If the biodiversity index is 0.75, calculate the total number oforganisms in this ecosystem. Show your working. 2

(13)

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QUESTION 9

9.1 The pie charts below show the composition of four different types of food.Study them and answer the questions that follow.

Food type I Food type II

Food type III Food type IV

Key:

• -Fats • Proteins L_J -Carbohydrates

a. Which pie chart (I, II, III, IV) shows:(i) The food type that provides the most energy that is immediately

available? Give a reason for your answer. 2(ii) The food type that would lead to kwashiorkor? Give a reason

for your answer. 3b. What is the percentage of fat in food type II? 1

(6)

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QUESTION 10

10.1 Study the illustration below and answer the questions that follow.

enzyme from salivary gland---t-

macromolecule A

enzyme X ----y Ta-i-.d } compound B00

molecules C

Give the name of each of the following:a. macromolecule Ab compound Bc. molecules Cd. enzyme X

10.2 Describe TWO adaptations of a villus for the absorption offood.

1111

4

(8)

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QUESTION 11

A normal blood glucose level is 1,0 rnq/crn" and a normal insulin level is0,5mg/cm3.A group of people with normal levels of blood glucose and blood insulin weretested over a period of 5 hours.The average values were calculated and are indicated in the graph below.Study the graph and answer the questions that follow.

Glucose and insulin levels in blood over time

A/ \ .0, /\ q

I .\ / \~o/ 0' ~o,

--0 0----0' 0

. . . •

1,6.., 1,4E 1,2...:!en§. 1,0CIIIII 0,80(J:::l 0,6'EI't:I0 0,40in 0,2

0,00 2 3 4

Time in hours Key:----*- Blood glucose

--0 --Plasma insulin

5

11.1 What is the glucose level at 3 hours after the start of the investigation? 211.2 Explain the relationship between insulin and blood glucose by referring

to the graphs. 211.3 Explain what causes the blood glucose level to increase between 2 and

3 hours after the investigation started, even though no food was eaten. 2(6)

14

QUESTION 12

The figure below shows the relationship between two biological processes in aplant cell. The arrows indicate the movement of gases into and out of theorganelles. Answer the questions based on the figure.

Organelle X

Pyruvic acid

IZGlucose

iB

A--

"----+2.

Organelle Y

12.1 Name the biological process that takes place in :a. organelle Xb. organelle Y 2

12.2 Give one structural adaptation of organelle X for the processtaking place in it.

12.3 Name the gases represented by:a. 1b. 2

12.412.5

2

2

Name the biochemical processes that occur at A and at Z.Describe the process that takes place in the part labeled B.

27(15)

15

QUESTION 13The following diagram illustrates energy transfer in a living system.Answer the question based on it.

The following is a list of possible answers for the blank spaces labeledA, B, C, 0 and E.:

muscle contractedcarbon dioxide and watermuscle relaxedglucose and oxygenATP

You are required to provide labels for A, B, C, 0 and E by choosing youranswers from the above list. (5)

16

QUESTION 14

14.1 Study the diagram of a generalized cell.

FA

GB

C

e:~.~ ...·0.. ..

. . 0 " o.

D

E

a. Provide labels for parts A-G.b. Provide one function for structures labeled C and E.c. Is this a plant or animal cell?d. Give one reason for your answer above.

7211

17

14.2 The diagram below shows a 3-dimensional view of a plant cell with a"window" cut out to reveal some of its internal structures. Imagine that thecell has been sliced across at lines A, 8 and C. Match these with thediagrams, below this cell's internal structure 1, 2 and 3.

A

B

c

2

3

(14)

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