LIFE SCIENCES - Voortrekker...

GRADE 11

LIFE SCIENCES

JUNE 2019

TOTAL: 150

TIME: 2½ HOURS

This question paper consists of 15 pages.

Life Sciences 2 FS/June 2019 Grade 11 Examination

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INSTRUCTIONS AND INFORMATION

Read the following instructions carefully before answering the questions.

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.

Answer ALL the questions. Write ALL the answers in the ANSWER BOOK. Start the answers to EACH question at the top of a NEW page. Number the answers correctly according to the numbering system used in this question paper. Present your answers according to the instructions of each question. Make ALL drawings in pencil and label them in blue or black ink. Draw diagrams, tables or flow charts only when asked to do so. The diagrams in this question paper are NOT necessarily drawn to scale. Do NOT use graph paper. You must use a non-programmable calculator, protractor and a compass, where necessary. Write neatly and legibly.


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SECTION A

QUESTION 1

1.1 Various options are given as possible answers to the following questions. Choose the answer and write only the letter (A to D) next to the question number (1.1.1 to 1.1.10) in the ANSWER BOOK, for example 1.1.11 D.

1.1.1 Nutrition in humans includes THREE processes namely … A

B C D

secretion, digestion and absorption. ingestion, digestion and secretion. secretion, digestion and excretion. ingestion, digestion and absorption.

1.1.2 Excess amino acids are converted into urea by the …

A B C D

heart. pancreas. liver. kidney.

1.1.3 A person who has had his gall bladder removed may be expected to

have some difficulty in the …

A B C D

digestion of fat. excretion of urea. storage of glycogen. absorption of minerals.

1.1.4 A biologist discovered a new living cell with a distinct cell wall but with no definite nucleus. The cell is likely to be a/an …

A B C D

plant cell. virus. bacterium. animal cell.

1.1.5 Which characteristic does viruses have in common with the cells of

living organisms?

A

B C D

Viruses contain a nucleus and organelles Viruses produce their own food Viruses contain nucleic acids such as DNA or RNA Viruses can reproduce outside the cells of living organisms


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1.1.6 The cycle shows a simplified version of two processes in plants.

A + B represent H2O and CO2 respectively.

Which ONE of the following combinations is correct?

A 1: photosynthesis

2: respiration and P + Q: water and carbon dioxide

B 1: respiration

2: photosynthesis and P + Q: water and carbon dioxide

C 1: photosynthesis

2: respiration and P + Q: glucose and oxygen

D 1: respiration

2: photosynthesis and P + Q: glucose and oxygen

1.1.7 Which ONE of the following organisms has a closed blood system?

A

B C D

Flatworms Insects Sponges Earthworms

1.1.8 A destarched plant is one which …

A

B C D

has had its starch removed by alcohol. cannot form starch. has been left in the dark for some hours. can only form sugars, not starch.

1.1.9 Which ONE of the following methods should be used to extract

chlorophyll from a leaf? Boil the leaf in …

A

B C D

pure water. iodine solution. diluted hydrochloric acid. ethanol.

1

P + Q

2

A + B


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1.1.10 In plant cells, the site of photosynthesis is the …

A

B C D

cytoplasm. chloroplast. mitochondrion. nucleus. (10 x 2)

(20)

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 1.2.7) in the ANSWER BOOK.

1.2.1

1.2.2 1.2.3 1.2.4 1.2.5 1.2.6 1.2.7

The protein substances which act as catalysts and control the rate of chemical reactions in the alimentary canal. An internal, fluid filled cavity in triploblastic animals that separates the digestive tract and the body wall Animals that are irregularly shaped A term referring to all biochemical processes in living cells The kind of skeleton that results from muscles working against fluid in body cavities The most advanced phylum in the animal kingdom A microscopic organism that has flagellums

(7 x 1)

(7)

1.3 Indicate whether each of the descriptions 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 1.3.3) in the ANSWER BOOK.

COLUMN I COLUMN II

(6)

1.3.1 Vascular tissue A: B:

Xylem Phloem

1.3.2 Naked seeds A: B:

Angiosperms Gymnosperms

1.3.3 May cause diseases A: B:

Viruses Bacteria

(3 x 2)


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1.4 The diagram below shows a slice of bread that was left in a plastic bag for two weeks.

1.4.1 Give labels for A, C and D. (3)

1.4.2 After two weeks black patches were found on the bread. Name the

micro-organism that formed these patches.

(1)

1.4.3 List THREE conditions needed for the micro-organism, mentioned in QUESTION 1.4.2. to grow on the bread.

(3)

1.4.4 One of the general characteristics of this organism is that it cannot

produce its own food. What is this type of nutrition called?

(1) (8)

Spores on bread germinate

D

A

B

C


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1.5 Study the following phylogenetic tree that shows the relationship between different groups of plants.

3

1.5.1

Identify the plant groups under which A, B, C and D are classified. (4)

1.5.2 Which one of A, B, C or D:

(a) Does not depend on water for sexual reproduction (1)

(b) Is regarded as a thallus (1)

1.5.3 Give a reason for your answer to QUESTION 1.5.2 (b)

(1)

1.5.4 Why are vascular plants able to grow taller than nonvascular plants? (2) (9)

TOTAL SECTION A: 50

A B C D

430 million years ago





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SECTION B QUESTION 2

2.1 Read the following extract and answer the questions that follow.

Living organisms use lots of different strategies for producing offspring, but most strategies fall into the categories of either sexual or asexual reproduction. Sexual and asexual reproduction have both advantages and disadvantages. Asexual reproduction involves one parent and produce offspring that are genetically identical to each other and to the parent. Sexual reproduction involves two parents and produce offspring that are genetically unique. Sexual reproduction also involves the production of haploid gametes by meiosis.

2.1.1 Why do living organisms reproduce? (1)

2.1.2 Offspring formed by asexual reproduction can be referred to as

clones. Quote one statement from the extract that supports this.

(1)

2.1.3 How does the offspring produced by sexual reproduction compare to the parents?

(1)

2.1.4 How does each of the following organisms reproduce?

(a) Bacteria (b) Ferns

(1) (1)

2.1.5 Which type of reproduction contribute to the evolution of species?

(1)

2.1.6 Meiosis is the type of cell division that produces gametes. Mention ONE of the two gametes that are formed during meiosis.

(1) (7)


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2.2 The diagram below represents an investigation done by grade 11 learners.

2.2.1 What is the aim of this experiment? (1)

2.2.2 Identify parts A and B. (2)

2.2.3 Name the important external factor which must be present for the

investigation to be successful.

(1)

2.2.4 Explain TWO precautionary measures to take into consideration when conducting the investigation.

(4)

2.2.5 How could the learners determine whether the gas bubbles are oxygen?

(2)

2.2.6 The experiment was conducted in sunlight. Explain the effect on the results if it was placed in a dark cupboard?

(2) (12)

Gas bubbles

Water

Pond weed

A

B


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2.3 Study the diagram of an investigation done in class.

2.3.1

Write a scientific question for this investigation. (2)

2.3.2

What is the purpose of each of the following:

(a) (b)

Rubber stoppers Clear lime water

(1) (1)

2.3.3

Why do we use germinating seeds?

(2)

2.3.4

Provide a positive result for this investigation. (1) (7)

Rubber stopper

Test tube

Germinating seeds

Glass wool

Clear lime water


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2.4 A person runs up a small hill. The graph below shows the rate at which lactic

acid accumulates in the body while the person is running.

2.4.1 What is the relationship between the amount of accumulated lactic

acid and the time spent running?

(2)

2.4.2 How much lactic acid was there in the person’s body at the third minute?

(1)

2.4.3 Under what circumstances is lactic acid formed? (1)

2.4.4 Name the process that results in the formation of lactic acid. (1)

2.4.5 When the person stops running, most of the lactic acid is removed from the blood and muscles and is eventually converted into various substances as shown below:

PERCENTAGE OF LACTIC ACID CONVERTED

Into GLYCOGEN 20 %

Into CARBON DIOXIDE and WATER 60%

Into GLUCOSE 4%

Into PROTEIN 8%

Calculate the percentage of lactic acid that is not converted into

other substances. SHOW all your calculations.

(2) (7)

2.5 Tabulate THREE differences between photosynthesis and cellular respiration (7)

TOTAL QUESTION 2: 40

0

50

100

150

200

250

2 4 6 8 10

La

cti

c a

cid

(m

g)

Time (minutes)

Accumulation of lactic acid in the body when running up a hill for 10 minutes


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QUESTION 3

3.1 Read the following extract.

Scientists wanted to investigate the effectiveness of garlic in killing bacteria.

They:

Prepared three petri dishes with agar and stored it in a refrigerator

Removed the petri dishes from the refrigerator to allow them to reach

room temperature

Prepared three test tubes and labelled them A, B and C

Measured and mixed the contents of the test tubes as follows:

Test tube

Contents of the test tubes

100 ml milk

5 ml E. coli bacterium

Garlic extract

A x x

B x

C

The scientists then:

Labelled three petri dishes also A, B and C

Removed the lid in petri dish A and used a syringe to extract 10 ml of the

sample from the test tube A and placed it on the centre of petri dish A.

In the same way, using a new syringe extracted a 10 ml sample from

test tube B and placed in petri dish B

Repeated the procedure for petri dish C

Replaced the lids of the petri dishes and they were stored in a cool and

shaded place

THE WONDERS OF RAW GARLIC! Garlic is known to have the ability to fight bacteria and viruses. It is known to be effective against a wide range of bacteria and has the ability to combat the common cold. The antimicrobial substance in garlic is called allicin. To maintain the antibacterial properties of garlic, it must be consumed or applied as raw garlic because cooking will destroy the allicin. Adapted from: https://en.wikipedia.org/wiki/Allicin

https://en.wikipedia.org/wiki/Allicin


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The diameter of the E. coli colony was measured every day for 5 days and recorded in the table below:

Petri dish Diameter of bacteria colony (mm)

Day 1 Day 2 Day 3 Day 4 Day 5

A 0 1,7 3,0 4,6 7,1

B 0 4,2 8,4 15,1 36,5

C 0 0 0 0 0

3.1.1 State the following for the investigation:

(a) (b) (c)

The independent variable

The dependent variable Two variables that should be kept constant

(1) (1) (2)

3.1.2 Use the information from the table to draw line graphs, on the same

system of axes, showing the results of petri dish A and B.

(6)

3.1.3 Explain why the petri dishes were kept in the fridge before the start of the experiment.

(2)

3.1.4 Explain the results obtained in petri dish C. (3) (15)

3.2 The diagram below shows the structure of a flower.

3.2.1 Name the function of part A.

(1)

C

B A

D


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3.2.2

Use LETTERS and the NAMES of parts to explain why fertilisation takes place right after pollination.

(6)

3.2.3 How does a spore differ from a seed?

(2)

3.2.4 Why do the reproductive structures of grasses differ from that of the flower in the diagram?

(1) (10)

3.3 Study the following diagram and answer the questions that follows.

3.3.1 To which phylum does the organism belong to? (1)

3.3.2 What type of symmetry does this organism have? (1)

3.3.3 Name ONE major disadvantage of radial symmetry. (1)

3.3.4 Name TWO methods of locomotion made possible by cephalisation in

this organism.

(2) (5)

3.4 Discuss TWO ways in which invertebrates play a role in agriculture. (6)

3.5 Use a labelled diagram to demonstrate a triploblastic plan in animals. (4)

TOTAL QUESTION 3: 40

TOTAL SECTION B: 80


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SECTION C

QUESTION 4

Homeostatic control of blood sugar levels in the human body involves the role of hormones. Describe how the human body regulates the blood sugar levels. Also mention the causes and symptoms of diabetes mellitus which results from an inability of the body to control the glucose concentration.

Content: Synthesis:

(17) (3) (20)

NOTE: NO marks will be awarded for answers in the form of tables, flow charts or

diagrams.

TOTAL SECTION C:

GRAND TOTAL: 20

150

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