ls gr. 10 june 2018 replacement...2018/06/10 · 2qo\ gudz gldjudpv wdeohv ru iorz fkduwv zkhq...

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GRADE 10

LIFE SCIENCES

JUNE 2018

TOTAL: 150

TIME: 2½ HOURS

This question paper consists of 11 pages.

Life Sciences 2 FS/June 2018 Grade 10


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 your 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. ALL drawings should be done in pencil and labelled in blue or black ink. Only draw diagrams, tables or flow charts when asked to do so. The diagrams in this question paper are NOT all drawn to scale. Do NOT use graph paper. Non-programmable calculators, protractors and compasses may be used. Write neatly and legibly.



SECTION A

QUESTION 1

1.1 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) on the answer sheet. Example, 1 .1.11. D

1.1.1 The thickened membranes in which chlorophyll molecules are found are the …

A middle lamella

B cristae

C E.R

D Thylakoids

1.1.2 The cell organelle responsible for the yellow colour in autumn leaves, is the …

A mitochondria

B chromoplast

C leucoplast

D vacuole

1.1.3 The type of cell division that results in growth …

A meiosis

B mitosis

C cell differentiation

D mitochondria

1.1.4 Which one of the following is the best description of meristematic tissue?

A transport tissue

B secondary tissue

C strengthening tissue

D undifferentiated tissue

1.1.5 Which of the following is not an example of connective tissue?

A blood

B bone

C epithelium

D cartilage.



1.1.6 In which of the following cells would you expect mitochondria to be most numerous?

A bone cells

B fat storage cells

C muscle cells

D nerve cells

1.1.7 An example of a polysaccharide:

A glucose

B lactose

C fructose

D glycogen

1.1.8 An organic compound lipids monomer …

A saccharide

B 3 glycerol and one fatty acid

C polysaccharide

D amino acids

1.1.9 A deficiency disease as a result of a shortage of Vitamin B.

A Night blindness

B Rickets

C Beri-Beri

D Pellagra

1.1.10 Proteins differ from carbohydrates in that …

A They are not sensitive to temperature

B Some are enzymes

C They all supply the main source of food for energy.

D They all react negatively with Millon’s reagent.

(10x2=20)



1.2 Give the correct BIOLOGICAL TERM for each of the following descriptions. Write down only the term next to the question number.

1.2.1 The carbohydrate that forms a structural component of cell walls. (1)

1.2.2 The chemical reagent used to indicate the presence of starch. (1)

1.2.3 The spontaneous movement of molecules in liquids and gases from a high to

a low concentration. (1)

1.2.4 Projections on the inner membrane of the mitochondrion. (1)

1.2.5 Tissue responsible for secondary thickening in plants. (1)

1.2.6 A tumour that is not cancerous. (1)

1.2.7 A tissue in plants which cell walls are thickened at the corners. (1)

[7]

1.3 State whether each of the phrases in Column I, applies to A only, B only, Both A and B, or None in Column II. Write down A ONLY, B ONLY, BOTH A AND B OR NONE next to the question number.

COLUMN I COLUMN II 1.3.1 Mitosis A. cloning

B. chromosomes 1.3.2 Fighting infection A. leukocytes

B. erythrocytes 1.3.3 Absorption of nutrients A. stomata

B. root hair 1.3.4 Nerve cells A. neuron

B. synapse 1.3.5 Protein synthesis A. ribosome

B. chloroplast 1.3.6 Carbohydrates A. hydrogen

B. oxygen 1.3.7 Mesophyll A. epidermis

B. stomata 1.3.8 Vascular bundles A. xylem

B. phloem [8x2=16]



1.4 Study the diagram of a cell below and answer the question.

1.4.1 Provide labels for A, B, C and D. (4)

1.4.2 State TWO functions of D. (2)

1.4.3 State ONE function of C. (1)

[7]

TOTAL SECTION A=50

SECTION B

QUESTION 2

Study the diagrams and answer the questions that follow.

1. 2. 3.

4. 5.

C

D

A

B



2.1.1 Label structures A, B, C and D. (4) 2.1.2 By making use of NUMBERS ONLY, arrange the phases into the correct sequence. (5) 2.1.3 Write down the number of chromosomes in a daughter cell at the end of the process shown above. (1) 2.1.4 State ONE difference between plant and animal cells with regard to the process taking place at C. (1) 2.1.5 State ONE reason why mitosis is a biologically important process. (1) [12]

2.2 Study the diagrams and answer the questions that follow.

A 'cell' containing a sugar A ‘cell’ containing water

solution placed in a placed in a beaker

beaker with water with a sugar solution

Figure 1 Figure 2

2.2.1 Which physiological process is represented by the diagram? (1)

2.2.2 What is meant by a differentially permeable membrane? (2)

2.2.3 Describe what happens in FIGURE 2 and explain your answer by indicating in which direction the water moves and why. (5)

[8]

Sugar solution

water

Glass beaker



2.3 The table below shows the nutritional value of a certain brand of breakfast cereal. Study the information before answering the questions below.

NUTRITIONAL COMPOSITION OF CEREAL

Ingredients Nutritional Information (Values per 100 g)

Whole rolled oats, roasted wheat flakes, cane syrup, brown sugar, vegetable oil, sun-dried raisins

Energy 2000kJ Protein 12,5 g Carbohydrates 50 g Fats 12,5g Fibre 25 g Cholesterol 0 g

2.3.1 Explain ONE advantage of this cereal having no cholesterol. (1)

2.3.2 The total energy value of a 100 g cereal is 2 000 kJ. The boy requires 5 500 kJ of energy per day. How many grams (g) of cereal does he need to eat in order to obtain this energy (assuming that he does not eat any other foods)? Show your working. (2)

2.3.3 Draw a pie chart to illustrate the relative proportions of protein, carbohydrate, fats and fibre of this 100 g of cereal. (6)

[9]

2.4 An experiment was conducted to investigate the effect of temperature on the activity of enzymes in yeast cells. The activity of the enzyme was measured by the volume of gas bubbles produced as froth in a measuring cylinder containing the yeast cells in glucose solution. Study Figure 1 and Figure 2 that shows the results of the investigation and answer the questions that follow.

Figure 1



The volume of bubbles produced at different temperatures

Figure 2

2.4.1 What volume of bubbles was produced at 45˚C? (1)

2.4.2 At which temperature was the enzymes totally denatured? (1)

2.4.3 Explain what does denatured mean? (2)

2.4.4 Give a hypothesis for this investigation. (2)

2.4.5 Give the:

a. independent variable (1)

b. dependent variable (1)

c. ONE controlled variable (1)

2.4.6 Give ONE way in which we can make this investigation more reliable (1)

2.4.7. Give ONE way in which we can make it more valid. (1)

[11]

TOTAL QUESTION 2= [40]



QUESTION 3

3.1. List FOUR functions of the human skeleton. (4)

3.2 Study the diagram below which shows a section through the arm and elbow joint of a human and answer the questions that follow.

3.2.1 Label structures A , C and D respectively. (3)

3.2.2 Make a labelled drawing of a longitudinal section through a long bone. (6)

3.2.3 State whether the illustration shows part of the axial or appendicular skeleton. (1)

3.2.4 Name two advantages of an exoskeleton. (2)

[16]

3.3 Answer the following questions.

3.3.1 Define the term transpiration. (3)

3.3.2 State four factors that influence the rate of transpiration and explain how these factors will increase or decrease the rate. (8) 3.3.3 Suggest four possible adaptations of the structure of a leaf of a plant to decrease the rate of transpiration. (4) 3.3.4 What is the apparatus called to investigate transpiration? (1)

[16]

3.4 Define the following terms:

a. Cloning (2)

b. Stem cells (2)

c. Tumour (2)

d. Cranium (2)

TOTAL QUESTION 3= [40]

A

B

C

D



SECTION C

QUESTION 4

Describe the absorption of water by a root hair of a plant as well as the lateral movement of the absorbed water from the root hair to the xylem of the root. Also explain the different ways in which the xylem is structurally suited to transport water upwards in plants.

Content: (17)

Synthesis: (3)

NOTE:

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

TOTAL SECTION C: 20

GRAND TOTAL: 150

ls gr. 10 june 2018 replacement...2018/06/10 · 2qo\ gudz gldjudpv wdeohv ru iorz fkduwv zkhq...

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