Instructions to candidates
- Answer all questions in this paper in the spaces provided after each question.
- You are required to spend the first 15 minutes reading the whole paper carefully before commencing your work.
- This paper consists of 4 printed pages. Candidates should check the question paper to ensure all pages are printed as indicated and that no questions are missing.
- Candidates should answer the questions in correct English. Incorrect spellings of especially technical terms may be penalized.
- You are provided with cooking oil, liquids H and E and an Irish potato.
- Label two test tubes A and B. Place 2cm3 of water into each test tube. Add 8 drops of the cooking oil into each test tube. To the test tube labelled A, add 8 drops of liquid H. Shake both test tubes. Allow to stand for 2 minutes.
- Record your observations. (2marks)
Test tube A .........................................
Test tube B ……………………… - Name the process that has taken place in test tube A. (1mark)
- State the significance of the process named in (a) (ii) above. (1mark)
- Name;
The digestive juice in humans that has the same effect on oil as liquid L. (1mark) - The region of the alimentary canal into which the juice named in (a) (iv) above is secreted(1mark)
- Record your observations. (2marks)
- Label one test tube C.
Place 2cm3 of liquid E into the test tube. Add a drop of iodine solution into the test tube.- Record your observation (1mark)
- Suggest the identity of E (1mark)
- Cut out a cube whose sides are about 2cm from the Irish potato provided.Crush the cube to obtain a paste. Place the paste into the test tube labelled C containing E and iodine solution from (b) above. Leave the set up for at least 30 minutes.
- Record your observations. (1mark)
- Account for the results in (c) (i) above. (3marks)
-
- Cut out another cube whose sides are 1cm from the Irish potato provided. Crush the cube to obtain a paste. Use the paste to carry out food test with Benedict`s solution and record the results. (1mark)
- Account for the results in (d) (i) above. (2marks)
- Label two test tubes A and B. Place 2cm3 of water into each test tube. Add 8 drops of the cooking oil into each test tube. To the test tube labelled A, add 8 drops of liquid H. Shake both test tubes. Allow to stand for 2 minutes.
- The diagrams below represents plants , K,L and M. study them carefully and answer the questions that follow
- Giving a reason in each case, classify each plant into its division.
Plant K (2mks)
Division...............................................................
Reason............................................................
Plant L (2mks)
Division.............................................................
Reason............................................................. - Using observable features only, state the subdivision of plant M (2marks)
Sub-division.......................................................................
Reason............................................................................. - Identify the parts labeled P,U,V & Y(4mks)
P ………………………………………………………………………………………………
U ………………………………………………………………………………………………
V ………………………………………………………………………………………………
Y ……………………………………………………………………………………………… - State the functions of part T and state why (d) grows in wet areas. (2 marks)
Function of T........................................................................................................
Reason why (d) grows in wet areas ...........................................................................................................................
- Giving a reason in each case, classify each plant into its division.
- Below are diagrams of part of the urinary system. Examine them
-
- Name the parts labeled A and B in figure 1 (2mks)
A………………………………………………………………………..
B……………………………………………………………………….. - Name the parts labeled V, W, X and Y in figure 11. (4mks)
V…………………………………………….
W…………………………………………….
X…………………………………………….
Y…………………………………………….
- Name the parts labeled A and B in figure 1 (2mks)
- State two adaptations of part labeled W to its function (2mks)
- In the diagram, name the part where;
- Counter current flow occurs (1mks)
- Reabsorption of water occurs (1mks)
- Explain what would happen to the process of urine formation in absence of anti-duiretic hormone (ADH) (3mks)
-
CONFIDENTIAL
Each student will require;
- Scalpel
- Means of timing
- 5ml of Sodium hydrogen carbonate solution labelled H
- 5ml of 10% Starch solution labelled E
- Four labels
- Four clean dry test tubes.
- 4ml of cooking oil in a test tube
- One Irish potato tuber, Solanum tuberosum
- 10ml measuring cylinder
- A dropper
- Ruler
- Spatula
Each student will require access to the following;
- Mortar and pestle
- Iodine solution supplied in a dropper bottle
- Distilled water in a wash bottle
- Benedict`s solution in a dropper bottle
- Source of heat
The photographs should be coloured
MARKING SCHEME
QUESTION 1
-
- Test tube A (1mk)
Oil broken into small/tiny droplets/globules; which are dispersed/spread throughout the liquid//Oil became emusified; Rej. White solution/white ppt/suspension alone
Test tube B (1mk)
Two separate/immiscible layers//oil floats on water/no mixing occured; - Emulsification; (1mk)
- To increases the surface area of fats/lipids for digestion; (1mk)
- Bile (juice); Rej. Pancreatic juice (1mk)
- Duodenum; (1mk)
- Test tube A (1mk)
-
- Blue black; Acc. Black (1mk)
- Starch solution;(1mk)
-
- Blue black colour in C fades/disappeared; Acc. Colour change to light orange/yellow/orange/ brown/purple (1mk)
- Enzyme/amylase; in the potato tissue breaks down/hydrolysed starch; into sugars/maltose; which do not give blue black colour with iodine;(3mks)
-
- Turns from blue to green/yellow/orange/brown colour;(1mk)
- Starch in potato is converted/changed; to maltose/reducing sugar/simple sugar; by enzyme/amylase/maltase;(2mks) OWTTE
QUESTION 2
- K- Pteridophyta; rej wrong spelling (2mks)
Reason - presence of sori
- Leaf modified to a frond
L - Bryophyta (2mks)
Reason - presence of capsules
- Presence of seta
- Presence of rhizoids - Gymnospermatophyta;rej Gymnospermae (2mks)
Reasons -presence of cones (male and female-palm - like leaves - P –sorus; rej sori (1mk)
U- Archegonium; rej Archegonia (1mk)
V-male cone; (s) (1mk)
Y- Seta. (1mk) - T –produce male gametes; sperms /antherozoids (1mk) why D –grows in wet areas to provide moisture for antherozoids to swim to archegonia (to cause fertilisation) (1mk)
QUESTION 3
-
- A-Renal vein (2mks)
B-ureter - V-Glomerulus;
W-Proximal convoluted tubule
X-distal convoluted tubule
Y-Blood capillaries (4mks)
- A-Renal vein (2mks)
- coiled to increase S.A for reabsorption of substance (ii)The tubule is supplied with blood capillaries to transport reabsorbed substances;
-
- Loop of Henle
- Collecting duct/Distal convoluted tubule
- Kidney tubule becomes less permeable to water;les water reabsorbed into blood stream;production of large amounts of dilute urine (thus diuresis)
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