BIOLOGY PRACTICAL QUESTIONS – SOTIK DISTRICT
1. Each candidate should have one fruit of;
- Black jack labeled P
- Tomato (ripe one – money maker variety) labeled Q
- Bean/pea (mature one) labelled R
- Bean/pea (mature one) labelled R
- Sonchus /fleabane/dandelion labeled S
2. Each candidate should have access to :-
- DCPIP solution
- Ethanol
- Benedict’s solution
- Iodine solution
- Hot water bath
- Clean water
N/B Use clean droppers where applicable to minimize contamination of reagents.
3. Each candidate should be provided with;
(i) 4 test-tubes in a test tube rack.
(ii) Razor blade (or they can be asked to bring theirs).
1. You are provided with specimens labeled P, Q, R and S
(a) State the type of fruits represented by each of the specimens
(b) Explain how specimens R and S are adapted to their agents of dispersal
(c) Cut the specimen Q transversely in the middle. Draw a well labeled diagram of the
face of the cut surface of one of the halves
(d) State the placentation of specimen Q
2. (a) Wash of the halves of specimen Q and place it in a mortar and grind it using the pestle to
obtain its juice. Then add clean water enough to fill a test tube and shake. Then decant the
juice into a clean test tube. Using the apparatus and the chemicals provided subject
(b) Explain how digestions of the components of the food sample are digested in the ileum
of a mammal (c) What is the importance of specimen Q in the human diet?
3. The photographs W and Z below are of plants obtained from different habitats 
(a) Suggest the possible habitat of specimen W
(b) (i) Name the structure labeled Y in specimen W
(ii) State the function of the structure named in (b) (i) above
SOTIK DISTRICT BIOLOGY PRACTICAL MARKING SCHEME (ANSWERS)
1. a) SPECIMEN TYPE OF FRUIT
P Cypsella
Q Berry
R Legume
S Cypsella
b) R has two lines of weaknesses (sutures) along which it splits; to release seeds by explosive
mechanism;
Accept Self dopersal for explosive mechanism
Reject self explosion or self explosive mechanism
Agent = 1 mk, adaptation = 1 mk; reason = 1 mk
S is very small; with pappus; making it light; to float easily to be dispersed by wind;
Agent = wind 1 mk Any one adaptive feature & explanation
Adaptation = 1 mk Reason = 1 mk
c)
d) Axile placentation
2. a)
FOOD | PROCEDURE | OBSERVATION | CONCLUSION |
Lipids | 4cm3 of food sample mixed with 4cm3 of ethanol then add clean water( 1 mk) | No change in colour | Absence of lipids |
Reducing sugar | 2cm3 of food sample in mixed with 2cm3 of Benedicts solution and heated in the hot water bath(1mk ) | The colour changes from blue to brown 1mk | Presence of reducing sugar 1 mk |
Ascorbic acid (Vitamin C) | 2cm3 of DCIP is put in a test tube. Add food sample droplisively (1mk) | The DCIP is decolorized (1mk) | Ascorbic acid (Vitamin C) present(1 mk) |
Starch | 2cm3 of food sample placed in a test tube and four drops of iodine solution added (1 mk) | The colour of the solution turned brown 1 mk | Starch is absent 1 mk |
b) Since a carbohydrate is present, maltase; acts on maltose; producing glucose; or lactase;
acts on lactose; into galactose and glucose; i.e. enzymes in ileum; product;
c) Provides simple carbohydrates e.g. glucose which can be broken down in body cells to
liberate energy; or it is a source of vitamin C which is necessary for proper development
of epithelial tissues controlling scurvy; OWITTE Any two fully explained answers
3. a) i) W – Aquatic (water)
ii) Z – Desert or semi- desert or dry land
b) i) Y- Flower
ii) Sexual reproduction Reject reproductive alone
c) Observable features apply i.e. has thick succulent stem; for storage of water; and
respiratory; its leaves are reduced into spines; to lower the SA for transpiration; or for
protection against herbivores
