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BIOLOGY PRACTICAL QUESTIONS – SOTIK DISTRICT – 1ST EXAM
1. egg albumen
Pineapple juice mixture (10ml) labelled Z
Iodine solution
Ethanol
Distilled water
DCPIP
Benedict’s solution
Source of heat (hot water bath)
Four (4) test-tubes
2. Bougainvillea leaf –P
Kikuyu grass leaf -Q
Hand lens
3. Hand lens
Freshly killed housefly
Safety pin/pair of forceps
1. (a) You are provided with the solution labelled Z. Using the apparatus and the reagents
provided, carry out the tests for the various food substances
Food | Procedure | Observation | Conclusion |
(b) State the organ(s) which produce(s) enzyme(s) which are required to digest the contents
of solution Z completely
(c) Name the end products of digestion of solution Z
(d) Give two functions of the products named in (c) above in the human body
2. You are provided with the specimens P and Q:
(a) (i) What is the mode of nutrition for the organisms represented by the above specimens?
(ii) Give a reason for your answer in (a) (i) above
(iii) Write an equation for the physiological process involved in the mode of feeding in (a)(i)
above
(b) Draw and label specimen P
(c) State three observable differences between specimens P and Q
(d) Name the trophic level of the organisms from which the specimens were obtained
in the ecosystem
(e) Explain the role played by the organisms in the ecosystem
(f) Which features adapt specimen Q to enabling the organism from which it was detached
to live in its habitat?
3. Using a hand lens, study the specimen provided and answer the questions that follow:
(a) Give the phylum and the class to which the specimen belongs
(b) State two characteristics which are unique to members of the class suggested in (a) above
(c) Using the observable features only, explain how the specimen is adapted to living in its
habitat.
SOTIK DISTRICT 2ND EXAM BIOLOGY PRACTICAL MARKING SCHEME (ANSWERS)
1(a)
FOOD | PROCEDURE | OBSERVATION | CONCLUSION |
STARCH | To 2mls of Z is added 2 drops of iodine solution | The colour of the mixture remained brown | The solution does not contain starch |
REDUCING SUGAR | 2ml of solution Z is mixed with 2ml of benedict’s solution and heated | The colour of the mixture turned blue | Absence of reducing sugar |
VITAMIN C | 2ml of DCPIP is placed in a test tube and solution Z is added drop wisely | The DCPIP is decolorized loses its colour | Vitamin C is present |
LIPID | 2ml of solution Z is put in test tube and ethanol added until it clears then distilled water is added | White colour develops | Lipids present |
NB/ -exact quantities must be mentioned
-correct order of chemicals -correct colours
b) Pancreas reject pancrease
c) Fatty acids and glycerols (Reject if one is missing
d)-can be broken down; to liberate energy; for cellular functions
-can be used to synthesize; structural components of the cell; OWTTE
2. a) i) autotrophic (nutrition)- (1mk) Reject. Antotropism
ii) They are green hence has chlorophyll for photosynthesis;
iii) Carbon (iv) oxide+ water sunlight glucose +oxygen
Chlorophyll
6 CO₂+6 H₂O C₆H₁₂O₆+6 O₂
NB.-chemical symbols must be correct
-the equation must be balanced
b) NB.-all rules for drawing apply
-1 mark for accuracy (1×1=1mk)
-max of 3 correctly labelled parts (3×1=3mks)
P | Q |
i)has broad lamina ii)has hairless lamina iii)lamina has network of veins | -has narrow lamina -has hairy lamina -lamina has parallel veins OWTTE |
3. a)Phylum :Arthropoda. Reject. Anthropoda/Arthropod
Class: insecta. Reject insect
b)-the body has 3 pairs of leg (jointed legs/6(jointed legs)
-the body is divided into 3 clear body parts (i.e. head, thorax and abdomen)
Reject if no mention of distinguished parts
ACC. Any other correct feature max
c)-has very large compound eyes; for spotting; food, enemies, mates etc
-has (6) muscular legs; for efficient locomotion; in search of food, mates etc
-proboscis; for efficient sucking of liquid food; OWTTE STK
