KNEC KCSE BIOLOGY TOPICAL QUESTIONS AND ANSWERS

The set-up below illustrates a procedure that was carried out in the laboratory with a leaf plucked from a green plant that had been growing in sunlight.

(i) What was the purpose of the above procedure?
(ii) Give reasons for carrying out steps A, B and C in this procedure.
A
B
C
(iii) Name the reagent that was used at the step labelled D.
(iv) State the expected result on the leaf after adding the reagent named in (iii) above.

ANSWERS

(i) - Testing a leaf for the presence of starch;
(ii) - A - kill the leaf/break down cells/stop enzymatic activity;
B - Removal of chlorophyll;
C - Soften leaf/makes leaf less brittle;
(iii) Iodine solution;
(iv) Areas where starch is present stain blue/blue black;

Comments

K.C.S.E Biology Q & A - MODEL 2011PP1QN15

25/6/2020

Comments

K.C.S.E Biology Q & A - MODEL 2011PP1QN15

Give reasons for carrying out the following procedures when preparing temporary wet mounts of plant tissues.
(a) Making thin plant sections.
(b) Adding water on the plant section.
(c) Placing a cover slip over the plant section.

answers

Comments

K.C.S.E Biology Q & A - MODEL 2011PP1QN11

25/6/2020

Comments

K.C.S.E Biology Q & A - MODEL 2011PP1QN11

State the functions of the following parts of a light microscope.
(a)Fine adjustment knob.
Stage.

answers

(a)Moves the body tube through smaller distances to bring the image/specimen/object into sharper focus;
(b)Platform where specimen (on slide) is placed;

Comments

K.C.S.E Biology Q & A - MODEL 2011PP1QN04

25/6/2020

Comments

K.C.S.E Biology Q & A - MODEL 2011PP1QN04

State one use for each of the following apparatus in the study of living organisms.
(a) Pooter
(b) Pitfall trap

answers

(a) Sucking small insects/animals;
(b) A trap into which small animals fall and get trapped;

Comments

K.C.S.E Biology Q & A - MODEL 2009PP1QN03

23/6/2020

Comments

K.C.S.E Biology Q & A - MODEL 2009PP1QN03

State the functions of the following parts of a light microscope
(a) Objective lens
(b) Diaphragm

ANSWERS

Comments

Give a reason why staining is necessary when preparing specimens for observation under the microscope

21/6/2020

Comments

K.C.S.E Biology Q & A - MODEL 2007PP1QN02

Give a reason why staining is necessary when preparing specimens for observation under the microscope

ANSWER

It is adding a dye to the specimen to make the feature clearer and distinguishable.

Comments

Other than having many features in common, state the other characteristics of a species

16/6/2020

Comments

K.C.S.E Biology Q & A - MODEL 2001PP1QN01

Other than having many features in common, state the other characteristics of a species

ANSWERS

Interbreed to produce fertile/ viable offspring

Comments

Forward>>

Name the part of a light microscope used to bring an image of a specimen into sharp focus.

Name the part of a light microscope used to bring an image of a specimen into sharp focus.

What is meant by the term irritability?

What is meant by the term irritability?

K.C.S.E Biology Q & A - MODEL 2011PP2QN01

K.C.S.E Biology Q & A - MODEL 2011PP2QN01

K.C.S.E Biology Q & A - MODEL 2011PP1QN15

K.C.S.E Biology Q & A - MODEL 2011PP1QN15

K.C.S.E Biology Q & A - MODEL 2011PP1QN11

K.C.S.E Biology Q & A - MODEL 2011PP1QN11

K.C.S.E Biology Q & A - MODEL 2011PP1QN04

K.C.S.E Biology Q & A - MODEL 2011PP1QN04

K.C.S.E Biology Q & A - MODEL 2009PP1QN03

K.C.S.E Biology Q & A - MODEL 2009PP1QN03

Give a reason why staining is necessary when preparing specimens for observation under the microscope

Give a reason why staining is necessary when preparing specimens for observation under the microscope

Other than having many features in common, state the other characteristics of a species

Other than having many features in common, state the other characteristics of a species

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