A group of students set up an experiment to investigate a certain physiological process. The set up was as shown in the diagram below.

3/11/2021

Comments

A group of students set up an experiment to investigate a certain physiological process. The set up
was as shown in the diagram below.

(a) What physiological process was being investigated? (1mk)

Osmosis

(b) (i) State two major observation that was made after some time. (2mks)

Distilled in the Irish potato would reduce in level; (1mk)
Level of concentrated salt solution would increase in the Petri dish(2mks)

(ii) Account for the above observation in b (i) above. (4mks)

Concentrated salt solution in the Petri-dish has higher osmotic pressure than the cells of the Irish potato; these cells lost water to the salt solution by osmosis; these cells become more concentrated and drew water from the neighbouring cells; this process continued until the cells in contact with water in the potato drew it up. (4mks)

(c) State the significance of the biological process involved in the experiment. (1mk)

Support in herbaceous plants
Absorption of water
Opening and closing of stomata
Movement and water between plants
Feeding in sectivorous plants
Folding of leaves of mimosa pudica when touched

Comments

List three characteristics that distinguish arthropods from organisms in kingdom Monera

1/11/2021

Comments

List three characteristics that distinguish arthropods from organisms in kingdom Monera (3mks)

Arthropods are large multicellular organisms;
Arthropods have jointed appendages;
Arthropods body is covered by an exoskeleton;
Arthropods have segmented bodies;
Arthropods exhibited sexual reproduction with an internal fertilization

Comments

The equation below represents a process in a mammalian liver

31/10/2021

Comments

The equation below represents a process in a mammalian liver

(a) Name the process shown by the equation above (1mk)

Deamination;

(b) List down a carbohydrate that is;-

(i) Stored in the mammalian liver (1mk)

Glycogen;

(ii) Found in abundance in mammalian blood (1mk)

Glucose;

Comments

Identify the use of the following apparatus, Bait trap, Specimen bottle, Pitfall trap

30/10/2021

Comments

Identify the use of the following apparatus (3mks)

(i) Bait trap

For attracting and trapping small animals including rats

(ii) Specimen bottle

For keeping collected specimen;

(iii) Pitfall trap

For catching crawling animals;

Comments

State the functions of the following parts in a cell: Nucleolus, Smooth endoplasmic reticulum

30/10/2021

Comments

a) State the functions of the following parts in a cell (2mks)

(i) Nucleolus

Manufacture/synthesis of ribosomes;

(ii) Smooth endoplasmic reticulum

Transport of lipido

(b) Name an organelle that would be found in large numbers in cells of secretory glands (1mk)

Golgi bodies/Golgi apparatus;

Comments

Name two functions of sodium in human body

30/10/2021

Comments

Name two functions of sodium in human body (2mks)

Formation of the harmone thyropine;
Nerve impulse transmission;

Comments

State the role of light in photosynthesis

30/10/2021

Comments

State the role of light in photosynthesis (1mk)

Photolysis/provides energy required for splitting water molecules into hydrogen ions and oxygen gas;

Comments

Classification: Biology Topical Questions and Answers

11/11/2020

Comments

CLASSIFICATION

1. 1995 Q3 P1

State two ways in which some fungi are harmful to man (2 marks)

2. 1995 Q6 P1

The diagram below represents a fern

fern

Name

(a) The parts labelled A and B ( 2 marks)

(b) The division to which the plant belongs ( 1 mark)

Comments

Cell Physiology Topical Questions and Answers

9/11/2020

Comments

CELL PHYSIOLOGY

1. 1989 Q14 P1

The table below shows the concentration of some ions in pond water and in the cell sap of an aquatic plant growing in the pond.

Ions	Concentration in pond water	Concentration in cell
Sodium	50	30
Potassium	2
Calcium	15	1
Chloride	180	200

(a)    Name the process by which the following ions could have been taken up by this plant
(i)     Sodium ions
(ii)    Potassium ions
(b)   For each processes named in (a) (i) and (ii) above, state one condition necessary for the process to take place.

Comments

Nutrition in Plants and Animals Questions and Answers

8/11/2020

Comments

NUTRITION IN PLANTS AND ANIMALS

The diagram below shows chemical reactions I, and II which are controlled by enzymes respectively.

1. 1989 Q1 P1

Name reaction II and enzyme B

Comments

Introduction to Biology Questions and Answers

7/11/2020

Comments

Introduction to Biology

1. 1995 Q 1 P1

Motor vehicles move, use energy and produce carbon dioxide and water. Similar characteristics occur in living organisms yet motor vehicles are not classified as living. List the other characteristics of living things that do NOT occur in motor vehicles.

They reproduce
They grow
They respond to stimuli

Comments

K.C.S.E Biology Q & A - MODEL 2019PP2QN06

2/7/2020

Comments

K.C.S.E Biology Q & A - MODEL 2019PP2QN06

The table below shows the rate of product formation for two enzymes, H and J over a range of pH values

(a) On the same axis, plot graphs of the rate of product formation against pH.
GRAPH PAPER
(b) Account for the rate of product formation for enzyme H between:
(i) pH 1.0 and 3.0
(ii) pH 3.0 and 7.0.
(c) From the graph, determine: .
(i) the pH value at which the rate of product formation of the two enzymes was the same
(ii) the value of the rate of product formation for enzymes H and J at the pH value stated in (c)(i) above
(iii) the optimum pH value for enzyme J
(d) State one variable that may lead to the change in the optimum rate of product-formation of the two enzymes.
(e) Suggest with a reason, the likely part of the human alimentary canal where enzyme H would be found.

answers

(b) (i) Rate of product formation increases with the increase in pH to the optimum then decreases;
   pH 5 is the optimum pH value for activity of enzyme H; between pH 1 and 2 enzyme H/enzyme molecules are activated; Between pH 2 and 3 enzyme H (enzyme molecules) are denatured/destroyed; (. Enzyme is inactivated/ less active for denatured
(ii) Rate of product formation (sharply) decreases with increase in pH; Enzyme H is (not formed by increase in pH hence is denatured); No product forms above pH 4.0 to 7.0; because all enzymes (enzyme molecules) are denatured;
(c) (i) 4.0
   (ii) 15.0 mg/hr
    (iii) 7.0
(d) -Temperature
-Substrate concentration;
-Enzyme concentration;
-Cofactors
-Co-enzymes
-(Enzyme) inhibitors
(e) Stomach;
Acidic medium/Low pH

Comments

State one importance of irritability to living organisms.

2/7/2020

Comments

K.C.S.E Biology Q & A - MODEL 2019PP2QN03

State one importance of irritability to living organisms.

answers

(a) Enable living organisms to avoid dangerous/harmful/hash climatic environmental conditions; Enable living organisms obtain/access favourable environmental conditions (light, water, oxygen,

Comments

Plasmodium vivax and Plasmodiuin ovale are transmitted by a mosquito. State with a reason whether the two organisms can interbreed.

2/7/2020

Comments

K.C.S.E Biology Q & A - MODEL 2019PP1QN24

Plasmodium vivax and Plasmodiuin ovale are transmitted by a mosquito. State with a reason whether the two organisms can interbreed.

answers

(a) they can interbreed; because they belong to the same genus;
They cannot interbreed; because they do not belong to the same species.

Comments

Make a diagram of a simple, bibbed leaf with a serrated margin.

2/7/2020

Comments

K.C.S.E Biology Q & A - MODEL 2019PP1QN21

Make a diagram of a simple, bibbed leaf with a serrated margin.

answers

Comments

<<Previous

​A group of students set up an experiment to investigate a certain physiological process. The set up was as shown in the diagram below.

​(a) What physiological process was being investigated? (1mk)

​(b) (i) State two major observation that was made after some time. (2mks)

​(ii) Account for the above observation in b (i) above. (4mks)

​(c) State the significance of the biological process involved in the experiment. (1mk)

​List three characteristics that distinguish arthropods from organisms in kingdom Monera (3mks)

​(a) Name the process shown by the equation above (1mk)

​(b) List down a carbohydrate that is;-

(i) Stored in the mammalian liver (1mk)

(ii) Found in abundance in mammalian blood (1mk)

Identify the use of the following apparatus (3mks)

​(i) Bait trap

​(ii) Specimen bottle

​(iii) Pitfall trap

​a) State the functions of the following parts in a cell (2mks)

​(i) Nucleolus

​(ii) Smooth endoplasmic reticulum

​(b) Name an organelle that would be found in large numbers in cells of secretory glands (1mk)

Name two functions of sodium in human body (2mks)

​State the role of light in photosynthesis (1mk)

CELL PHYSIOLOGY

1. 1989 Q14 P1

NUTRITION IN PLANTS AND ANIMALS

​The diagram below shows chemical reactions I, and II which are controlled by enzymes respectively.

​Introduction to Biology

​Motor vehicles move, use energy and produce carbon dioxide and water. Similar characteristics occur in living organisms yet motor vehicles are not classified as living. List the other characteristics of living things that do NOT occur in motor vehicles.

K.C.S.E Biology Q & A - MODEL 2019PP2QN06

State one importance of irritability to living organisms.

Plasmodium vivax and Plasmodiuin ovale are transmitted by a mosquito. State with a reason whether the two organisms can interbreed.

Make a diagram of a simple, bibbed leaf with a serrated margin.

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A group of students set up an experiment to investigate a certain physiological process. The set up
was as shown in the diagram below.

(a) What physiological process was being investigated? (1mk)

(b) (i) State two major observation that was made after some time. (2mks)

(ii) Account for the above observation in b (i) above. (4mks)

(c) State the significance of the biological process involved in the experiment. (1mk)

List three characteristics that distinguish arthropods from organisms in kingdom Monera (3mks)

(a) Name the process shown by the equation above (1mk)

(b) List down a carbohydrate that is;-

(i) Bait trap

(ii) Specimen bottle

(iii) Pitfall trap

a) State the functions of the following parts in a cell (2mks)

(i) Nucleolus

(ii) Smooth endoplasmic reticulum

(b) Name an organelle that would be found in large numbers in cells of secretory glands (1mk)

State the role of light in photosynthesis (1mk)

The diagram below shows chemical reactions I, and II which are controlled by enzymes respectively.

Introduction to Biology

Motor vehicles move, use energy and produce carbon dioxide and water. Similar characteristics occur in living organisms yet motor vehicles are not classified as living. List the other characteristics of living things that do NOT occur in motor vehicles.