Mastering KCSE Biology with Comprehensive Topical Questions and Answers
K.C.S.E Biology Q & A - MODEL 2006PP1QN15
Explain continental drift as an evidence of evolution.
answers
​Current continents existed as one large land mass/ Pingea/ Laureshia Guondaland; the present continent drifted leading to isolation of organisms; organism in each continent evolved along different lines hence emergence of new species,
0 Comments
K.C.S.E Biology Q & A - MODEL 2006PP1QN14
Why is oxygen necessary in the germination of seeds?
answer
Name two modern methods of food preservation and for each state the biologic principle behind it.18/6/2020
K.C.S.E Biology Q & A - MODEL 2005PP1QN16
Name two modern methods of food preservation and for each state the biologic principle behind it.
answers
b) Refrigeration
It inactivates disease causing organisms/micro-organisms. Irridation –The radiation kills/destroys the micro-organism. Pasteurization (for milk only) Canning-Kills the micro – organisms.
K.C.S.E Biology Q & A - MODEL 2005PP1QN16
Name two organisms that cause food spoilage
answers
​a) - Fungus
-Bacteria K.C.S.E Biology Q & A - MODEL 2005PP1QN15
a) What is meant by the terms
(i) Epigymous flower (ii) Staminate flower? b) How are the male parts of wild pollinated flowers adapted to their function?
answers
a)i) A flower whose ovary is situated below the other floral parts.
ii) A flower with only the male reproductive parts parts (male flower) b) Larger anthers. Anther loosely attached Flexible filament Small, smooth and light pollen grains K.C.S.E Biology Q & A - MODEL 2005PP1QN14
A set up that was used to investigate certain process in plants is shown in the diagram below.
​a) What process was being investigated?
b) (i) State two precautions that should be taken when setting up the experiment. (ii) Give a reason for each precaution stated in b(i) above. c) State three environmental factors that influence the process Under investigation.
answers
a) Transpiration
b)i) The leafy shoot should be from herbaceous plant Cut off the last few centimeters of the stalk under water All the air in the capillary tubule should be expelled Jelly should be applied around the stem around the rubber bung. The end of the capillary fusing should rest in beaker of water. ii) Avoid air bubbles. For continuity of the flow of water Jelly should not touch the xylem vessels because it might block they xylem. To avoid introduction of air bubbles in the xylem. For continuity of water uptake. c) Temperature Humidity Wind Atmospheric pressure Light intensity Availability of water K.C.S.E Biology Q & A - MODEL 2005PP1QN13
The diagram below shows a section through the mammalian skin.
a) Name the parts labeled E, F and G.
E ………………………………………… F ………………………………………… G ………………………………………… b) State two functions in each case of substance secreted by the structures labeled. (i) H ………………………………… (ii) I ………………………………….
answers
​a) E – Malpighian layer
F – Nerve cell G – Erector pili muscle b)i) H – Excretion of waste products of metabolism from the body e.g. excess. Water, mineral salts traces of urea, lactic acid etc. Temperature regulation in the body brings a cooling effect through Loss of excess heat by evaporation of water. Keeps the hair and epidermis flexible and water proof Contains antiseptic substances for protection against bacteria. K.C.S.E Biology Q & A - MODEL 2005PP1QN12
In a garden with plants of same species, 705 plants had red flowers while 224 had white flowers.
a) Work out the ratio of red to white flowered plants b) (i) Using letter R to represent the dominant gene, work out a cross between F1 offspring and a white flowered plant. (ii) What is the genotypic ratio from the cross in b(i) above? c) What is meant by the term allele? K.C.S.E Biology Q & A - MODEL 2004PP1QN17
During germination and growth of a cereal, the dry weight of endosperm, the embryo and total dry weight were determined at two – day intervals. The results are shown in the table below.
a) Using the same axes, draw graphs of dry weigh of endosperm, embryo and the total dry weight against time
b) What is the total dry weight on day 5? c) Account for: i) Decrease in dry weight of endosperm from day 0 to 10 ii) Increase in dry weight of embryo from day 0 day 10 iii) Decrease in total dry weight from day 0 to day 8 iv) Increase in total dry weight after day 8 d)Dormancy. i) Within a seed ii) Outside the seed e) Give two characteristics of meristematic cells
answers
​(b) 38.5 (mg); Acc. + 0.5 ( i.e. 38 – 39)
(c) (i) Hydrolysis of starch into simple sugars; which are translocated to the embryo; Respiration/ to give energy/ heat/ gases Acc. Simple sugar oxidized (ii) New materials are synthesized from protein); bringing about growth of embryo; acc new cells/ protoplasm synthesized (iii) The rate of respiration is faster than that of synthesis of materials for growth (iv) First leaf (carried out photosynthesis) leading to growth (d) (i) Presence of absiscic acid/ germination inhibitors; Embryo not fully developed Absence of hormones/ enzymes that stimulate germination Impermeable seed coat; rej hard seed coat Acc. Inactive enzymes/ hormones/ absence of gibberellins/ cytokinins. (ii) – Unsuitable / unfavourable temperature - absence of light - lack of water - lack of oxygen (c) Dense cytoplasm - Thin cell wall - Absence of vacuoles ( cell sap)
K.C.S.E Biology Q & A - MODEL 2004PP1QN16
Outliner three roles of active transport in the human body
answers
K.C.S.E Biology Q & A - MODEL 2004PP1QN16
how do the following factors affect the rate of diffusion?
i) Diffusion gradient ii) Surface area volume ratio iii) Temperature
answers
(i) The higher diffusion gradient between ( two points) the rate of diffusion; acc converse.
(ii) The higher the surface area:: Volume ratio, the faster is the rate of diffusion ; acc converse (iii) Increasing temperature increases the rate of diffusion; acc converse.
K.C.S.E Biology Q & A - MODEL 2004PP1QN16
What is diffusion
answers
K.C.S.E Biology Q & A - MODEL 2004PP1QN15
a) Give the differences between the following structures in wind and insect pollinated flowers.
i) Anther ii) Pollen grains iii) Stigma b) What is the importance of cross pollination? c) Explain how a seed is formed after an ovule is fertilized
answers
​(i) anther Insect Wind
Small short anther firmly Large/ long anthers/ loosely attached to Attached to elements filaments (ii) Large heavy/ spiky small/ light/ smooth (iii) Small/ sticky Long feathery (b) Source of variation/ hybrid acc. Production of hybrid K.C.S.E Biology Q & A - MODEL 2004PP1QN14
What is meant by the following terms? Give an example in each case.
i) Homologous structures ii) Example iii) Vestigial structures Example
answers
​(i) Have a common ( embryonic) origin modified to perform different functions; vertebrae for limb/ pentadactyl limb
Example Vertebrate fore limb/ pretadactyl limb; acc beaks of birds ( fee of birds/ mouthparts in insects. (ii) Have different (embryonic) origins ( but have evolved) to perform similar functions. (iii) Are greatly reduced in size and therefore caused to function Acc. Third digit of wing of bird Halteres in flies Presence of hind limb ( buds) in python Human ear muscles Example Human appendix / kiwi ( flightless bird) with reduced wings/ vestigial wings in flies human hair/ presence of hind limbs in python; reduced pelvic girdle of whale.
K.C.S.E Biology Q & A - MODEL 2004PP1QN14
What is the difference between Darwinian and Lamarckian theories of evolution?
answers
Lamarckian
Inheritance of acquired characteristics/ Environment induces production of inheritable character which is then inherited.while Darwinian Inheritance of genetically acquired characteristics/ character happens to appear spontaneously which then gives advantage to organisms therefore better- adaptable characters are then inherited by natural selection. K.C.S.E Biology Q & A - MODEL 2004PP1QN13
The diagram below shows a vertical section through a mammalian heart.
​a) Name the parts labeled A,B,E and F
b) Use arrows to show the direction in which blood flows in the heart. c) Give a reason why the wall of chamber C is thicker than chamber D
answers
(a) A Pulmonary vein
B Left atrium I auricle E Tricuspid valve F Pulmonary artery
​(b) The left ventricle ‘C’ pumps blood a longer distance to all parts of the body; while the right ventricle ‘D’ pumps blood to a shorter distance/ to the lungs; therefore the left ventricle has thicker walls to generate exert more pressure.
K.C.S.E Biology Q & A - MODEL 2004PP1QN12
Across between a red flowered plant and white flowered produced plants with pink flowers.
Using letter R to represent the gene for red colour , and W for white colour a) What were the parental genotypes b) Workout a cross between F1 plants c) Give the i) Phenotypic ratio of F2 plants ii) Genotypic ratio of F2 plants d) Name a characteristic in humans, which is controlled through a mammalian heart?
answers
(a) RR WW
(b) Parental genotypes R W Gametes R W X WW R W Fertilization Offsprings RR RW RW WW (c) (i) Phenotypic ration Red Pink White 1 2 1 (ii) 1RR : 2RW; 1WW (d) (ABO) blood grouping; blood groups;
K.C.S.E Biology Q & A - MODEL 2003PP1QN16
K.C.S.E Biology Q & A - MODEL 2003PP1QN16
a) What is meant by:
i) Autecology ii) Synecology? b) The number and distribution of stomata on three different leaves are shown in the table below:
Suggest the possible habitat of the plants from which the leaves were obtained
Leaf Habitat A B C (c) State the modifications found in the stomata of leaf C.
answers
a) i) study of a single species within a community / ecosystem /habitat / environment.
ii) Synecology? Study of natural communities within an ecosystem b) Leaf Habitat A aquatic / fresh water B Forest; Terrestrial C Arid / semi arid; desert. c) Sunken Hairy Reserved rhythm Small stomatal pore
K.C.S.E Biology Q & A - MODEL 2003PP1QN14
Explain the role of antidiuretic hormone when there is excess water in the human body.
answers
K.C.S.E Biology Q & A - MODEL 2003PP1QN15
A response exhibited by a certain plant tendril is illustrated below.
​a) i) Name the type of response
ii) Explain how the response named in (a)(i) above occurs b) What is the importance of tactic responses to microscopic plants? c) State four applications of plant hormones in agriculture.
answers
a) i) Thigmotropism / haptotropism
ii) Contact with support; causes migration of auxine to enter the side; causing faster growth on the side away from centre of surface (causing tendrils curl around support.) b) Escape injurious stimuli / seek favorable habitats; move towards light / stimuli. c) Induce foot growth in stem cutting
K.C.S.E Biology Q & A - MODEL 2003PP1QN14
Explain how marine fish regulate their osmotic pressure.
answers
K.C.S.E Biology Q & A - MODEL 2003PP1QN13
The diagram below shows gaseous exchange in tissues.
a) Name the gas that diffuses:
i) To the body cells ii) From the body cells b) Which compound dissociates to release the gas named in (a) (i) above? c) i) what is tissue fluid? ii) What is the importance of tissue fluid? d) Name the blood vessel with the highest concentration of: i) Glucose ii) Carbon dioxide
answers
​a) i) Oxygen
ii) Carbon dioxide b) Oxyhaemoglobin c) i) The blood plasma except blood cells and proteins; that has filtered out of the capillaries. ii) It is a medium of exchange of substances/ materials between capillaries and body cells; supply nutrients to cells / supply oxygen to cells / remove waste products from cells. d) i) Hepatic portal vein ii) Pulmonary artery K.C.S.E Biology Q & A - MODEL 2003PP1QN12c
In Drosophila Melanogaster, the inheritance of eye colour is sex – linked. The gene of red eye is dominant. A cross was made between a homozygous red – eyed female and a white – eyed male. Work out the phenotypic ration of F1 generation. (Use R to represent the gene for red eyes).
K.C.S.E Biology Q & A - MODEL 2003PP1QN12b
Name two sex – linked traits in humans.
answers
K.C.S.E Biology Q & A - MODEL 2003PP1QN12
What is meant by the term sex – linkage?
answers
|
Archives
December 2024
Categories
All
TOPICSFORM 1
Form 2
Form 3
Form 4
|
We Would Love to Have You Visit Soon! |
Hours24 HR Service
|
Telephone0728 450425
|
|
8-4-4 materialsLevels
Subjects
|
cbc materialsE.C.D.E
Lower Primary
Upper Primary
Lower Secondary
Upper Secondary
|
teacher support
Other Blogs
|