INSTRUCTIONS TO CANDIDATES:
- Answer all the questions in this question paper
- Name the cell organelles that would be abundant in:
- White blood cells destroying pathogens (1mk)
- Palisade mesophyl cells (1mk)
- Skeletal muscle cells (1mk)
- The following graph represents a growth pattern observed in a group of animals
- Name the type of growth shown above (1mk)
- Name the phylum of animals whose members display the growth pattern named in (a) above (1mk)
- Identify the process which leads to increase in body size at the part marked S (1mk)
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- When observing a specimen through a light microscope, a student noted that the field of view was dark. Name 2 parts of the microscope that the student should adjust to make the field of view clear (2mks)
- A specimen was magnified 1000 times by a light microscope whose eye piece lens magnification is x10. Calculate magnification of objective lens (2mks)
- The flow diagram below represents a process of photosynthesis. Study diagram and answer the questions that follow
- Name the substances labeled (3mks)
- Write an equation to show the process illustrated above (1mk)
- Name the parts of the body of a mammal where each of the following types of joints are found (3mks)
- Fixed joints
- Gliding joint
- Huge joint
- The following is a diagrammatic representation of protein synthesis. Study and answer the questions that follow.
- Name process R (1mk)
- Where in the cell does R take place? (1mk)
- Name
- Product Q (1mk)
- Part X (1mk)
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- Name an element which is a present in proteins but is not in carbohydrates (1mk)
- State three functions of proteins in the human body (3mks)
- State the functions of the following cell structures during cell division (2mks)
- Centriole
- Centromere
- In a blood test, a few drops of anti- serum were added to two samples of blood. It was observed that agglutination occurred. What were the possible blood groups of the two blood samples (2mks)
- Name the division of the kingdom Plantae with the following spores producing bodies (2mks)
- Sori
- Sporangium
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- What structure in a mammal is represented by the following? (3mks)
- The rubber balloon
- The syringe case
- The plunger
- Describe what happens if the rubber plug is pulled in the direction shown by the arrow (1mk)
- What structure in a mammal is represented by the following? (3mks)
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- Define the term alleles (1mk)
- Explain why the body temperatures of a healthy human beings must rise up to 390C on a humid day (2mks)
- In an experiment, a piece of brain was removed from a rat. It was found that the rat had large fluctuation of body temperatures. Suggest the part of the brain that had been removed (1mk)
- Name the causative agent of the following diseases in humans (2mks)
- Ameobic dysentry
- Candidiasis
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- Define the term immunity (1mk)
- Distinguish between natural immunity and acquired immunity (2mks)
- Identify one immunizable disease in Kenya (1mk)
- The chart below shows a feeding relationship in a certain ecosystem
- Construct two food chains ending with a tertiary consumer in each case (2mks)
- Suggest two ways in which the ecosystem would be affected if there was a prolonged drought(2mks)
- State two functions of muscles found in the alimentary canal of mammals (2mks)
- Study the reaction below and answer the questions that follow
- What biological processes are represented by A and B (2mks)
- Identify the product Y (1mk)
- State the bond represented by X (1mk)
- State one use of each of the following plant excretory products
- Tannins (1mk)
- Colchines (1mk)
- Quinine (1mk)
- State two characteristics of aerenchyma tissue (2mks)
- The table below shows the percentage composition by volume of inhaled and exhaled air
Gas
Inhaled air %
Exhaled air %
Oxygen
21
16
Carbon(IV) oxide
0.04
4.0
Nitrogen
79
79
- By what percentage is carbon (IV) oxide concentration in inhaled air higher than exhaled air (2mks)
- Explain the differences in the composition of the gases between inhaled and exhaled air (3mks)
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- what is metamorphosis (1mk)
- What is the biological importance of the larval stage during metamorphosis (2mks)
- Explain how the following forces contributes to the movement of water up the xylem vessels (2mks)
- Cohesion
- Adhesion
- A solution of sugarcane was boiled with hydrochloric acid; sodium hydrogen carbonate was added to the solution which was then heated with benedict’s solution. An orange precipitate was formed
- Why was the solution boiled with hydrochloric acid? (1mk)
- To which class of carbohydrates does sugarcane belong? (1mk)
- State the form in which carbohydrates are stored in (2mks)
- Plants
- Animals
- How are lenticels adapted for gaseous exchange? (2mks)
- State the importance of the following process that takes place in the nephrons of human kidney
- Ultrafiltration (1mk)
- Selective reabsorption (1mk)
- The diagram below represents a section or portion of a certain nucleic acid With a reason, identify the types of nucleic acid whose portion is shown above
Identity 1mk
Reason 1mk
MARKING SCHEME
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- lysosomes
- chloroplast
- mitochondria( answer must be in plural)
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- intermittent growth curve
- Arthropoda( correct spelling)
- moulting
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- mirror
Diaphragm - total magnification =eyes piece lens magnification × objective lens magnification
1000 = 10 × y
1000/10= y
y= ×100
- mirror
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- A- Hydrogen ions
B- carbon iv oxide
C- carbohydrates ( accept glucose)
chlorophylL - 6CO2 + 6H2O → C6H12O6 + 6O2
sunlight
(accept word equation)
- A- Hydrogen ions
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- skull; pelvic bone
- ankle; wrist
- knee ; elbow
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- condensation
- ribosome
- Q- Polypeptide
X- peptide bond
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- nitrogen
- form the structure of animal fossils/ keratin in hair/ collagen in tendons and ligaments/ form myosis in muscles/ form enzymes and hormones/ form casein in milk/ source of enerhy during starvation
- centriole- produce spindle fibres
- centromere- holds chromatids together/ provide point of attachment to spindle fibres
- AB and B
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- sori- Pteridophyta
- sporangium- Bryophyta (for all spelling must be correct)
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- the rubbber balloon- lungs
- syringe case – thoracic vertebrae
- the plunger – diaphragm
- the balloon become inflated
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-
- Alleles- contrasting pair of genes
- Heat from the body is not lost to the surrounding through sweating because evaporation of sweat will below; as air is already saturated
- hypothalamus
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- Entamoeba Histolytica
- Caudidaalbicans
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- ability of the body to recognize foreign antigens and develop mechanisms of destroying them/ ability to resist infections
- natural immunity is inborn/ inherited/ passed from parents to off springs while acquired immunity is obtained in life( can only score 2 mks or zero)
- Tuberculosis/ Poliomyelitis/ Diptheria (mark the first to apper)
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- green plants →grass hopper→lizard →domestic cat
Green plants →mice→snakes→hawks
Green plants→mice→snakes→domestic cat - most plants will die/ dry ; some animals may starve to death
- green plants →grass hopper→lizard →domestic cat
- Acts as valves that close and/or open various parts of the canal/ controls food movements in alimentary canal by acting as valves
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- A- condensation
B- Hydrolysis - sucrose
- glycosidic
- A- condensation
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- tannins – tanning hides and skin
- colchicines – cause polyploidy
- quinunine- used as an anti-malaria drug
- thin cell wall; has large air spaces
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- 4.0 – 0.04/ 0.04 × 100 = 90%
- oxygen concentration reduces because it is used in respiration to produce energy ; carbon iv oxide increases greatly because it is produced during respiration as a by-product ; nitrogen gas concentration remained constant because it is neither used or produced by the body
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- change in body form during the life cycle of an organism
- in larvae stage there is a vigorous feeding; hence the insects obtain enough nutrients/ food
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- cohesion- water molecules cling to each other maintaining continuous column of water/ preventing the break of water column
- adhesion- water molecules cling to the sides of xylem walls
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- to breakdown the sucrose solution to simple sugars
- non- reducing sugar/ disaccharide
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- starch
- glycogen
- Cells are loosely arranged; to facilitate air circulation Cells have moist surfaces; to dissolve respiratory gases
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- ultrafiltration- to remove urea/ nitrogenous wastes/ toxic / harmful substances from the blood stream
- selective re- absorption- to return useful substances/ glucose and amino acids into the blood stream
- identity- ribonucleic acid
Reason- presence of organic base uracil
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