Mastering KCSE Biology with Comprehensive Topical Questions and Answers
K.C.S.E Biology Q & A - MODEL 2001PP1QN16
An experiment was carried out to investigate the nutritional value of two dry powder animals feeds X and Y over a period of six months. Twenty 5 month’s old castrated goats were use. The goats were divided into two equal groups A and B.
The animal’s in group A were fed on feed X throughout the experiment while those of group B were fed on feed Y. The feeds were supplemented with dry hay and water. The average body weight of each group of goats and the weight of the dry powder feeds were determined and recorded each month. The faeces produced by each group was dried and weighed and the average dry faecal output per month was also recorded. The results are as shown below.
(a) (i) What is the relationship between the amount of feed and the faecal output
(ii) Work out the average increase in weight for the animal’s in group A during The first four months The last two months (iii) Account for the average increase weight in goats in group A during the first four months The last two months (iv) Which of the two feeds is more nutritious? Give reason for your answer (b) State four uses of digested food in the bodies of animals (c) State four uses of water in the bodies of animals
answers
(a) (i) The more the feed the more the feacal output
The less the feed the less the faecal output (ii) The first four months
iii) Fast/ rapid/Active growth hence increase in weight
The last two months Slow growth, reached maturity iv) Feed X Give reason for your answer Group A gained (more) weight, on less food while group B lost weight on more food. b) growth, repair, protection, energy production c) a solvent, transport medium.. Hydrolyses of food, maintenance of temperature.
0 Comments
K.C.S.E Biology Q & A - MODEL 2001PP1QN15
The diagram below represents a set up to investigate the conditions necessary for seed germination.
The set up was left for 7 days
(a) What conditions were being investigated in the experiment? (b) State three reasons for soaking seeds in set ups A and B (c) What were the expected results after seven days?
answers
(a) water, temperature moisture (Acc. Warmth)
(b) Mobilize/ hydrolyze stored food/ active enzymes/ breaking of dormancy softening the testa / seed coat ( acc. As a solvent/ transport media.) (c) Setup A – those in set up A will germinate Setup B- those in set up B will not germinate Setup C- those in set C will not germinate K.C.S.E Biology Q & A - MODEL 2001PP1QN14
Tallness in pea plants is due to a dominant gene Two tall pea plants were crossed and their F1 generation were in the ratio of 3 tall: 1 short. Using letter T to represents the gene for tallness and t for shortness give the
(a) (i) genotype of the parents (ii) Gamete of the parents (iii) Genotype ratio of the F1 generation (b) What is meant by the term testcross in genetic studies?
answers
​(a) (i) Tt, Tt
(ii) Tt and Tt (iii) 1TT; 2Tt; 1tt/ 1 tall homozygous; 2 tall heterozygous 1 short homozygous 1:2:1 (b) Crossing a homozygous recessive organism with an organism which shows dominant characteristics. K.C.S.E Biology Q & A - MODEL 2001PP1QN13
The diagram below represents the nitrogen cycle
(a) State the process labeled
A D (b) Name the compound represented by B (c) Name the group of organisms labeled C (d) (i) name the group of plants which promote process A (ii) State the part of the plant where process A takes place (e) How would excess pesticides in the soil interfere with process A
answers
​(a) A – Nitrogen fixation
D – absorption (b) Nitrate/ nitrates/ NO2 (c) Denitrifying bacteria/ Denitrifiers (d) (i) Leguminous plants, (acc. Legume/ acc examples e.g beans peas) (ii) Roots nodules; rej root or nodules alone; acc; root (e) – Killing / reducing of composers - Killing/reduction of nitrogen fixing bacteria/ nitrogen fixing microorganisms - Destruction of leguminous plants K.C.S.E Biology Q & A - MODEL 2001PP1QN12
The graph below shows the effect of substance concentration of the rate of enzyme reaction.
(a) (i) Account for the shape of the graph between A and B
(ii) B and C (b) How can the rate of reaction be increased after point B? (c) State two other factors that effect the rate of reaction of enzyme reaction
answers
(a) (i) More active sites of enzymes available, for a large number of molecules of substrate; hence increase in the rate of reaction ( rapid of fast increase in the rate of reaction)
(ii) B and C Enzymes/ substrate are in equilibrium / All active sites are occupied; hence rate of reaction is constant. (b) Raising concentration of enzymes (c) PH, temperature, inhibitors/ cofactors K.C.S.E Biology Q & A - MODEL 2001PP1QN11
The diagram below represents a mammalian nephron
(a) Name the
(i) Structure labeled P (ii) Portion of the nephron between point X and Y (b) Name the process that takes place at point Q (c) Name one substance present at point R but absent at point S in a healthy mammal (d) The appearance of the substance you have mentioned in (c) above is a symptom of a certain disease caused by a hormone deficiency. Name the (i) Disease (ii) Hormone (e) State the structural modifications of nephrons found in the desert mammals
answers
(a) (i) Efferent arteriole/ vessels
(ii) Loop of henle (b) Ultra – filtration ( acc. Pressure filtration) rej. Filtration (c) Glucose ( acc. Blood sugar) (d) (i) Disease – diabetes mellitus ( acc. Sugar diabetes) (ii) Hormone – insulin (e) Small Bowman’s Capsule/ Groleruli`; Rej few Bowman’s capsule Loop of Henle
K.C.S.E Biology Q & A - MODEL 2001PP1QN10
Name three sites where gaseous exchange takes place in terrestrial plants.
ANSWERS
K.C.S.E Biology Q & A - MODEL 2001PP1QN09
Name three types of chromosomal mutations
ANSWERS
K.C.S.E Biology Q & A - MODEL 2001PP1QN08b
Name the blood vessel that transports blood from:
(i) Small intestines to the liver (ii) Lungs to the heart
ANSWERS
(i) Hepatic portal vein
(ii) Pulmonary vein
K.C.S.E Biology Q & A - MODEL 2001PP1QN08a
The type of circulatory system found in members of the class insecta is
ANSWERS
K.C.S.E Biology Q & A - MODEL 2001PP1QN07
Name the organelle in which protein synthesis takes place
ANSWERS
K.C.S.E Biology Q & A - MODEL 2001PP1QN06
Adult elephants flap their ears twice as much as their calves in order to cool their bodies when it is hot. Explain.
ANSWERS
K.C.S.E Biology Q & A - MODEL 2001PP1QN05
State two functions of muscles found in the alimentary canal of mammals.
ANSWERS
K.C.S.E Biology Q & A - MODEL 2001PP1QN04
Name the parts of the flower that are responsible the production of gametes
ANSWERS
A person whose blood groups is AB requires a blood transfusion. Name the blood groups of the donors.16/6/2020
K.C.S.E Biology Q & A - MODEL 2001PP1QN03
A person whose blood groups is AB requires a blood transfusion. Name the blood groups of the donors.
ANSWERS
K.C.S.E Biology Q & A - MODEL 2001PP1QN02
Why are green plants referred to as primary producers in an ecosystem?
ANSWERS
K.C.S.E Biology Q & A - MODEL 2001PP1QN01
Other than having many features in common, state the other characteristics of a species
ANSWERS
K.C.S.E Biology Q & A - MODEL 2000PP1QN19
How are leaves of mesophytes suited to their functions
answers
​Broad/ wide/ flat lamina provides large surface area for absorption of (O) and sunlight, thin to ensure short distance of CO2 reach photosynthesis/ palisade cells; presence of stomata guard cells for efficient diffusion of O2 gaseous exchange / H2O vapour transpiration/ CO2 into the leaf transparent cuticle epidermal cells; for light penetration into palisade cell which contains chloroplast next to upper epidermis; these receives maximum light for photosynthesis. Chloroplasts have chlorophyll, which traps light energy.
Leaves have vein, xylem and phloem to transport products of photosynthesis to other part of the plant. Air spaces on spongy mesopyll, easily circulates gases/ CO2 diffuse into palisade cells. Mosaic arrangements of leaves; enable leaves to trap sunlight.
K.C.S.E Biology Q & A - MODEL 2000PP1QN18
Describe the role of hormones in the human menstrual cycle
answers
​Inferior lobe of pituitary gland secretes F.S.H which causes grafian follicle develops in the ovary. It also stimulates ovary tissue/ ovary/ follicle walls secret estrogen which repairs, heals uterine wall, oestrogen stimulates inferior lobe of pituitary gland produce L.H. for ovulation. It also causes grafian follicle change into corpus interim L.H stimulates corpus luteum secret progesterone which causes proliferation of the uterine walls; in preparation of implantation; oestrogen/ progesterone inhibits the production of F.S.H ( by anterior lobe of pituitary) thus no more follicle develop; and oestrogen production reduces; 14 days later progesterone level rises inhibits production of L.H from anterior lobe of pituitary gland produce L.H for ovulation. It also causes grafian follicle change into corpus interim L.M stimulates corpus luteum secret progesterone which causes proliferation of the uterine walls in preparation of implantation; oestrogen/ progesterone inhibits the production of F.S.H ( by anterior lobe of pituitary) thus no more follicle develop; and oestrogen production reduces; 14 days later progesterone level rises inhibits production of L.H from anterior lobe of pituitary gland/ The corpus luteum stops secreting progesterone, and menstruation occur when the level of progesterone drops; ( anterior lobe of pituitary starts secreting F.S.H again.
K.C.S.E Biology Q & A - MODEL 2000PP1QN17
The numbers of different types of animals supported by a square kilometer in two terrestrial ecosystems are shown in the table below
(a) (i) Which domestic animal is better adapted to both ecosystems?
(ii) Give a reason why the animal named in (a) (i) above is better adapted to the two ecosystems. (b) Why are cattle and sheep fewer in the bush land than in the savannah? (c) (i) Name suitable methods that were used to estimate the population of: Domestic animals Wild animals (ii) Give a reason why the method named for wild animals in (c) (i) above is suitable (d) state three methods which could be used to determine the diet of wild animals in an ecosystem (e) Name four biotic factors that could have regulated the animal population in both ecosystems (f) State four human activities that affect population of animals in game parks (g) What is the importance of national park to a nation?
answers
​(a) (i) Goat
(ii) It is a grazer and a browser (b) Insufficient grass in bush/ aren’t adapted to eating twigs/ not browsers/ are grazers (c) (i) Domestic animals - total counts Wild animals – total counts; aerial counts/ quadrat/ Belt transect/ capture/ recapture (ii) Analyzing gut counts, studying dentition/ breaks/ claws/ parts (d) Observation Examine droppings Dissecting a sample of animals/ study structure/ nature of digestive System/ size of caecum/ length of intestine/ chamber (e) Irrigation Competition; diseases Predation; human activity/ man accept any correct Parasitism (f) Poaching, cropping/ culling/ licensed spot hunting (g) Pollution; translocation Burning trees, charcoal- deforestation
K.C.S.E Biology Q & A - MODEL 2000PP1QN16b
State three advantages of asexual reproduction
answers
K.C.S.E Biology Q & A - MODEL 2000PP1QN16a
What is the significance of sexual reproduction?
answers
K.C.S.E Biology Q & A - MODEL 2000PP1QN15
The concentration of the lactic acid in blood during and after an exercise was determined. The results are shown in the graph below
(a) (i) By how much did the lactic acid increase at the end of 13 minutes?
(ii) After how many minutes was the lactic acid concentration 71mg/100cm3? (iii) What would be the concentration of lactic acid at the 60th minute? (b) Give a reason for the high rate of production of lactic acid during the Exercise (c) Give a reason for the decrease in the concentration of lactic acid after the exercise
answers
​(a) (i) 78/78 mg/ 100cm3
(ii) 8.5th and 29.5th / 8min 30 sec and 29 min 30 sec (iii) 47 mg/100cc; Acc. 47 (b) The demand for oxygen is more than the supply leading to anaerobic respiration. Acc. Lactic acid converted to glucose/Glycogen (c) Lactic acid is oxidized ( to form CO2 and H2O) Acc. Lactic acid is converted to glucose/ glycogen K.C.S.E Biology Q & A - MODEL 2000PP1QN14
(a) Name the crop infested by phytophthora infestant and the disease it causes Crop / Disease
(b) State four control measures against the disease
answers
​(a) Crop
Potatoes / tomato Disease Tomato/potato bright/ Acc. Tomato rot (b) Use of fungicides Eradication of infected crop/ uprooting/ burning of infected plants Use biological control Use of disease resistant varieties Crop rotating K.C.S.E Biology Q & A - MODEL 2000PP1QN13
The temperature of a person was taken before, during and after taking a cold bath. The results are shown in the graph below
(a) Explain why the temperature fell during bath
(b) What changes occurred in the skin that enabled the body temperature to return to normal?
answers
​(a) Heat loss by conduction/ convection from the blood vessels
The body skin to the cold water, the cooler blood leaving skin enters general circulation cooling the whole body. (b) Vasoconstriction; thus less blood flowing to the skin reducing heat loss. Sweating eases heat produced through metabolism Accept shivering producing heat |
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
|