Mastering KCSE Biology with Comprehensive Topical Questions and Answers
K.C.S.E Biology Q & A - MODEL 2001PP1QN18a
Describe the process of fertilization in a flowering plant
answers
pollen grains stick in the stigma surfaces; that surface of stigma producers a chemical substance; which stimulates the pollen grain to produce a pollen tube / germinate. The pollen tube/ germinate. The pollen tube grows down (into the tissues of style) from where it derives nutrients; the generative nucleaus divides to give rise to two male nuclei and the antipodal cells; when pollen tubes disintegrates and make nucleus fuses with the egg cell and forms the zygote. The other male nucleus fuss with the two polar nuclei to form a triploid nucleus. The process involves double fertilization.
0 Comments
K.C.S.E Biology Q & A - MODEL 2001PP1QN09
Name three types of chromosomal mutations
ANSWERS
K.C.S.E Biology Q & A - MODEL 2001PP1QN04
Name the parts of the flower that are responsible the production of gametes
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 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 2000PP1QN10
Explain how birds of prey are adapted to obtaining their food.
answers
K.C.S.E Biology Q & A - MODEL 2000PP1QN02
Give a reason why two species in ecosystems cannot occupy the same niche.
answers
K.C.S.E Biology Q & A - MODEL 1999PP1QN17
Explain how the various activities of man have caused pollution of air.
answers
K.C.S.E Biology Q & A - MODEL 1999PP1QN13b
Describe how population of grasshoppers in a given area can be estimated.
answers
​Use the capture and recapture methods; Catch the grasshoppers count and mark using permanent ink; record and release; and allow time 1 to 2 hours; recapture and count the marked and the unmarked; total population is equal to the number of marked and unmarked grasshoppers in the second sample multiplied by number marked grasshoppers in the first sample; divided by the number of grasshoppers marked in the second sample that were recaptured.
K.C.S.E Biology Q & A - MODEL 1999PP1QN13a
Distinguish between a community and population.
answers
K.C.S.E Biology Q & A - MODEL 1999PP1QN12
A student set up an experiment as shown in the diagram below..
a) i) What is being investigated in the experiment?
ii) On the diagram below indicate the expected results after three days.
​iii) Why was it necessary to have wet cotton wool in the containe?
b) What is the role of the following to a germinating seed/ i) Oxygen ii) Cotyledons.
answers
​.a) i) Region of elongation (rapid) growth in a root.
b) i) Oxygen
Oxidation of stored food; to provide energy (for germination) ii) Cotyledons Store food necessary for germination; protecting the plumule.
K.C.S.E Biology Q & A - MODEL 1999PP1QN08
State two disadvantages of self-pollination.
answers
State three ways by which plants compensate for lack of ability to move from one place to another.15/6/2020
K.C.S.E Biology Q & A - MODEL 1999PP1QN06
State three ways by which plants compensate for lack of ability to move from one place to another.
answers
K.C.S.E Biology Q & A - MODEL 1999PP1QN05
Suggest tree reasons why green plants are included in a fish aquararium.
answers
K.C.S.E Biology Q & A - MODEL 1999PP1QN03
Explain why sexual reproduction is important in organisms
answers
K.C.S.E Biology Q & A - MODEL 1998PP1QN15
The herbivorous mammalian species were introduced into an ecosystem at the same time and in equal numbers. The graph below represents their populations during the first seven years. Study the graph and answer the questions that follow..
(a) (i) Which species has a better competitive ability?
(ii) Give reason for your answer (b) Account for the shape of the curve species A between (i) One year and three years (ii) Three years and seven years (c) A natural predator for species A was introduced into the ecosystem. With a reason state how the population of each species would be affected.
answers
(a) (i) Species A;
(ii) The rate of multiplication/ growth in A is faster than of species B (b) (i) One year and three years 1-3 years shortage of resources more suitable environmental Conditions/ such as food space e.t.c resource were not limiting hence the population increased exponentially rapidly; acc correctly named resource e.g food space. (iii) Three years and seven years 3-7 years shortage of resources/ limiting/ birth rate equals death rate; hence the population had become stagnant/ constant; acc; Environmental resistance has set in rej. Incorrect resources e.g PT and T. (c) Species A would decrease (because of there is less competition with species A/ More resources available. K.C.S.E Biology Q & A - MODEL 1998PP1QN13
(a) List four differences between meiosis and mitosis
(b) Which sex chromosomes are found in human? Sperm cell? Ova?
K.C.S.E Biology Q & A - MODEL 1998PP1QN10
Give two reasons why primary productivity in an aquatic ecosystem decreases with depth.
ANSWERS
K.C.S.E Biology Q & A - MODEL 1998PP1QN08
A flower was found to have the following characteristics:
Inconspicuous petals Long feathery stigma Small, light pollen grains (a) What is the likely agent of pollination of the flower (b) What is the significance of the long feathery stigma in the flower?
ANSWERS
(a) wind
(b) To enable it trap pollen grains in the air; reject catch/ attach for trap
K.C.S.E Biology Q & A - MODEL 1997PP1QN19
Describe how the tapeworm is adapted to a parasitic mode of life
answers
Has hooks/suckers: for attachment to wall of intestines: long; to increase surface area for absorption of food: award increase in S.A for absorption once. Secretes enzymes/to neutralize digestive enzymes; (mucus inhibitor substance/anti enzymes) Hermaphroditic: to ensure reproductive/ self fertilization. Production of many eggs: to ensure survival
Segment for egg dispersal: More than one host; for transmission: e.g T solium – pig (Intermediate host) T. Saginata. Long to fit in the intestine/ increase surface area for ( flatten) Absorption of food; Anaerobic survive in the gut with low Oxygen
K.C.S.E Biology Q & A - MODEL 1997PP1QN19
What is parasitism?
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
|