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A piece of sealing wax, weight 3N in air and 0.22N when immersed in water, calculate the density of the wax.
Date posted:
May 25, 2019
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A glass capillary contains enclosed air by a thread of mercury 15cm long when the tube is horizontal, the length of the enclosed air column is 24cm as shown.
(i) What is the length of the enclosed air column when the tube is vertical with the open end uppermost if the atmospheric pressure is 750mmHg?
(ii) What is the length of the enclosed air column when the tube is vertical with the closed end upper most if the atmospheric pressure is 750mmHg.
(iii) Explain why the mercury does not run out when the tube is vertical with the closed end uppermost.
Date posted:
May 25, 2019
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The figure below shows an inclined plane, a trolley of mass 60kg being pulled up the slope by a force of 200N parallel to the slope. The trolley is moved from X to Y.
Determine the
(i) Work output of the system.
(ii) Work input of the system.
(iii) The frictional force between the wheels of the trolley and the inclined plane.
(iv) The efficiency of the system.
(v) The velocity ratio of the system.
Date posted:
May 25, 2019
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When the flask is placed in iced water the level on water rose and then fell. Explain this observation.
Date posted:
May 25, 2019
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An aircraft 300m from the ground traveling horizontally at 400m/s releases a parcel. Calculate the horizontal distance covered by the parcel from the point of release.(Ignore air resistance).
Date posted:
May 25, 2019
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Sketch a velocity – time graph for a body initially moving at a velocity u before a force F is applied to it for 5 seconds and there after the force F is withdrawn.
Date posted:
May 25, 2019
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A bus that carries goods in the under seats carrier is more stable than one that carries goods in the carrier at the top. Explain why this is so.
Date posted:
May 25, 2019
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The figure below shows a wire wound on a metal rod. The windings just touch each other. If the total number of complete loops was found to be 25 and the distance covered by the windings on the rod is 0.6cm, find the radius of the wire giving your answer in standard form.
Date posted:
May 25, 2019
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A sharp point of a pin is held over a positively charged electroscope. State and explain the observation made on the electroscope.
Date posted:
May 25, 2019
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Give the contrasting difference in chemical properties of chlorine and hydrogen?
Date posted:
May 24, 2019
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Name the organelles that would be most likely found in large numbers in cells that perform the functions below.
a) A cell in the ileum that actively takes in glucose
b) A cell in the liver that breaks down foreign bodies
Date posted:
May 24, 2019
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An experiment was carried out to investigate haemolysis of human red blood cells. The red blood cells were placed in different concentration of sodium chloride solution. The percentage of haemolysed cells was determined. The results were as shown in the table below.
a) i) On the grid provided, plot a graph of haemolysed red blood cells against salt concentration.
ii)At what concentration of salt solution was the proportion of haemolysed cell equal to non-haemolysed cells?
iii) State the percentage of cells haemolysed at salt concentration of 0.45%.
b) Account for the results obtained at:
i) 0.33 percent salt concentration.
ii) 0.48 per cent salt concentration.
c) What would happen to the red blood cells if they were placed in 0.50 percent salt solution?
d) Explain what would happen to onion epidermal cells if they were placed in distilled water.
Date posted:
May 24, 2019
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The diagram below represents a food web in a certain ecosystem.
a) Name the trophic level occupied by each of the following:
i) Caterpillar .
ii) Small insects .
b) From the food web, construct two food chains which end with lizards as tertiary consumer.
c) i) Which organisms have the least biomass in this ecosystem?
ii) Explain the answer in c(i) above.
Date posted:
May 24, 2019
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State the structural modification of nephron in the desert mammals.
Date posted:
May 24, 2019
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An experiment was carried out to find out the concentrations of ions in the cell sap of an aquatic plant and that of the water in the pond in which they grew.
a) i) Name the process by which the aquatic plant absorbs ions from the pond water.
ii) Outline four roles of the process you have named in (a) (i) above in a mammalian body.
b) How can the rate of uptake of ions by aquatic plants be increased.
c) Name the part of the cell that allows passage of ions in and out of the cell.
Date posted:
May 24, 2019
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A volume of 15cm3 of ethane gas was exploded with 50cm3 of oxygen. If both volumes were measured at the same temperature and pressure, calculate the volume of resulting gaseous mixture.
Date posted:
May 24, 2019
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When pure breeding red flowered plants were crossed with pure breeding white flowered plant, the offspring were all pink
flowered.
a) Using letter R to represent the gene for red coloured flower plants and W for the gene for the white flowered plants.
Workout the genotypic ratio of F2 generation.
b) State the phenotypic ratio of F2 generation.
c) i) What is the name given to a condition when two alleles in heterozygon state contribute equally to the phenotype of an
organizations.
ii) Give an example of a trait in human beings where the above condition in c(i) above express itself.
Date posted:
May 24, 2019
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How is a sugarcane flower adapted to wind pollination?
Date posted:
May 24, 2019
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Differentiate between photosynthesis and respiration.
Date posted:
May 24, 2019
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In an experiment, a black mouse was mated with a brown mouse. All the offsprings in F1 generated were black. The offspring grew and were all allowed to mate with one another. The total number of F2 generation offspring were 96.
(a) Using letter B to denote the gene for black colour, work out the genotype of the F1 generation.(Use a punnet square)
(b) State the following for the F2 generation.
(i) Genotypic ratio.
(ii) Phenotypic ratio
(iii) The total number of brown mice.
Date posted:
May 24, 2019
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The following diagram is a longitudinal section of the root apex.
Identify the parts labeled A, B and C.
Date posted:
May 24, 2019
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The graph below represents the growth in a certain phylum.
(a) Name the type of growth pattern shown on the graph.
(b) Identify the process represented by X.
(c) Name the hormone responsible for the process in (b) above.
Date posted:
May 24, 2019
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What characteristics do mammalian lungs and the gills of bony fish have in common that enables them to exchange gases efficiently?
Date posted:
May 24, 2019
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State two adaptation of herbivorous which enable them to digest cellulose?
Date posted:
May 24, 2019
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An element Q has a relative atomic mass of 88. When a current of 0.5A was passed through the fused chloride of Q for 32 minutes and 10 seconds, 0.44g of Q were deposited at cathode. Determine the charge on the ion of Q. (1 Faraday = 9650
Date posted:
May 24, 2019
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With a reason, name the organelles that would be found in large numbers in cell of secretory glands.
Date posted:
May 24, 2019
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The electronic structures for elements represented by letters A, B, C and D are
A - 2.8.6 B - 2.8.2 C - 2.8.1 D - 2.8.8
a) Select the element which forms :
i) a double charged cation
ii) a soluble carbonate
b) Which element has the shortest atomic radius ?
Date posted:
May 24, 2019
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Imaginative Composition
(a) Write an interesting composition ending with … I trudged wearily and regretted why I left home without
permission.
Or
(b) Write a story to illustrate the saying “Opportunity seldom knocks twice
Date posted:
May 24, 2019
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State three sites of gaseous exchange in mesophytes.
Date posted:
May 24, 2019
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The diagram below shows an experiment on germination peas.
a) (i) What changes are observable at the end of the experiment?
(ii) Give the reason the observation in a(i) above.
(b) If water had been used instead of caustic potash in the experiments, what would be observed?
Date posted:
May 24, 2019