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2017 WASSCE (November) Integrated Science Paper Two – Essay
1. Question 1
a) Outline the path taken by inhaled air beginning from the nostrils to the alveolus.
b) i) What is the water cycle?
ii) State four processes involved in the water cycle.
c) List four factors that should be considered in selecting a site for large-scale vegetable
d) i) State three ways of protecting people from the effects of radioactivity.
ii) State two uses of nuclear energy.
a) i) The path taken by inhaled air is as follows:
Nasal cavity or Nostrils
Larynx or voice box –> Trachea or windpipe –> Bronchi or bronchus –> Bronchioles or bronchioles –> Alveolus
b) i) Meaning of water cycle
It is a set of natural processes that indicate the repeated use and release of water. OR
It describes how water evaporates from the surface of the earth into the atmosphere or cools or condenses into rain or snow in the clouds and falls again to the surface of the earth as rain or precipitation.
ii) Processes involved in the water cycle
• Evaporation (from water sources);
• Transpiration (from leaves of plants);
• Respiration (from humans and animals);
• Cooling or condensation of vapour (to form clouds or drops of water)
• Falling of rain or Precipitation or falling of snow;
• Collection into water sources;
• Used by plants or animals (to start the cycle again).
c) Factors to be considered in selecting a site for large-scale vegetable production
Type of soil or fertility of soil or pH of soil;
• Topography of the land;
• Nearness to source of water
• Nearness to market;
• Nearness to farmer’s settlement or residence;
• Easy accessibility of the site
• Availability of labour;
• Cost of preparing or acquiring the land;
• Climatic requirement of the crop;
• The biotic factors or prevalence of pest or diseases;
• Security or political stability;
d) i) Ways of protecting people from the effects of radioactivity
• Evacuation of people or resettle people or increasing the distance from radiation source
• Sheltering in rooms.
• Use of non-radioactive iodine to prevent uptake of radioactive iodine by thyroid gland
• Keeping radiation detector
• Educating people
• Wearing of protective clothing or shield or face mask or respirator
• Shortening the time of exposure
• Avoid drinking or eating contaminated water or food.
ii) Uses of nuclear energy
• Production of electricity
• Nuclear medicine or medical uses or human health
• Space missions
• Used in agriculture or preservation of food or sterilization of insects or pests or plant mutation or breeding.
• Used in small batteries in exploring space;
• Propulsion of space craft;
• Manufacture of atomic bomb;
• Hydrogen production or fertilizer production;
• In submarines;
• Sea water desalination;
2. a) i) Explain each of the following terms as used in maize production:
ii) State two diseases that affect maize.
b) i) Name the two biological systems which help to co-ordinate the body’s activities.
ii) Mention the two hormones produced by the pancreas,
iii) Name one disease condition associated with the failure of the pancreas to produce sufficient hormone.
c) Name the type of bond formed when there is a reaction between each of the following pairs of elements:
i) Carbon and oxygen;
ii) Hydrogen and sulphur;
iii) Copper and oxygen;
iv) Carbon and hydrogen;
d) i) Distinguish between permanent magnet and temporary magnet.
a) two uses of permanent magnets;
b) one use of temporary magnets;
Explanation of terms
?) Meaning of supplying
It is the replanting of seeds at the stands where seeds fail to germinate. OR
It is the replacement of ungerminated seed at a stand.
?) Meaning of thinning
It is the removal of excess seedlings from a stand.
ii) Diseases that affect maize are:
b) i) Names of biological systems which help to coordinate the body’s activities are:
The nervous system;
The hormonal or endocrine system.
ii) The hormones which are produced by the pancreas are:
iii) Disease condition associated with the failure of the pancreas to produce sufficient hormone is diabetes.
c) i) The type of bond between carbon and oxygen is covalent
ii) The type of bond between hydrogen and sulphur is covalent.
iii) The type of bond between copper and oxygen is ionic or electrovalent.
iv) The type of bond between carbon and hydrogen is covalent.
d) i) Distinction between permanent magnet and temporary magnet.
Permanent magnet Temporary magnet
They are made from hard magnet substances. – They are made from soft magnetic substances.
They maintain magnetism for a long period. – They possess magnetism only in the presence of a magnetic field.
ii) ? ) Uses of permanent magnet
To build electric motors or power windows in cars or wind shield wipers
In (refrigerator or fridge) doors
In electricity generators
In cathode ray tubes
To separate magnetic material from non-magnetic material
Magnetic screw drivers
In automobile or electric vehicles
In air conditioners or washing machines
Storage devices (hard drive or pen drive or floppy disk) of computer
In electric train or track
Television or computers or phones or loud speakers
Making of jewellery or bracelets or ear ring or necklaces or beads
?) Uses of temporary magnet
To separate materials of iron from scrap metals
3. a) i) Explain the term decombing as used in animal production
ii) State three reasons for castrating farm animals.
b) i) State two functions of the human ear.
ii) Name the structure in the ear that is responsible for each of the functions stated in (i).
c) i) Tabulate three differences between red blood cells and white blood cells.
ii) State the expected changed that will occur in the composition of the blood leaving a muscle of a person soon after a period of vigorous activity.
d) i) Differentiate between a saturated hydrocarbon and an unsaturated hydrocarbon.
ii) Give one example of an:
i) Explanation of the term decombing
It is the removal of combs of poultry or young birds to prevent restlessness infection caused by flies or for them to grow fat or avoid being pecked by others.
ii) Reasons for castrating farm animals
To remove odour
To fatten the animal or to facilitate growth
To prevent sexually transmitted diseases or sexual desire.
To make animal docile or to reduce aggression or sexual desire
To prevent in-breeding or indiscriminate mating.
Minimize stress on the animal, when done close to birth just after birth.
i) Functions of the human ear
ii) Names of the structures in the ear responsible for their functions
Hearing – cochlea or auditory nerve or pinna or eardrum or ear ossicle or auditory canal;
Balancing – semi-circular canals.
i) Differences between red blood cells and white blood cells
Red blood cells White blood cells
Red in colour or contains hemoglobin – Colourless or straw in colour or contains no haemoglobin
Have no nucleus – Have nucleus
Have a biconcave shape or cannot change shape – Have no specific shape or amoeboid or can change shape
Occur in large numbers – Less in numbers
Transport oxygen or carbon dioxide – Defend the body
Life span in 120 days or longer – Life span is shorter
Formed in liver and spleen in embryonic stage or formed in bone marrow after birth – Formed in bone marrow in both embryonic stage and adult stage
ii) Expected change in the composition of blood leaving a person’s muscle after vigorous activity are as follows:
There is increase in carbon dioxide
There is decrease in oxygen
There is decrease in glucose
i) Saturated hydrocarbons are hydrocarbons or compounds which have molecules containing only single covalent bounds unsaturated hydrocarbons or compounds with double or triple bonds between carbon atoms.
ii) ?) Example of alkane are:
Methane (or CH4), ethane (or C2H6), Propane (or C3H8), butane (or C4H10), pentane (or C5H12)
?) Examples of alkene are:
Ethane (or C2H4), propene (or C3H6), butane (or C4H8), pentene (or C5H10)
?) Examples of alkyne are:
ethyne (or C3H4), propyne (or C3H4), butyne (or C4H6), pentyne (or C5H8)
4. a) Describe briefly the process of seed germination.
b) Outline the procedure for nursing lettuce seeds.
c) i) Explain how p-n junction diode is formed.
ii) Describe how a p-n diode can be forward biased.
d) The following table gives information about some elements.
Study the table carefully and answer the questions that follow.
Element | Number of Protons | Number of Neutrons | Number of Electrons
A | 8 | 8 | 10
B | 17 | 18 | 18
C | 12 | 12 | 10
D | 11 | 12 | 10
E | 17 | 20 | 17
i) Which of the element(s) is/are positive ion(s)?
ii) Which of the element(s) is/are negative ion(s)?
iii) Which of the element(s) form(s) isotopes?
a) Description of the process of seed germination
• The seeds absorbs water and (swells up)
• The water activates the enzymes within the seed
• The enzymes break down food stored in the seed
• The products of the break down are transported to the growing regions
• The young or embryonic shoot or plumule and root or radicle emerges
b) Procedure for nursing lettuce seeds
• Level surface of bed using rake
• Make shallow drills with dibber
• Place seeds into the drills
• Cover drills with light amount of soil
• Cover bed with palm fronds
• Water the bed
c) i) Explanation of the formation of p-n junction diode
It is formed by doping one side of a semi- conductor with trivalent or acceptor impurity and the other side with a pentavalent or donor impurity
ii) Description of how a p-n junction diode can be forward biased
This can be done by connecting the p-type semiconductor of a diode to the positive terminal of a cell and the n-type to the negative terminal of the cell.
d) i) Elements which are positive ions are:
ii) Elements which are negative ions are:
iii) Elements which can form isotopes are:
5. a) i) List three causes of uneven heating of the earth’s surface.
ii) State two characteristics of westerlies.
b) i) State one function of each of the following mammalian teeth:
a) incisor; ?) canine; y) molar;
ii) State how the structure of each of the teeth in (i) is adapted for its function.
c) Name two diseases that affect:
i) Poultry ii) cattle
d) i) State two ways in which parallel wiring system in households is important.
ii) The power rating of an electric stove is 2 kW. Calculate the amount of energy it uses in 1 hour.
a) i) Causes of uneven heating of the earth’s surface
Curvature of the earth’s surface or the angle at which the sun’s rays strike the earth or the earth is a sphere with the equator heated more intensely than the poles,
Revolution of the earth around the sun.
Differences in land and sea temperatures
Rotation of the earth on its axis
The earth covered primarily with land and water which get heated and cool at different rates
ii) Characteristics of westerlies
They are hot air;
They are from the equator to the poles;
They have low density.
b) Functions of some mammalian teeth
?) Incisor is for cutting or biting or gnawing.
?) Canine is for tearing or piercing.
?) Molar is for grinding or
ii) Structural adaptation of some mammalian teeth
Incisor has sharp or chisel-shaped edge.
Canine has pointed edge or it is conical.
Molar has flat or cusped or ridged surface.
c) i) Diseases that affect poultry
Marek’s or fowl paralysis
Fowl pox or Avian flu or bird flu
Pullorum or bacillary white diarrhea
Chronic respiratory disease
ii) Diseases that affect cattle are:
Brucellosis or contagious abortion.
Babesiosis (red water or tick fever)
Mad-cow disease, etc.
d) i) Importance of parallel wiring in households
The same voltage is supplied to all lamps or all lamps receive their required currents or it ensures that lamps are bright.
When a lamp blows, it does not affect the functioning of other lamps or it is safe or reliable.
Lamps are controlled by individual switches or lamps can be turned on and off independently.
Simple to design.
It allows additional components or lamps.
ii) Calculation of amount of energy used
Energy = Power x Time = 2 kW x 1h
Energy = (2 x 1000) W x (1 x 60x 60) s
Energy = 7,200,000 J = 7.2 x 106 J
6. a) i) Explain the term management practices as used in animal husbandry.
ii) List three management practices undertaken in pig production.
b) i) Define momentum of a body,
ii) A body of weight 50 N moves with a velocity of 20 m/s. Determine the momentum of the body.
c) Outline the steps in the preparation of an ester in the laboratory.
d) i) State the mode of dispersal of each of the following fruits:
?) silk cotton;
?) Pride of Barbados.
ii) Mention one feature that adapts each of the fruits in (i) for dispersal.
i) Management practices are husbandry activities carried on animals to ensure proper growth or good health of the animals.
ii) Management practices undertaken in pig production are:
Clipping of needle teeth;
Disease and pest control;
Ensuring good sanitation control.
i) Definition of momentum of a body
It is the product of mass and velocity of a body
Determination of momentum of the body
Momentum = Mass x Velocity
W = mg
where w = weight and g = acceleration
Mass = Weight/(Acceleration due to gravity) = 50/10 = 5kg
Momentum = 5 x 20 = 100 kg ms-1
c) Steps in the preparation of ester in the laboratory
A small amount of alcohol is added to the same amount of alkanoic acid in a beaker or test tube.
A few drops of concentrated H2S04 are added to the mixture.
The mixture is warmed or heated gently.
An ester is formed or a sweet fruity smell indicates the presence of ester.
d) i) Mode of dispersal of some fruits
?) Pawpaw is dispersed by animal.
?) Silk, cotton are dispersed by wind.
?) Pride of Barbados is dispersed by explosive mechanism
ii) A feature that adapts the fruits mentioned in (ii) for dispersal
?) Pawpaw: Possession of fleshy mesocarp or it appears attractive.
?) Silk cotton: Presence of floss or it is light.
?) Pride of Barbados: Unequal drying of due to gravity