BECE Past Questions & Answers – 2010 (SCIENCE)
INTEGRATEDSCIENCE2
1¼hours
ESSAY
[100marks]
This paper is in two parts,I and II
Answer Question 1 in Part I and any other four questions in Part II.
Credit will be given for clarity of expression and orderly presentation of material
PART I
[40marks]
Answer all of Question1
1. (a) The diagram below is used to demonstrate an activity in the laboratory.
Study it carefully and use it to answer the questions that follow:
(i) What does the diagram represent?
(ii) Identify the components labelled D, E, K and Pin the diagram
(iii) State one function each of the parts labelled D, E, K and P.
(iv) Mention the energy transformation that occurs in E in the diagram when K is closed. [10 marks]
(b) In an experiment, red and blue litmus papers were dipped separately into three test tubes each containing one of the test substances listed in the table below.
Test substances |
Observations |
Conclusion |
|
Red litmus paper | Bluelitmus paper | ||
Lemon juice | |||
Calcium hydroxide solution | |||
Dilutehydrochloric
acid |
(i) Copy and complete the table by making the necessary observation and conclusion for
each substance.
(ii) Name two of the test substances that would react with each other to produce salt and water.
(iii) Write down a balanced chemical equation for the reaction in (ii) above.
[10 marks]
(c) The diagram below is an illustration of the human digestive system.Study it carefully and use it to answer the questions that follow:
(i) Name the parts labelled I, II, III and IV
(ii) State one function of each of the parts labelled V and VI
(iii) Name the part where the digestion of protein starts.
(iv) Identify the part where
(α) absorption of end-products of digestion takes place
(β) re-absorption of water takes place
(γ) egestion takes place
[10 marks]
(d) The diagram below is an illustration of a simple farm tool.
Study it carefully and use it to answer the questions that follow:
(i) Identify the tool
(ii) State three uses of the tool
(iii) Mention three ways of maintaining the tool
[10 marks]
PART II
[60marks]
Answer four questions only from this part.
2. (a)(i) What is neutralization reaction?
(ii) Write a balanced chemical equation for there action between each of the following pairs of substances:
(α) Sodium metal and dilute hydrochloric acid.
(β) Sodium hydroxide and dilute hydrochloric acid [6 marks]
(b) Explain weaning as used in animal production
(c) (i) What is milky way? [2 marks]
(ii) State one use of artificial satellites [3 marks]
(d) (i) What is a habitat?
(ii) Give two examples of a habitat. [4 marks]
3. (a) (i) Define pressure.
(ii) Explain why it is important to sharpen a knife before use
[4 marks]
(b) (i) State two differences between metal sand non-metals
(ii) What is an alloy?
(iii) Mention the components of each of the following alloys:
(α) steel
(β) brass
[6 marks]
(c) Mention three conditions suitable for rearing tilapia in a fishpond
[3 marks]
(d) Explain how the streamlined body of a bony fish enables it to live successfully in water
[2 marks]
4. (a) (i) What is a disease vector?
(ii) Mention two methods of controlling each of the following types of pests of farm
animals:
(α) ectoparasites
(β) endoparasites
[6 marks]
(b) (i) State two symptoms of nitrogen deficiency in a tomato plant.
(ii) Describe side dressing as a method of fertilizer application.
[5 marks]
(c) (i) Define power
(ii) State the S.I. unit of power.
[2 marks]
(d) Draw the electronic structure of sulphur
{Atomic number of sulphur = 16}
[2 marks]
5. (a) (i) What is respiration?
(ii) Name the types of respiration that occur in humans
[4 marks]
(b) List three ways of maintaining soil fertility [3 marks]
(c) (i) Write the systematic name of each of the following chemical compounds:
(α) FeS (β) SO2 (γ) CO2
(ii) Give one reason why copper, silver and gold are mostly used in making ornaments and jewellery.
[4 marks]
(d) (i) What is a fuse?
(ii) Explain why a fuse is used in an electrical circuit.
[4 marks]
6. (a) (i) What is the difference between unicellular organism and multicellular organism
(ii) State two reasons why vegetable crops are important to humans
[4 marks]
(b) (i) State two elements of climate
(ii) What is the difference between climate and weather?
[4 marks]
(c) Mention three advantages of staking in crop production [3 marks]
(d) Explain each of the following processes:
(i) corrosion;
(ii) sublimation
[4 marks]
CLICK TO VIEW ANSWERS TO PART 2
INTEGRATEDSCIENCE2
SOLUTIONS
ESSAY
1. (a) (i) An electrical circuit
(ii) The components:
D – Conductor wire
E – Cell or emf source
K – Switch or key
P – Resistor
(iii) Function of
D – Electric current flows through it
Or it conducts electricity
E – Provides the electromotive force (emf)
Or: provides the potential difference or voltage
Or: produces the electric current or electricity
Or: converts chemical energy to electrical energy
K – Opens or closes the circuit
Or: stops or starts the flow of current through the circuit
P – Opposes the flow of current through the circuit
Or: converts electrical energy to other forms
(iv) energy transformation that occurs in E in the diagram when K
Chemical energy→Electrical energy
(b) (i)
Test substances |
Observations |
Conclusion |
|
Red litmus paper | Bluelitmus paper | ||
Lemon juice | Remains red | Turns red | Acidicsubstance |
or: no colour change | or: Contains acid | ||
Calcium hydroxide solution |
Turns blue |
Remains blue or: no colour change |
Basic substance
or: Contains base |
Dilute hydrochloric
acid |
Remains red
or: no colour change |
Turns red |
Acidic substance
Contains acid |
(ii) Reactants to form salt and water:
Calcium hydroxide solution and dilute hydrochloric acid
(iii) Balanced chemical equation:
Ca(OH)2 + 2 HCl → CaCl2 + 2H2O
(c) (i) The parts:
I- salivarygland
II – oesophagus
III – stomach
IV- liver or: gullet
(ii)
Function of:
Part V- Stores bile Or: Concentrates bile
Part VI – Secretes juices containing enzymes into the small intestines
Or: secretes hormones such as insulin into the bloodstream
(iii) Digestion of protein starts at: Part III or The stomach
(iv) (α) absorption of end-products- Part VII -Small intestines
(β) re-absorption of water – Part VIII – Large intestines
( γ) egestion – Part X – Anus
(d) (i) The Tool – Secateurs or a pair of secateus
(ii) Uses of the tool
Trimming
Cutting
Pruning
(iii) Ways of maintaining the tool
Oiling or greasing metal parts
Washing and drying after use
Tightening bolts and nuts when loose
Sharpening cutting edges when blunt (any three)
2. (a) (i) Neutralization reaction
A chemical reaction between an acid and a base to produce salt and water
(ii) (α) Sodium metal and dilute hydrochloric acid.
2 Na + 2HCl → 2NaCl + H2
(β) Sodium hydroxide and dilute hydrochloric acid
NaOH+ HCl → NaCl + H2O
(b) Weaning
Starting to feed a young animal with food other than its mother’s milk
(c) (i) Milky way
(ii)the spiral galaxy to which Earth and its solar system belong
Use of artificial satellites
- Weather studies and forecasting
- Telecommunication
- Sending and receiving TV signals
- Taking photographs from space for various purposes
- Internet networking
- Global Positioning System (GPS)- a worldwide navigation system
[anyone of the above]
(d) (i) Habitat
The natural living place of a plant or animal
Or: The natural conditions and environment of an organism
(ii)Examples of habitat
Forest, desert, river or wetlands, tree,etc (any two)
3. (a) (i) Pressure
The force per unit area
Or: Pressure = force/area
(ii) When a knife is sharpened, the area at the cutting edge is reduced; hence greater pressure is attained at a given applied force. Therefore it cuts easily with less applied force.
(b) (i)
METALS | NON-METALS |
High meltingpoint | Low meltingpoint |
Shinysurface | Dull surface |
Malleable | Not malleable |
Ductile | Not ductile |
Good conductors ofheat | Bad conductors ofheat |
Good conductors ofelectricity | Bad conductors ofelectricity |
(ii) Alloy
A substance containing a metal and another metal or non-metal uniformly physically combined
Or: A homogeneous mixture of a metal and another metal or non-metal
(iii) (α) Steel – Iron and Carbon
(β) brass – Zinc and copper
(c) Conditions suitable for rearing tilapia in a fishpond
- Suitable salinity(salt concentration) of the pond
- Non-polluted water
- Favourable temperature of water
- Sufficient dissolved oxygen in the water
- Suitable pH of the water
(d) Importance of the streamlined body of a bony fish
Enables the fish to move smoothly or easily in the water
Or: it reduces the friction between the water molecules and the body of the fish.
4. (a) (i) Disease Vector
An organism that transmits disease-causing microorganisms from an infected person or
animal to another
(ii) Methods of control
(α) ectoparasites
- Use of pesticides
- Dipping
- Dusting
- Handpicking
- Use of foot bath
- Rotational grazing
(β) endoparasites
- Drenching
- Deworming
- Vaccination
- Regular change of feed and litter
(b) (i) Symptoms of nitrogen deficiency in a tomato plan
- Stunted growth
- Weak stem or branches
- Leaves turn yellowish
- Fruits are smaller and fewer than normal
(ii) Side dressing(fertilizer application)
Applying the fertilizer on / in the ground at the sides of the crop
(c) (i) Power
The time rate of doing work Or: The work done per unit time
Or: (work done) / (time taken)
(ii) S.I. unit of power = watt or W
(d) The electronic structure of sulphur (atomic no.16)
5. (a) (i) Respiration
The breakdown of food substances in an organism to release energy,carbon dioxide,
water
(ii)Types of respiration
External respiration and internal respiration
Or: Aerobic and anaerobic respiration
(b) Ways of maintaining soil fertility
- Crop rotation
- composting
- mulching
- Fertilizer application
- Bush fallowing
- Green manuring
- Planting of cover crops
- Mixed farming
(c) (i) Systematic names of:
(α) FeS – Iron (II) sulphide
(β) SO2 – Sulphur (IV)oxide
(γ) CO2 – Carbon(IV) oxide
(ii)Reasons
They are very malleable, ductile, have high lustre and less reactive.
(d)(i)Fuse
An electrical safety device containing a piece of a metal that melts if the current running
through it exceeds a particular level, there by breaking the circuit.
(ii)Why fuse is used in an electrical circuit
To protect the electrical circuit from damage caused by abnormal power surges or
increases
6. (a)
Unicellular organism | Multicellular organism |
organism is made up of only one cell | organism is made up of more than one cell |
(ii) Why vegetable crops are important to humans
- Good source of vitamins
- Good source of mineral salts
- Make food tasty
- They have high fibre content
(b) (i) Elements of climate
- Rain
- Temperature
- Humidity
- Sunshine
- Atmospheric pressure
- Cloud
- Wind
(ii) Differences
Climate | Weather |
atmospheric condition of a place over a
long period of time |
atmospheric condition of a place over a
short period of time |
(c) Advantages of staking in crop production
- Keeps fruits clean
- Enables easy weeding
- Enables easy harvesting
- Prevents early spoilage of fruits
- Keeps plant from falling during storms
- Keeps plant from falling under the weight of mature fruits
(d) (i) Corrosion explanation
A process by which a substance, especially a metal, is destroyed progressively by
chemical action. Example:the rusting of iron
(ii)Sublimation explanation
A process in which a substance is converted directly from a solid to a gas or from a gas to
a solid without passing through the liquid state
Example: the conversion of naphthalene ball(camphor) from solid to gas directly