PART II
[60 marks]
Answer four (4) questions from this section.
2. (a) (i) Which organ controls blood circulation in mammals?
(ii) State two (2) functions
of this organ.
(iii) Name two (2) diseases of the organ named in (a)(i) above.
(b) (i) Name two (2) devices which can convert electrical energy into heat
(ii) What is the working resistance of a bulb that takes a current of 0.25
when it is connected to the 220V mains supply?
(c) (i) What is the role of acids in biological systems such as digestion?
(ii) Kofi wants to measure the acidity of a substance, what instrument w
needs and how does the instrument relate to acid strength?
(d) How do human activities like deforestation and intensive farming impa
soil health?
3. (a) (i) How do nitrogen-fixing bacteria contribute to soil fertility?
(ii) List two (2) examples of nitrogen fixing bacteria.
(b) (i) What are the basic components of an electrical circuit?
(ii) How do series and parallel circuit differ in terms of resistance and
current flow?
(c) (i) Compounds are chemically combined of two or more elements.
Ham State two (2) characteristics of compound.
(ii) Name two (2) examples of compound used in
(a) home
(B) pharmaceutical
(d) (i) Mosquito undergoes four stages in its life cycle. State how long doe
each stage typically last.
(ii) Environmental factors affect the mosquito life cycle, name two (2)
such environmental
factors.
4. (a) (i) What is the relationship between force, mass and acceleration accor
to Newton's second law?
(ii) A car accelerates from 0 to 60km/h in 10 seconds with mass 200kg.
What is the
average force applied?
(b) (i) What are the stages of water cycle?
(ii) A farmer wants to conserve water for irrigation. State two (2) ways
use efficient irrigation
system.