(a) State five processes involved in the water cycle.
(b) Name one instrument used for measuring each of the following physical factors:
(c) Explain briefly the contributions of the following scientists to the formulation of the cell theory:
(d) What is meant by each of the following terms:
(e) Make a diagram, 6 cm – 8 cm long of the human tongue illustrating the four areas of taste.
(f)(i) List four ways through which microorganisms enter the human body.
(ii) State three harmful effects of microorganisms to humans.
(a) Processes involved in water cycle
(b) Instruments for measuring the following physical factors
pH – pH meter/pH paper/ colorimeter;
Light intensity – light meter/photometer;
Turbidity – Secchi disc;
Temperature –thermometer.
(c) Contributions to cell theory
(i) Robert Hooke: He discovered the cell; while using a microscope to examine the cork from a tree bark; he observed honeycomb structures/dead cell walls surrounding empty holes; which he called ‘cells’.
(ii) Theodore Schwann: Examined bits of different animals under the microscope; and observed that all animals are composed of cells.
(d) (i) Nastism
Refers to the non-directional response of plant organs/part of a fixed plant to external /non-directional or diffused stimuli/touch/temperature/humidity/( e.g. leaves of Mimosa plant folding up when touched); it is not a growth movement; it is reversible (e.g. 4-0-clock flower).
(ii) Taxism
It is not a growth movement; directional response of motile/whole organisms; towards / away from to an external stimulus/ light/ chemicals/ temperature; (e.g. Euglena swimming away from chemicals; Euglena swimming towards light, etc.)
(e) Diagram of the human tongue showing areas of taste
(f) (i) Ways through which microbes enter the human body
(ii) Harmful effects of microbes to humans
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