Observation

Question 6(a) was fairly answered.
Majority of the candidates drew the Carbon cycle without showing the direction of flow with arrow heads. Some candidates could not link the activities with CO2 production. Majority of the candidates answered questions 6 (c) (i) and (ii) quite well but could not show the direction of the arrows in (c) (ii), the food chain properly.

Questions 6 (d) (i) was well attempted but for bad spelling of the technical terms.

Candidates performed poorly when stating the answers to questions (e) and (f).

The expected answers are: 

6.  (a) Kidney diseases

Diseases	One effect	One remedy
Kidney stones	Abdominal pains; decreased frequency of urination; pains during urination; presence of blood in the urine; increased blood pressure.	Drink plenty of water Kidney transplant; avoid foods rich in calcium/red meat/meat; consult a physician.
Nephritis	Oedema/swelling of feet and ankle; high blood pressure; blood in urine/blood cells in urine/dizziness/back pain/fatigue;/general weakness; inflammation of the kidney tubules.	Consult a physician; kidney transplant; dialysis/all food items must be washed/cooked properly; drinking water boiled/filtered/sterilized
Diuresis	Thirst/dehydration occurs; high blood pressure may occur; loss of appetite; weakness; fatigue; nausea; loss of serum electrolyte.	Consult a physician; avoid fans/air conditions in cold weather; avoid excessive drinking of alcohol.

 

(b)

          
(c)  (i) Estuarine habitat
Is the place/point where a river enters the ocean/sea; into which the tides flow; fresh water mixes with water; to form brackish water.                                                                       

(ii) Food chain typical of an estuarine
Phytoplanktons           barnacles         fish             bird           OR
Detritus           worm               mollusc            bird                  OR
Detritus           shrimp             fish                  bird                                                                 
                                                                                                                                               
All must be correct to score
Correct sequence        (CS)                x 1 mark
Correct direction with arrow            (CD)    x 1 mark                                            
(d)  (i) Pests that can attack plant crops
Stem borer; army worms; weevils; black tea-thrips; aphids; root mealybugs; variegated grasshopper; beetle; rodents; squirrel; locust; birds; mites; cotton stainer; any correctly named examples.                
NOTE: Spelling must be correct to score.                                                              

            Diseases that can attack crops
Leaf spots; cankers; rosette; rice blast, root knots; swollen shoot of cocoa; sigatoka; black pod of cocoa; freckle; root/stem rots; bacteria blight; smut; downy mildew; powdery mildew/ any correctly named disease.
NOTE: Spelling must be correct to score.                                                              

      (ii) Ways of controlling plant diseases

Chemical control/ use of fungicides/nematicides/bactericides/pesticides;

Biological control/use of predators and parasites of insects/pests to keep them in check;

Breeding resistant varieties of crop;

Planting genetically modified crops that can resist viruses/bacteria transmitted by pests;

Destruction of infested crops by burning/deep burial/pruning of affected parts;

Destruction of alternate host

Adopt good management/crop rotation.                                                    

(e)   Functions of a public health authority

ensures cleanliness of public places/markets/schools/playgrounds;

concerned with the proper disposal of refuse;

provides maternity clinics/health centres/nursing homes/family planning;

provides child welfare services;

provides medical inspection of schools;

registers birth/death;

prevents/controls infectious diseases/administers vaccination/immunization/inoculation;

informs World Health Organization of the outbreak of infectious diseases;

ensures adequate provision of clean water to the public;

provides ambulance services;

provides quarantine services for plants/animals/humans;

gives health certificate to travellers;

provides public health education/awareness of diseases;

inspects and certifies health of animals and cleanliness of slaughter house/abattoir.                                                                                                                                                  

(f) Ways of maintaining food hygiene

proper harvesting/storage methods must be ensured to prevent damage to food items;

food items must be properly washed/cleaned to prevent contamination;

food items must be properly cooked at appropriate temperatures;

kitchen/cooking areas must be kept clean always/free from germs;

perishable food items must be properly preserved/refrigerated;

proper personal hygiene must be observed by those handling food;

cooking utensils must be properly washed/cleaned before and after use;

cooked/prepared food must be covered at all time;

proper disposal of unused/leftover food.