Observation

This question was compulsory.
Question 5(a)was well attempted. Chemosynthesis was well defined.
In 5(b), the conditions necessary for the rate of primary production in green plants was well stated.
In 5(c),the modes of nutrition in plants were well answered but candidates lost marks to spelling errors.
In 5(d),examples of plants that exhibit the modes of nutrition was well answered but marks were lost to spelling errors.
In 5(e),the questions were well attempted except for the relationship between the functions of the tongue and the organ associated with the olfactory lobes.
Question 5(f)was well attempted as the candidates could define courtship and explain the courtship behaviour in domestic fowl.

The expected answers are:
(a) Chemosynthesis
Is the oxidation of inorganic substances /hydrogen sulphide; ammonia/methane/iron; as a source of energy into organic substances; without sunlight/solar energy.

(b) Conditions that would affect the rate of primary production in green plants

• Rate of biomass accumulation/organic materials/dung/wood;
• Rate of photosynthesis/rate of consumption of CO2/ production of O2.
  (c) Modes of Nutrition in plants

• Autotrophic/holophytic/photosynthetic
• Carnivorous/parasitic plants
• Saprophytic
• Chemosynthetic                                                                           

Note: spellings must be correct to score.                                       

(d)  Examples of each plants that exhibit the modes of nutrition mentioned in 5(c)

• Autotrophic/holophytic/photosynthesis: Green plants/any two correctly named green plants/Spirogyra.
• Carnivorous/parasitic plants: Venus flytrap; pitcher plant; Bladderwort/any correctly named example/Dodder, Wort; Mistletoe.
• Saprophytic: e.g. Mucor; Rhizobium; Mushroom.
• Chemosynthetic: Bacterium; Nitrifying Bacteria; Iron Bacteria.

Note: spellings must be correct to score.                                 

(e) (i) Function of the Olfactory lobes in humans
They contain olfactory nerves that are involved in smelling/odour.

(ii) Location of olfactory lobes
(Anterior end of the) cerebrum of the brain

(iii) Sense organ associated with the olfactory lobes in humans
Nose                                                                                       

(iv) Relationship between the functions of the Tongue and the Nose
The function of tongue is tasting; and the function of the nose is smelling; the two sense organs / nose and tongue are interconnected sense organs; the sense of smell and taste are chemical; and work together/taste receptors on the tongue work with the smell receptors /odorants in the nose.                                                                                                                                     

(f)(i) Courtship behavior in animals
Is referred to as instinctive/particular/specific actions/activities; exhibited by animal/of opposite sex; to seek a compatible mate; for copulation/reproduction; through visual/auditory chemical signals/stimuli.

(ii) Courtship in Domestic Fowl

• Takes the form of pairing;
• the male displays its brightly-coloured feather/ attractive colour/plumage;
• sideways dance/waltzing/ scratching the ground;
• during pairing the male picks up food and drops it for the female to eat;
• cock pecks the head of hen;
• mounts her and copulation takes place.                           

(g) Structural features of a worker honeybee that enables it to adapt to its environment

• proboscis/mouthparts have a central tube; through which small amounts of nectar can pass by capillarity/sucked in;
• hairy/sticky body of bees to collect pollen grains;
• pollen comb on the fore legs; for clearing pollen at the head region;
• pollen basket on the hind legs; where pollens collect;
• brush on the tarsus of the hind legs; used to sweep pollen – from the body into the pollen basket;
• prong on tibia of the middle legs; used to scoop out pollen from the pollen basket.