Biology Theory a.    Classify  the following biological associations under the headings in the table below:     (i)…

a.    Classify  the following biological associations under the headings in the table below:
    (i)  Remora and shark;
    (ii)  Lichen;
    (iii)  Cattle and white Egret;
    (iv)  Tapeworm in the gut of humans;
    (v)  Flowers and Honeybees; 
    (vi)  Mistletoe and Cacao plant.

                        [6 marks]

b.    (i) State three adaptive features of parasites.    [6  marks]
    (ii) State two effects of parasites on their hosts.    [2 marks]

c.    (i)  What are saprophytes?    [2  marks]
    (ii)  Give four examples of saprophytes.    [4  marks]

Explanation

b. (i)  Adaptive features of parasites
    – possession of specialised organs/haustoria/suckers/hooks; for attachment to the surface of the body of the host;
    – specialised piercing/sucking mouthparts; for sucking fluids/blood/plant juices;
    – hermaphrodite/ability to reproduce rapidly/easily in large numbers/large quantity of eggs are  produced; to propagate their lineage/species;
    – large surface area; for absorption of digested food;
    – possession of special features/structures/cuticle; to withstand harsh environment/conditions/being digested.

   (ii) Effects of parasites on their host
    Absorption of nutrients from the body of the host can:
    – lead to stunted growth;
    – lead to low resistance to diseases in the host;
    – lead to loss of blood;
    – lead to loss of weight;
    – lead to septicaemia;
    – cause diseases/injuries/harm;
    – lead to death;
    – de-value the worth of animal skin/hides/ reduce the value of farm animals.

c. (i)  Saprophytes
    are organisms that feed; on dead/decaying/decomposing organic matter.

   (ii) Examples of saprophytes
    – Fungi/Bacteria/
    – Mushroom
    – Azotobacter
    – Rhizopus;
    – Clostridium
    – Mucor
    – Streptomycetes
    – Toadstool
    – Mold/mould
    – Penicillium
    – Saccharomyces
    – Aspergillus
    – Yeast.