Describe the mechanism of blood clotting in human beings. 

Undamaged blood vessels/tissues contain heparin; which prevent clotting. When the blood vessels/tissue get damage the platelets are exposed to air; making them to rapture; releasing enzyme thrombokinase/thromboplastin; which neutralizes heparin; vitamin K activates the formation of in active prothrombin; which is converted to thrombin; by thromboplastin under influence of calcium ions. The thrombin activates the conversasion of soluble fibrinogen; into insoluble fibrin. The fibrin forms a meshwork of fibres at the damaged tissues; which trap red blood cells to form a clot.

Describe the role of blood plasma

Transport red blood cells which carry oxyhaemoglobin 

Transport red blood cells which carry carbaminohaemoglobin; from the tissues to the lungs;

Transport nitrogenious wastes/urea; from the tissues to region of elimination; Acc correct region named.

Transport dissolved oxygen; from the lungs to the tissues (award from the lungs to the tissue once)

 Transport dissolved carbon iv oxide; from the tissues to the lungs ( award from tissues to lungs once).

Transports hormones; from gland which secrete them to their target organ; Acc correct hormone from correct gland to correct target organ.

Transports dissolved nutrients; from the ileum to the liver; and then from the liver to other body tissues;

Regulates the body PH; due to buffering action of its proteins;

Regulates the body temperature; by distributing heat from the liver/muscles/ other areas of production to the whole body;

Describe the adaptation of insect pollinated flowers

The flowers are large/conspicuous; to be seen from far by the insects;

The petals are brightly coloured; to attract the insects;

They have nectar that are scented; to attract the insects (award attract insect once)

They have nectar guides; to enable the insect reach the nectaries;

The anthers are firmly attached to the filament; and do not collapse as the insects brush against them as they crawl into the flower; (thus collecting pollen grains)

Pollen grains are sticky/spicky/spiny; so that they stick on the body of the insect;

The pollen grains are also larger /heavier; to avoid being carried by wind;

The stigma is sticky; so that pollen grains from the body of the insect can stick on it;

The stigma is also found inside the flower; so that they are not exposed to wind;

Some corolla are funnel shaped/tubular; to ensure insect gets into contact with stamen and carpel;

Some flowers mimicry; to attract the (male) insect;

Some have landing platforms; that ensures the insect gets into contact with both anthers and stigma