5.11 Breeding Animals

5.10 Breeding Plants

5.9 Fish Farming

5.8 Fermenter

5.7 Yoghurt

5.5 Beer Production

5.4b Biological control

5.4a Pesticides

5.3 Fertilisers

5.2 Crop Yield

5.1 Glasshouses

2.89

2.88

 

2.88  Describe the role of the skin in temperature regulation, with reference to sweating vasoconstriction and vasodilatation

Hot (Can be detected by hypothalamus)

Blood vessels on your skin’s surface widens allowing more blood to flow to the surface thus more heat is lost through radiation

Sweat glands in your skin produce sweat, this evaporates and cools you down

Cold:

Blood vessels on the skin’s surface close up, cutting down the flow of blood to the surface and less heat is lost by radiation

Sweat glands stop producing sweat

When shivering the muscles start to contract quickly produces extra heat that warms the body

The hair erector  muscles contract and the hair  is pulled upright. This  would trap a layer of air  -which is a poor conductor of heat therefore it insulates your body

Vasodilatation is where  blood vessels widen  resulting from the relaxation of smooth muscle cells (especially in the large veins and arteries), this process is opposite to vasoconstriction which involves the narrowing of blood vessels

2.87 Function of the eye

2.86 Structure of the eye