5.4 understand the reasons for pest control and the advantages and disadvantages of using pesticides and biological control with crop plants

- Pesticides
Advantages: Very effective, easy to apply, easy to obtain

Disadvantages: Toxic (kill other plants and can harm humans), Bio accumulation, Resistance (Mutation in the pests - leads to resistance)

- Biological Control
Advantages: No toxic chemicals, Less impact on wildlife

Disadvantages: Not 100% effective, Difficult to control, difficult to match a predator to prey, it can take a long time

5.3 understand the use of fertiliser to increase crop yield

- Fertilizer is any organic or inorganic material of natural or synthetic origin (other than liming materials) that is added to a soil to supply one or more plant nutrients essential to the growth of plants
- Are nitrate and phosphate
- Divided into two groups: organic and artificial
- Organic: animal waste, cow facades, decomposition.
- Artificial: chemical

5.2 Understand the effects on crop yield of increased carbon dioxide and increased temperature in glasshouses

- Rate of photosynthesis =CO2 + H2O----> glucose + oxygen
- Increased concentration of CO2 is substrate
- Higher increase of temperature leading to increase of the rate of reactions
- OPTIMUM: Peak of which something works at its very best

5.1 Describe how glasshouses and polythene tunnels can be used to increase the yield of certain crops

- Light penetrates through the glass into the internal surfaces
- Light is absorbed by surfaces inside the glasshouse (eg. Plants, Wood and soil)
- The surfaces would re emitted as heat, heats warm the air
- The heat warms the air, raising its average kinetic energy causing the temperature to increase
- Warm air becomes trapped inside the glasshouse

2.89 understand the sources, roles and effects of the following hormones: ADH, adrenaline, insulin, testosterone, progesterone and oestrogen

ADH:
- Source: Hypothalamus.
-Promotes water conservation the kidneys.

Insulin:
- Source: Made by cells in the pancreas.
- Lowers blood glucose levels

Adrenaline:
- Source: Adrenal gland.
- Readys body for physical fight or flight response
- Increases heart rate

Testosterone:
- Source: Testes gland.
- Controls development of male (Puberty)

Oestrogen:
- Source: Ovary gland.
- Controls development of female (Puberty)

Progesterone:
- Source: Ovary gland.
- Regulates menstrual cycle (women)

2.88 describe the role of the skin in temperature regulation, with reference to sweating vasoconstriction and vasodilation

- Core temperature is controlled by Hypothalamus.
- The skin regulates body temperature to protect against hyperthermia and hypothermia.
- Skin is responsible for temperature regulation within our body. The core temperature of our body is 37 C.
Vasoconstriction
- capillaries narrows, so they carry less blood. This keeps heat inside the body, reduces sweating.
- Hair erection.
- Shivering.
- Insulation (from a layer of fat under the skin).

Vasodilation
- Capillaries widened so more blood can be carried to the surface. heat transferred out of the body through conduction and radiation.
- Sweating
- Hairs lay flat

2.86 Describe the structure and function of the eye as a receptor, 2.87 understand the function of the eye in focusing near and distant objects, and in responding to changes in light intensity

Structure:

1. CORNEA
2. EPITHELIUM
3. IRIS
4. PUPIL
5. RETINA
6. SCLERA
7. LENS

Sight is the transmission of light signals through nerve endings to the brain, which interprets the signals and produces visions of what is seen.

- Light enters the eye first through the cornea
- The pupil is the opening that controls how much light passes from the cornea to the lens. The iris, the colored portion of the eye, is actually two sets of muscle fibers that control the size of the pupil.
- Light travels from the lens through a chamber filled with vitreous humor, a semi-solid that helps the eye keep its shape.
- The retina is the back of the inside of the eye and contains light receptors. The receptors are nerve endings with a direct link to the brain via the optic nerve.
- Receptors in the eye consist of rods and cones. Rods detect light regardless of wavelength and help the brain determine light intensity, whether it is bright or dim.
- Cones are only active in bright light and are particular to red, blue, or green. Each type of cone detects a particular light wavelength.