Aqa essay biology

Large store of myoglobin, Supply of glycogen, Rich supply of blood vessels, Numerous mitochondria Fast-twitch — Contracts more rapidly with more Aqa essay biology but only for a short period of time.

This allows energy to be conserved. A greater concentration of IAA builds up on the shaded side of the shoot 5. The IAA is initial transported to all sides as it begins to move down the shoot 3.

Biology Aqa

Can remove cell debris and are associated with nerve regeneration. They also affect blood pressure and neurotransmitters. An intermediate neuron 3. V ration Therefore mammals and birds in cold environments are relatively large Smaller extremities e.

However in this case it slows down growth rather than speeds it up. Controls under normal resting conditions The two divisions are antagonistic meaning that their effects oppose one another Control of heart rate Changes of the heart rate are controlled by a region of the brain called the medulla oblongata which has two main divisions One division is connected to the sinoatrial node through the sympathetic nervous system The other is connected to the sinoatrial node via the parasympathetic nervous system Control by chemoreceptors Chemoreceptors are found in the wall of the carotid arteries and detect hanges in pH as a result of CO2 concentration When CO2 concentration in the blood is too low, chemoreceptors detect the drop in pH and send impulses to the section of the medulla oblongata responsible for increasing heart rate This section then increases the number of impulses sent to the S.

This is not a synoptic approach. The essay is not just a memory test of what a student knows — it is also a test of whether they have some understanding of what they have learnt and can apply what they know.

In doing so they relieve pain. The response is quick, yet short lived and only acts on a localised region of the body.

V ratio so smaller animals are found in warmer climates Larger extremities Light coloured fur to reflect heat Vasodilation — Arterioles increase in diameter, more blood reaches capillaries, more heat is Aqa essay biology radiated away Increased sweating — Heat energy is required to evaporate sweat water.

Coordinator intermediate neuron 6. The responses due to secretion of hormones often act over a longer period of time, yet are slower to act. The peripheral nervous system PNS — Made up of pairs of nerves that originate either from the brain or the spinal cord The peripheral nervous system This is divided into: A fibrous protein arranged into the filament called the tail 2.

Histamine causes dilation of blood vessels, increased permeability of capillaries and therefore swelling the infected area. It is a self-propagating wave of electrical disturbance that travels along the surface of an axon membrane.

This is achieved by using the energy of a stimulus into a nerve impulse called a generator potential. Can sometimes change colour to alter heat that is radiated Regulation of body temperature in Endotherms Most heat gained through internal metabolic activities Temperature range — 35 — 44 oC — Compromise between higher temperature where enzymes work more rapidly and the amount of energy needed hence food to maintain that temperature Conserving and gaining heat in response to a cold environment Long term adaptations: The demands for scientific content, breadth, relevance and scientific terminology are now found within each level.

Having hicker and more numerous myosin filaments, having a high concentration of enzymes used for anaerobic respiration, a large store of phosphocreatine to provide phosphate to make ATP Neuromuscular junctions Many neuromuscular junctions are spread through the muscle for simultaneous contraction Each muscle fibre has one motor neuron associated with it.

Cells in the tip of the shoot produce IAA, which is then transported down the shoot. The shaded side of the root therefore grows faster, causing the shoot to bend towards the source of light IAA can also effect the bending of roots towards gravity.

It ensures that an action potential can only be propagated in one direction — An action potential can only move from an active region to a resting region. When an action potential reaches the presynaptic knob, calcium channels open allow calcium to diffuse into the presynaptic knob 2.

Therefore generating a new action potential Inhibition Some postsynaptic membranes have protein channels that can allow chloride ions to diffuse into the axon making it more negative than usual at resting potential.

They release due to injuries and increase the permeability of capillaries.Assessment guides: essays We’ve created these essay resources to support your teaching of the new AS and A-level Biology specifications and help you prepare students for the essay in A-level Paper 3.

Essay B.

10 (b) A cycle is a biological pathway or process in which the end product of one cycle becomes the starting point for the next. Write an essay about cycles in biology.

Tips on how to answer the AQA A-level Biology Extended Essay. Please share and like. 8 – Genetic fingerprinting43 Section 9. 1 – Sensory Reception • A stimulus is a detectable change in the internal or external environment of an organism that produces a response. The ability to respond to a stimulus increases an organism’s chances of survival.

• Receptors transfer the energy of a. Aug 06,  · hiya, im trying to prepare for the synoptic essay for AQA Biology A on the 18th june (eeek!) but i dont have anything to compare my essays to.

does anyon. Complete lesson to prepare students for the Synoptic Essay AQA Biology A paper 3 for new AQA Biology syllabus. Includes sample essay for students to mark, a marksheet to assess students essays and a list of past essay titles and their markschemes.5/5(5).

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Aqa essay biology
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