Summer 2016 selection (b)

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Importance of constant core temperature in mammals

Mammals are hot-blooded and so they don't receive their energy from the sun

Enzymes work at an optical temperature

Explanation of action of brown adipose tissue raising core temperature

This sends heat to the insulation layers increasing core temperature

When temperature drops below core the rat must be respiring

Adipose tissue acts as an insulator and increases the diffusion pathway

Electrical activity in neurones increases. This suggests that synapses are being sent to the rat's thermoregulatory centre.

Hot skin is picked up by skin receptors

Comments on data about behaviour of herbivores

There is an overlap between wildebeest and impala

The impala is the herbicide that spent more time in the area with many predators

Less time feeding so less time respiring

Less energy to grow ATP

Herbivores eat crops which reduces agricultural productivity

Heterozygous mice

They have half the allele to the normal mice

Explanation of plants transformed by recombinant DNA technology synthesising an insect protein

Because the genetic code is universal, all organisms and species are able to insert triplet sequences into the DNA of another

Proteins are made from specific amino acids in groups of three called codons. These amino acids are universal

The inserted gene is not seen as a foreign antigen

The DNA code is degenerate - all base pairs are the same in all organisms

The plant is now producing proteins that contain the desired gene from the insect

Control of heart rate

Barrow receptors detect changes in pressure

DNA probes explained

This enabled them to see visually which probe attached

Reason for using a type of microscope

This gives intense zooming abilities

It uses correct wavelength to see

Em can see inside cells

Calculation of percentage of mitochondria with unusual structure

By counting the unusual mitochondria then diving by the total

Count the number of normal ones and unusual ones in a cell and divide by each other    Home     Contents     Contact via form     Contact via email     Howlers     Books     WWWlinks     Terms of use     Privacy