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Outline the control of the heartbeat in terms of myogenic muscle contraction, the role of the pacemaker, nerves, the medulla of the brain and epinephrine (adrenaline).

The heart muscle can contract by itself , without the stimulation of a nerve. This is called myogenic muscle contraction. The region that initiates each contraction is found in the wall of the right atrium a...
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Explain two examples of evolution in response to environmental change; one must be antibiotic resistance in bacteria.

Antibiotic resistance in bacteria is a common problem. It results from the transfer of a gene that gives resistance to a specific antibiotic usually by means of a plasmid to a bacterium. Some bacteria will t...
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Outline the consequences of a global temperature rise on arctic ecosystems.

· Changes in arctic conditions (arctic ice cap may disappear, permafrost will melt during the summer) · As the ice melts, sea levels will rise and flood low lying areas of land. · Expansion of temperate spec...
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Outline the precautionary principle.

The precautionary principle holds that, if the effects of a human-induced change would be very large, perhaps catastrophic, those responsible for the change must prove that it will not do harm before proceed...
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Analyze the changes in concentration of atmospheric carbon dioxide using historical records.

Recent Trends: ▪ Atmospheric carbon dioxide concentrations have been measured at the Mauna Loa atmospheric observatory in Hawaii from 1958 and has since been measured at a number of different locations globa...
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