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What are the requirements for natural selection?

Evolution by natural selection needs three conditions to be satisfied: variation, heredity, and competition (also called differential fitness). There must be variation in a population of a certain species. W...
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Answered by Michael C. • Biology tutor
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What is homeostasis? Describe using an example.

Homeostasis can simply be described as the maintenance of a constant internal environment. Human bodies must get rid of accumulating toxic substances which can harm the body. Things like sugar concentration ...
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Answered by Tasneem S. • Biology tutor
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Explain the flow of ions during an action potential of a typical neurone

There are numerous ionic fluxes during an action potential, which involves depolarisation, repolarisation and hyperpolarsation. During depolarisation, voltage-gated sodium ion channels open. In turn, sodium ...
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Answered by Annie S. • Biology tutor
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Explain why the contraction times of the atria and ventricles in the heart differ.

The atria have a shorter contraction time as the ventricles as they only need to pump blood into the ventricles. The contraction time of the ventricles is longer as they need to pump blood through the aorta ...
PK
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What are the similarities and differences between mitosis and meiosis?

Mitosis is the process by which a cell divides to give rise to two identical diploid daughter cells and is how all somatic cells are produced. Meiosis is the process by which a cell gives rise to four geneti...
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Answered by Natasha S. • Biology tutor
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