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How does the electrical system of the heart work?

The electrical activity of the heart begins in the sinoatrial node which is a collection of pacemaker cells located in the right atrium. These cells spread electrical activity across the atrium causing both ...
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Answered by Emma M. • Biology tutor
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What is the difference between mitosis and meiosis?

Mitosis and meiosis are both types of cell division that produce new cells, known as daughter cells, but there are some differences; Mitosis produces two identical new cells with two sets (or pairs) of chrom...
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Answered by Shannon C. • Biology tutor
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How do bacteria develop resistance to antibiotics?

When bacteria divide, random mutations in their DNA lead to differences in bacteria. Some of the bacteria will randomly develop genes that help them to survive a dose of anitbiotics (resistance). When a pers...
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Answered by Jonathan C. • Biology tutor
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What conditions are needed for evolution by natural selection to arise?

Evolution by natural selection arises when these three properties are present in a system Heredity - offspring resemble their parents in discrete characteristics. Variation - there are heritable differences ...
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Answered by Richard A. • Biology tutor
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What is the difference between Mitosis and Meiosis?

A cell has DNA and this makes up chromosomes, this is found in the nucleus of the cell. A chromosome cnan divide and form 2 chromatids. Mitosis and Meiosis are both ways in which cells reproduce. Mitosis is ...
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Answered by Simran H. • Biology tutor
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