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Use the example of antibiotic resistant bacteria to explain directional selection.

DNA mutations happen randomly during division by mitosis. Some of these mutations code for antibiotic resistance. When a bacterial colony is exposed to antibiotics most bacteria without the resistance mutati...
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Answered by Vlad P. • Biology tutor
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How does water travel up the stem of a plant from the roots to the leaves, wouldn't gravity prevent this?

Water molecules are polar. This means that one end of the molecule is slightly negatively charged (the oxygen atom) and one end of the molecule is slightly positively charges (the hydrogen atoms). The slight...
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Answered by Lauren R. • Biology tutor
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How is blood pumped by the heart?

There are 3 main phases in the cardiac cycle: Diastole, Atrial systole, Ventricular systole 1.Diastole: -The heart fills with blood as the atria and ventricles relax. -Blood flows from the major veins(vena c...
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Answered by Victoria L. • Biology tutor
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What are the stages of mitosis?

There are 5 stages of mitosis. Prophase, Metaphase, Anaphase, Telophase and Cytokinesis. An easy mnemonic is P ee (on the) MAT C at. Prophase - 3 things occur: 1) Chromatin condenses and tightly coils to for...
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Answered by Neha K. • Biology tutor
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How does the electron transport chain work?

The electron transport chain is a collection of proteins ( complexes ), of which there are 4 types, whose purpose is to pump protons into the intermembrane space. These protons will be used by the ATP syntha...
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Answered by Cezar B. • Biology tutor
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