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At what stage of Meiosis are the centrioles of paired chromosomes at opposite poles of the cell ?

During Meiosis I: Metaphase I
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Describe how water moves from roots to leaves.

By the transpiration stream, in the xylem.The xylem is the tube in the plant in which water and solutes are transported from the plant roots to the stem and leaves. The xylem allows capillary action, which c...
RK
Answered by Rachel K. • Biology tutor
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Describe the sequence of events which allows information to pass from one neurone to the next neurone across a cholinergic synapse. (6 marks)

(1) An impulse causes calcium ions to enter the axon. (2) Vesicles fuse with the presynaptic membrane. (3) This causes the release of acetylcholine. (4) Acetylcholine diffuses across the synaptic cleft. (5) ...
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Why do veins have valves and why don't arteries have them?

The heart pumps the blood into the arteries with a very high pressure and the blood can therefore travel through them to the tissue of interest. The arteries are also very elastic, therefore they can pulsate...
AC
Answered by Ana C. • Biology tutor
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Outline how crossing over and random orientation promotes genetic variation.

crossing over and random orientation of chromosomes occurs in Meiosis I;o Random orientation: ▪ Random orientation of homologous chromosomes creates genetic variation. ▪ There are over 8 million ways that ch...
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