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Why are organisms within a species genetically different?

1) Crossing over - in Prophase I of meiosis, non-sister chromatids in the same bivalent (i.e. chromatids on separate chromosomes within a homologous pair) can exchange alleles, creating new combinations. 2) ...
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Answered by Katherine F. Biology tutor
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What is transcription?

Transcription is the formation of an mRNA molecule from its complementary DNA template. First the enzyme DNA helicase unwinds the double helix, and the hydrogen bonds between complementary bases break. This ...
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Answered by Katherine F. Biology tutor
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What evidence is there to support the delocalised model of benzene over Kekulé's model?

Bond lengths - a single bond is 0.153nm while a double bond is 0.134nm, making Kekulé's model of alternating single and double bonds asymmetric. Other evidence shows benzene to be symmetrical so it cannot ha...
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How do ionic charge and radius affect lattice enthalpy?

As the charge of an ion increases, so does its charge density. The ion can therefore form stronger electrostatic forces of attraction, resulting in stronger bonds. As these bonds form to produce a lattice st...
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How do auxins bring about positive phototropism in plants?

Phototropins are enzymes found in the plasma membrane of particular cells. They are phosphorylated when hit by blue light. 2) This phosphorylation triggers the movement of auxin across the plant shoot by act...
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Answered by Katherine F. Biology tutor
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