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(b) Cigarette smoke contains nicotine. Nicotine is a vasoconstrictor that reduces the diameter of some blood vessels. (i) Using this information, explain why smoking increases the risk of developing cardiovascular disease (CVD). How do I approach this?

Good question. You must think about these questions in progressive steps. The first step is given - vasoconstriction. What does this cause? A reduction in the diameter of the blood vessel. So you've got t...

Answered by Michael A. • Biology tutor

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Why is genetic drift important in small populations?

Within a population there is genetic variation between individuals. For example, individuals have different combinations of different alleles, which may or may not be passed onto their offspring. Genetic ...

Answered by Bethany P. • Biology tutor

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mRNA is used during translation to form polypeptides. Describe how mRNA is produced in the nucleus of a cell. (6)

The first step in biology is always to make sure you understand and always use specialist biological terms - it's often said you almost learn more vocab in biology A level than you do in French, ...

Answered by Omar E. • Biology tutor

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Describe the structure and bonding that contributes to a functional protein.

Translation of an mRNA transcript by ribosomes produces the two-dimensional primary structure – a linear sequence of amino acids held together by

Answered by Edwin J. • Biology tutor

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Name 2 forms of epigenetic modification, and explain the effect they have on the genotype.

Acetylation: addition of an acetyl group to a histone molecule. Forces DNA strands apart, allowing easier access for RNA polymerase for transcription. Therefore increases expression of target gene(s) due ...

Answered by Nick G. • Biology tutor

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