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Biology

A Level

What is the difference between haploid and diploid cells? (2 Marks)

Diploid cells contain 2 sets of chromosomes (23 pairs of chromosomes) e.g. body cells. Haploid cells contain half the amount of chromosomes as diploid cells (only

Answered by Katie D. • Biology tutor

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Describe the stages of the mitotic cell cycle, explaining the appearance of cells at each stage.

The cell cycle can be broken into two. When the cell is replicating its DNA and preparing for division, it is in interphase. Interphase cells have a nucleus with chromosomes arranged as c...

Answered by Hannah M. • Biology tutor

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Outline the role and organisation of the autonomic nervous system in mammals

The are two main areas of the autonomic nervous system are the sympathetic and the parasympathetic nervous systems. These are contrasting pathways and their main function is to regulate internal organ f...

Answered by Christopher T. • Biology tutor

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When a new antigen is presented to the immune system, an immune response leads to antibodies are released. The second time this happens it is much faster - explain why

In the primary immune response, there is antigen presentation followed by clonal selection, expansion and differentiation of helper t cells. This leads to plasma cells releasing antibodies and the develop...

Answered by Maxine R. • Biology tutor

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Explain the differences between active transport and facilitated diffusion.

Active transport is an active process meaning it requires the use of ATP, whereas facilitated diffusion is a passive process meaning it does not need ATP.To carry out the process active transport only req...

Answered by Niamh D. • Biology tutor

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