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Biology
A Level

Explain how an adult develops immunity to a bacterial toxin

When the body is exposed to a bacterial toxin for the first time, it is recognised as foreign and an immune response will be mounted. In response to the toxin, B lymphocytes will be produced which make an...

Answered by Biology tutor
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Why could a single base mutation stop an enzyme from catalysing a reaction?

Because the single base mutation would change the primary structure of the enzyme which in turn would change the secondary structure of the enzyme due to the differences in hydrogen bonds formed. As a res...

Answered by Biology tutor
2419 Views

Describe how mutations in tumour suppressor genes can lead to the development of tumours

Tumour suppressor genes (TSGs) are genes whose protein products restrain inappropriate cell growth and division. A mutation results in a changed amino acid sequence, which alters the tertiary structure of...

YP
Answered by Yva P. Biology tutor
4039 Views

What are the stages of the cell cycle?

Interphase and Mitosis make up the cell cycle.Interphase includes 3 phases- G1- Cell growth phase and this is where cell multiply their organelles and their cytoplasms expand;S phase- DNA synthesis phase ...

JB
Answered by Jade B. Biology tutor
3711 Views

Explain how oestrogen can lead to the development of breat cancer

Oestrogen is a lipid soluble molecule, so it diffuses into the cell across the plasma membrane. It then binds to a recptor inside the cell and this causes it to relocate to the nucleus. The receptor then ...

JM
Answered by James M. Biology tutor
2879 Views

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