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Describe and explain the process of protein synthesis. (6 marks)

Transcription is the first step of protein synthesis. This involves DNA helicase unwinding the double stranded DNA, and complementary mRNA binding to the DNA bases with the help of the DNA polymerase. DNA li...
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Answered by Ben S. • Biology tutor
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Describe and explain what is meant by ‘natural selection’. (4 marks)

Natural selection is a theory devised by Charles Dickens. Due to the existent of alleles and genetic variation, some organisms will be better adapted for survival in their given habitat. As a result of this ...
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Answered by Charlotte G. • Biology tutor
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Describe and explain the adaptations of the alveoli for gas exchange. (4 marks)

The alveoli are highly folded in order to increase the surface area available for gas exchange. The thins walls of the alveoli and the supplying capillaries allow for a short diffusion distance, thus increas...
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Answered by Charlotte G. • Biology tutor
39688 Views

What are the main differences between meiosis and mitosis?

Both mitosis and meiosis are processes of dividing a diploid cell, however there are a number of key differences. Mitosis results in two genetically identical, diploid, daughter cells and takes place during ...
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Answered by Kara E. • Biology tutor
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Describe and explain how an action potential is generated (6 marks)

The membrane is at resting potential, -60mV inside compared to outside. It is polarised . 2. Na+ ion channels open and some Na+ ions diffuse into the neurone. 3. The membrane depolarises - it become less neg...
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Answered by Rokshan E. • Biology tutor
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