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Why is sickle cell disease most common among people living in tropical regions, and their descendants?

Sickle cell disease is caused by a recessive allele of the haemoglobin gene. When two copies are present (i.e. it is homozygous), many red blood cells become sickle-shaped, leading to disease. However, if on...
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Answered by Sean G. • Biology tutor
18997 Views

What are some good revision strategies?

Everyone has their own ways of remembering things, but there are some good general points that might help you out. If you just read over things, you might find that you can’t remember much at the end of a se...
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Answered by Gyda F. • Biology tutor
5208 Views

How do new species evolve?

Allopatric speciation: New species appear when one interbreeding population is split into two reproductively isolated populations, which then evolve to become separate species. This mostly happens when popul...
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Answered by Gyda F. • Biology tutor
9890 Views

Describe the process of translation.

Translation is a universal process in biology where a protein formed of amino acids is made by using messenger Ribonucleic acid ( mRNA ) to dictate the order of amino acids. Following transcription (the conv...
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Answered by Ivan T. • Biology tutor
34066 Views

How does mitosis produce two genetically identical nuclei?

Mitosis is the process by which cells reproduce. It occurs during the M-phase of the cell cycle. At this point, each chromosome consists of two identical sister chromatids, which were formed by DNA replicati...
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Answered by Erin B. • Biology tutor
24957 Views