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what are the types of speciation and how do they occur?

Sympatric speciation occurs when populations (groups) of a species that share the same habitat become reproductively isolated from each other this can be caused by numerous phenomenon. The most common is alt...
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Answered by Joshua M. • Biology tutor
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How is a sperm cell adapted to it's role?

The role of the sperm cell is to fertilise the egg. It is adapted to fulfill this role in four main ways. Firstly it has a tail to help it travel to the egg. Secondly it contains the nucleus in the head that...
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Answered by Rhys O. • Biology tutor
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What is the difference between a eukaryotic cell and a prokaryotic cell?

Eukaryotic cells include plant and animal cells. They have a cell membrane, cytoplasm and their genetic DNA is encased in a nucleus. Prokaryotic cells (bacteria) are much smaller in comparison. They have cyt...
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Answered by Isabel C. • Biology tutor
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What is the 'lock and key' hypothesis?

A reaction can only be catalysed (sped up) if an enzyme's active site matches the shape of its substrate molecules- the substrate fits into the active site like a key into a lock. This shape is highly specif...
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Answered by Emily E. • Biology tutor
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Describe active transport

Active transport is the movement of a substance against its concentration gradient across a selectively permeable membrane. In order for an organism to carry out active transport energy is required to overco...
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Answered by Alexander H. • Biology tutor
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