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What is osmosis and how does it work?

Osmosis is the movement of water across a semi-permeable membrane, down the concentration gradient. This means that if there is more water on one side of a membrane, it will move to the other side until b...

Answered by Niclas W. • Biology tutor

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Two species of frogs, each found on one of two neighbouring islands yet with the same genus, are identified. Scientists believe that the two species originated from a common ancestor. Explain how these species could have evolved.

Questions about speciation are at their core based on Darwin's theory of evolution. As a result, we must recall GCSE knowledge of natural selection to combine with the new concepts in speciation introduce...

Answered by Iqra S. • Biology tutor

2146 Views

Draw a genetic diagram to show how unaffected parents could have a son with Haemophilia but also other children who do not suffer from the disease.

First figure out the phenotype (what is visible/expressed) of parents: Normal male x Normal female Next write down their gametes: X^Hy and X^H X^...

Answered by Lucy F. • Biology tutor

3126 Views

Discuss the advantages and disadvantages of using biofuels in the UK (4).

One advantage of biofuels is that they can help to reduce CO2 emissions, by growing plants that photosynthesise, meaning any CO2 released is more balanced than with fossil fuels.Biofuels are also renewabl...

Answered by Clea S. • Biology tutor

5418 Views

DNA helicase is important in DNA replication - explain why.

DNA helicase acts to unwind the 2 strands of DNA by breaking the Hydrogen bonds between them. This means that free nucleotide bases can be attracted and bind to the exposed bases.

Answered by Rachel M. • Biology tutor

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