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Biology

A Level

Describe what is meant by the double circulation system of the heart.

The double circulatory system refers to the heart having two, connected, closed circuits. The first goes from the right ventricle of the heart to the lungs and back to heart via the left atrium. The secon...

Answered by Ibrahim M. • Biology tutor

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Describe the process of semi-conservative replication.

DNA is a double-stranded molecule with a base unit on each side held together by hydrogen bonds. A binds to T and C binds to G. DNA polymerase facilitates the localised breaking of these hydrogen bonds. F...

Answered by Nick S. • Biology tutor

2650 Views

What is the difference between DNA and RNA?

While they are both nucleic acids, there are going to be a lot of differences between DNA and RNA, starting from the names (deoxyibonucleic acid and ribonucleic acid). In terms of structure, DNA is double...

Answered by Ana-Maria B. • Biology tutor

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In a population of 1000 lemmings there are two alleles for skin colour, the dominant colour being cream (C) and the recessive being white (c). 350 individuals have white skin. Use Hardy-Weinberg to predict the number of homozygous recessive individuals.

Hardy-Weinberg Principle states that in a population of randomly mating individuals:
p + q = 1
p²+2pq+q²=1
White fur = homozygous recessive = q² = 350/100 =...

Answered by Igbunu O. • Biology tutor

2729 Views

Describe the process of mitosis

Mitosis occurs when a eukaryotic cell has exited interphaseIt occurs in 4 stages:
Prophase: The spindle fibres appear in the cell, the chromosomes condense and the nuclear membrane of the nucleus dis...

Answered by Aoife M. • Biology tutor

3283 Views