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Outline the process of meiosis.

There are two main parts to meiosis - meiosis I and meiosis II. In meiosis I, crossing over of homologous chromosomes occurs during prophase I, allowing exchange of genetic material between the two parental ...
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Answered by Kate C. • Biology tutor
8551 Views

How is the alveoli adapted for its job?

The ruched, cloud-like structure of the alveoli means that there is a large surface area for gas exchange between the blood and the lungs, which increases the efficiency of the process, meaning the supplies ...
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Answered by Phoebe A. • Biology tutor
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What are enzymes and how do they work?

Enzymes are small proteins found in living organisms. They are described as biological catalysts, meaning they speed up reactions and remain unchanged at the end, ready to do the same again. They are vital f...
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Answered by Isabel M. • Biology tutor
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Why do organs need to be 'matched'?

The antigens present on the cell surface membranes of organs are different from person to person due to genetic variation (leading to protein tertiary structure variation - remember antigens are proteins and...
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Answered by Frances E. • Biology tutor
2902 Views

Why do large organisms need specialised exchange systems and what are the features of an efficient exchange surface?

Large organisms have-High metabolic activity (used in movement, respiration, reproduction etc)Large distance between cells and the incoming oxygen that they requireA very small surface area to volume ratio m...
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Answered by Abigail J. • Biology tutor
13190 Views