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First organisms on Earth were fully aquatic. About 460 mya a lineage of algae moved onto land and gradually adapted to air and soil. Name two evolutionary problems that first land plants faced when transitioning from water to land?

Examples of physiological problems and the adaptations of plants: Body support. As organisms in water face lower pressure than in air, algae did not need to have composite body parts. When moved onto land, p...
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Answered by Ivana L. • Science tutor
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How should I approach a source-based exam?

Analysing sources is the part of A-Level History people tend to find most difficult. So you're not alone! Unlike with essay exams, it's pretty much impossible to question-spot and prepare an answer in advanc...
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Answered by Ewan D. • History tutor
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What are the two main processes of glacial erosion and how do they work?

Firstly it is important to understand what erosion is. This is when exposed rocks are broken down by water, wind or ice and the product of this is transported away in one of the aforementioned mediums. It is...
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Answered by Hamish M. • Geography tutor
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I do not understand the concept of environmental feedbacks. Could you help explain it to me using examples?

First of all, you need to understand the difference between positive and negative feedbacks, we can then work on examples. A feedback starts with an initial perturbation/disturbance, in the case of a positiv...
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Answered by Hamish M. • Geography tutor
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How do I structure a comparative essay?

A comparative essay should be made up of equal parts of the texts or poems you are writing about, going into detail about each of the topics but also making comparisons and contrasts throughout. There are tw...
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