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Biology

A Level

Describe the steps involved in mitosis and name the exact stages (6)

Interphase: DNA and organelles replicate 2) Prophase: Chromosomes condense (and become visible! - made up of two sister chromatids joined by centromere), nuclear membrane breaks down, and centrioles...

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Outline the process of the light independent reaction in photosynthesis, also known as the Calvin cycle.

Light INDEPENDENT reaction:· RuBP combines with CO₂, using Rubisco which is an enzyme that catalyses the reaction· This forms 2x GP molecules· Each GP is reduced to form TP, u...

Answered by Johana A. • Biology tutor

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Describe how the Meselsohn- Stahl experiment was set up. Describe how the results of the Meselsohn- Stahl experiment provide evidence for semi- conservative replication

Describe how the Meselsohn- Stahl experiment was set up. • Culture E. Coli for several generations with amino acids containing 15N. Incorporate 15N into DNA • 15N bacteria washed and tran...

Answered by Jake C. • Biology tutor

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Describe how bacteria are used to genetically modify crops. Describe two examples of GM crops. Describe the reasons why some are opposed to GM crops

Describe how bacteria are used to genetically modify crops.• Certain bacteria (Agrobacterium) can cause plant cells to multiply and form tumours by inserting plasmid DNA into genome of pl...

Answered by Jake C. • Biology tutor

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Describe 2 ways mutations can occur

• DNA not copied properly before cell division: mistakes in copying; small errors - gene/point mutations • Chromosomes damaged/break: usually repair; but may repair incorrectly - large changes in may gene...

Answered by Jake C. • Biology tutor

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