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The main bonding in DNA which renders the double helix structure so stable is that of hydrogen bonds. Between the complementary base pairs, hydrogen bonds connect the two strands of the helix. There are 3...

Two alpha subunits and two other subinits that vary depending on th type of haemoglobin, either beta,delta, gamma or epsilon. 

Each subunit contains on heme group. Heme group contains fou...

Start by considering what Xerophytes are, they are plants that live in dry conditions. What are the problems with dry conditions? Well, the big problem is maintaining a constant amount of water in the bod...

Anaerobic respiration occurs when there is no oxygen available and so produces an oxygen debt. This debt is equivalent to the total amount of oxygen required to oxidise the lactic acid formed from this...

Leaching is the process by which nitrates and other organic molecules can reach lakes from fields. This may be due to a large amount of fertiliser being applied or heavy rain causing the fertiliser to was...