Search over 10,000 free study notes

• Thin alveolar walls for O2 and CO2 to travel through - To travel across the membrane, gases have to be dissolved, so the alveolar walls are moist - Large surface area to volume ratio allows for maxi...

There are three key factors affecting rate of photosynthesis at GCSE level. They are light intensity, CO2 concentration, and temperature. These factors are best visualised by drawing graphs with rate of p...

Eutrophication occurs when nitrate fertilisers are carried by ground water into lakes and ponds. The fertliser encourages algal growth in the water, which in turn blocks out sunlight. This causes submerge...

Hydrogen Bonding occurs between 2 adjacent molecules of H₂O.

The polar covalent bond between oxygen and hydrogen creates negative and positive partial charges respectively.

There ...

Lumen sizes in blood vessels differ due to the differing functions of the vessels themselves.

Arteries have to carry oxygenated blood away from the heart to the tissues at high pressure. Small lume...