A Level Circulation in animals OCR ExamBuilder

Fractional Distillation Revision Questions

The oil sands contain between 10 to 15% of crude oil. This crude oil is mainly bitumen. In Canada the oil sands are found in the ground underneath a very large area of forest. The trees are removed. Then large diggers and trucks remove 30 metres depth of soil and rock to reach the oil sands. The oil sands are quarried. Boiling water is mixed ...

  Sand, Fractional, Distillation, Salon id, Fractional distillation

A level Biological Molecules practise OCR ExamBuilder

Protein structure can be represented at four levels: primary, secondary, tertiary and quaternary. Below is a set of features that may be used when describing the structure of a protein such as haemoglobin. Features Letter hydrogen bonds A peptide bonds B α and β subunits C the sequence of amino acids D the initial folding of the polypeptide ...

  Biological, Primary, Molecules, Secondary, Tertiary, Tertiary and quaternary, Quaternary, Biological molecules

5.5 Plant and animal responses OCR ExamBuilder

Answer all the questions. 1(a). Fig. 20.1 is a flow diagram that shows the sequence of events in the body once a threat is perceived. The response is often described as the ‘fight or flight’ response as it prepares the body to respond physically to the

  Animal, Response, Plants, Plant and animal responses ocr

Redox Titrations - QP OCR ExamBuilder

2(a) Chromite is the main ore of chromium. The chromium-containing compound in chromite is Fe(CrO. 2) 2. The percentage of chromium in a sample of chromite can be …