Plants are classified together in a kingdom. Other organisms are classified in other kingdoms. Outline the value of classifying organisms [4]

a) Shows how organisms are related

b) Helps cope with the large number of organism

c) Easier to store/find information

d) Easier to find useful organisms (e.g. drugs in animals)

e) Makes it easier to ID organisms

f) Allows predictions to be made about the nature of a organism

g) Traces possible evolutionary links

h) ID homologous structures

Outline the consequences of rising carbon dioxide concentrations in the Earth’s atmosphere [5]

The rising carbon dioxide concentrations in the atmosphere create a blanket over the Earth which keeps the suns wavelengths in the atmosphere; this would then increase global warming as the Earth would continually heat up as it cannot escape due to the build up of gases. With increased heat come many consequences such as the melting of polar ice caps, this will then in turn cause a rise in global sea levels causing flooding in low lying areas. With the heat there can also come natural disasters such as drought which would affect agriculture leading to a decline in food production which has the consequence of decreasing life expectancy. The heat also brings about diseases from mosquitoes, such as malaria and dengue fever, because they thrive in heat. Also warmer temperatures allow pathogens to survive better.

Explain the light-independent reaction of photosynthesis [8]

The energy in the form of ATP and NADPH made in the light dependent reaction is then used in the light independent reaction to fix carbon from carbon dioxide into organic molecules. This reaction is called the Calvin cycle and it takes place in the stroma of the chloroplast and is controlled by enzymes. Firstly a single carbon in carbon dioxide is fixed with RuBP and is catalyzed by the enzyme Rubisco to form 2 molecules of Glycerate-3-phosphate. The Glycerate-3-phosphate is then reduced to triose phosphate by using the energy which comes from the oxidation of NADPH and ATP. Triose phosphate is then used to regenerate Ribulose Bisphosphate. 

The carbon cycle involves both the production and the fixation of carbon dioxide. Draw a labelled diagram to show the processes involved in the carbon cycle [5]

Explain the process of aerobic respiration including oxidative phosphorylation [8]

In aerobic respiration, glucose is split into pyruvate by glycolysis. The pyruvate then enters the mitochondria and reacts with coenzyme A by the process of oxidative decarboxylation to form acetyl CoA, in this process carbon dioxide and NADH is formed. The acetyl group then enters the kreb cycle where FAD+ and NAD+ accept hydrogen to form NADH and FADH2. The energy in these molecules is then used to make many more molecules of ATP. In the inner membrane of the mitochondria there are the proteins. Both NADH and FADH2 donate electrons to the electron transport chain. As electrons move from 1 complex to another they transfer their energy to pump protons across the membrane, this then creates a concentration gradient across the membrane. Oxygen is the final electron acceptor; it will then combine with the protons to form water. 

Describe the process of active transport [4]

Active transport is when a protein moves a certain material across the membrane from a region of lower concentration to a region of higher concentration. This means the substance is absorbed against the concentration gradient and energy is needed for this active transport to work. The energy is usually comes from adenosine triphosphate or ATP, every cell supplies its own ATP by cell respiration. Globular proteins or pump proteins or transporter proteins in membranes carry out the active transport, the membrane must contain a lot of these proteins so that the cell can control the contents of its cytoplasm precisely. An example of active transport is in human nerve cells where potassium ions are pumped in and sodium ions are constantly transported out of the cell by active transport into the external fluid bathing the cell to build up a store of potential energy or an electrical impulse that is used to transmit a nerve impulse.

Draw a diagram of the ultrastructure of an animal cell as seen in a electron micro graph [6]