Practise Edexcel A-Level Biology AS and A2 mathematical skills by using biological data for percentages, ratios, graphs, units and standard form.
The diagram shows part of the carbon cycle.
Key
The numbers in smooth brackets ( ) show the mass of carbon in petagrams found in either the atmosphere, plants or surface ocean.
The numbers in square brackets [ ] show the mass of carbon in petagrams transferred between the atmosphere and the plants or surface ocean per year.
A petagram is equal to grams.
The mass of carbon recycling between the atmosphere and the plants, and the atmosphere and the oceans, are roughly balanced.
Calculate the increase in the mass of carbon in plants as a result of carbon exchange between the plants and the atmosphere in one year.
Give your answer in kilograms.
Answer. kg
Coral reefs are one of the Earth's most diverse biological environments.
They are thought to cover of the planet.
It is estimated that by 2030,90% of coral reefs will have been damaged by anthropogenic activities.
The photographs show an undamaged coral reef in the Maldives and a damaged coral reef elsewhere.
Undamaged reef
Damaged reef
Calculate the area of undamaged reef likely to remain in 2030.
Give your answer in standard form.
Answer
Another method being developed to restore damaged coral reefs uses 'reef carpets' (RC).
The diagram shows coral RCs.
Three types of coral were each grown on a RC.
The coral RCs were left on the seabed and monitored for 17 months.
The scientist developing this method monitored the health of the coral and the diversity of fish that were present on three types of coral, A, P and S.
The graph shows the diversity of fish present with these types of coral RCs.
Diversity of fish
State two conclusions that can be made about the diversity of fish on these three types of coral.
(2)
Nematodes are a type of worm that live in a wide range of environments.
The photograph shows a nematode.
In 1986, there was a nuclear power plant disaster resulting in high levels of radiation in the surrounding area.
Scientists have been studying nematodes in the area affected by radiation (the exclusion zone).
The exclusion zone is an area with a radius of 18.6 miles from the nuclear power plant.
Calculate the area of the exclusion zone in .
1 mile .
Give your answer to a suitable number of decimal places.
Answer
Mycobacterium tuberculosis (Mtb) and human immunodeficiency virus (HIV) are two pathogens that infect people. When people infected with either pathogen become infected with the other pathogen the disease is worse.
In one year, it was estimated that 33.4 million people were infected with HIV. It was estimated that 30% of these people were also infected with M t b.
Calculate the number of people with both infections. Give your answer in standard form.
The graph shows the number of people who have TB and the percentage of the population who have HIV. Each plotted point represents data from a different country. Number of people who have TB per 100000 population
Comment on the relationship between the number of people who have TB and the percentage of people who have HIV.
Describe how the strength of the relationship between the number of people who have TB and the percentage of people who have HIV could be determined.