1. Explain what is meant by the term "trophic level", and state what the first trophic level in a food chain is.
Answer
Any level in a food chain or web. The first trophic level is almost always a producer (that photosynthesises).
2. Define the term "apex predator".
Answer
Consumers that kill and eat other animals, for example, fox, lion, shark.
3. Name the process that removes carbon from the atmosphere in the carbon cycle.
Answer
That process is photosynthesis.
4. Give some examples of precipitation in the water cycle.
Answer
Rain, snow, hail or sleet.
5. Give the term used to describe the organism at the start of the food chain: grass ➜ hare ➜ lynx.
Answer
Grass is a producer.
6. Explain the importance of grass in the food chain.
Answer
Grass produces biomass, synthesises molecules and makes glucose by photosynthesis.
7. A student uses a sampling technique to investigate the distribution of a plant called Ribwort plantain. The student uses 0.25 m2 quadrat and 20 m tape measure. Describe how the student would use the equipment to investigate the distribution of plantain across a footpath.
Answer
The student puts the tape measure straight across the footpath to produce a transect then puts the quadrat at 0 m and counts the number of plantain found in the quadrat. The student then moves the quadrat along the tape measure at 2 m intervals and counts the number of plantain in each quadrat. The student then moves the tape measure along the path to create a new transect parallel to the first and repeats the sampling at least three times.
8. Give some reasons for changes in environmental conditions.
Answer
Human activity can change environmental conditions. Seasonal changes occur; for example, swallows migrate from Europe to Africa in the winter. Geographic changes also occur; for example, the mosquito that acts as a vector for malaria is found in tropical and subtropical regions of the world, but its distribution could shift with rising global temperatures.
9. Explain what transpiration is.
Answer
The loss (evaporation) of water from a plant through its leaves and stomata.
10. Give some conditions that will cause rapid decay of waste biological material.
Answer
More oxygen, higher temperature, more water (moisture), more decomposers (microorganisms).
11. Waste biological material can be put into a biogas generator to produce biogas. Explain what happens to the waste material in a biogas generator.
Answer
No oxygen so anaerobic decay takes place producing methane gas that can be used as a fuel.