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19.4. Effects of humans on ecosystems
A subsection of Biology, 5090, through 19. Relationships of organisms with one another and with the environment
Listing 10 of 49 questions
Plastics are produced in very large amounts by industrial processes around the world. These plastics can enter ecosystems as pollution. The total mass of plastics produced globally in the year 2020 was 367 million tonnes. It is estimated that 3% of all plastics produced globally each year enters the ocean as plastic pollution. Calculate the total mass of plastic pollution that is estimated to have entered the ocean during the year 2020. Space for working. Some packaging is made from biodegradable carbohydrates. Microorganisms break down larger carbohydrate molecules into smaller molecules. Identify this process and name one type of microorganism that is involved. Most plastics that enter ecosystems as pollution are non-biodegradable. Describe the harmful effects of non-biodegradable plastics on both aquatic and terrestrial ecosystems.
5090_s24_qp_22
THEORY
2024
Paper 2, Variant 2
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shows a town and surrounding countryside. State the term for the effects on the environment of the activities shown in . Name a harmful gas released into the air by the factory. Describe a harmful effect of this gas. Use town woodland river sewage pipe factory prevailing wind crop plants X [T Downstream from point X in , plants in the river grow rapidly and in large numbers. State two possible reasons for this. 1. 2. Explain why, between the town and point X,there are large numbers of bacteria but very few plants and animals in the water.
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THEORY
2005
Paper 2, Variant 0
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Lake Victoria, in Africa, is one of the largest fresh water lakes in the world. It is an important ecosystem for people living around the lake who catch fish as part of their diet. shows part of a food web for the lake. Nile perch Nile sardines young Nile perch great cormorants African fish eagles humans small photosynthesising organisms prawns Nile tilapia zooplankton (not to scale) State the name of an organism shown in that is: a primary consumer both a secondary consumer and a tertiary consumer. Humans eat Nile tilapia, prawns, Nile sardines and Nile perch. Use information from to state which of these is the least energy efficient for humans to eat and explain why. Suggest the effects on this ecosystem of increasing the mass of Nile tilapia taken from the lake by human fishing. Suggest and explain ways in which the fish populations of the Lake Victoria ecosystem can be managed so that they provide a sustainable resource. shows a diagram of the Nile perch gas exchange system and part of the circulatory system. heart key direction of blood flow gills Describe the similarities and differences between the human and Nile perch circulatory and respiratory systems. similarities differences
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THEORY
2024
Paper 2, Variant 1
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Questions Discovered
49