Organisms and their environment — IGCSE Biology (0970) questions by topic

The diagram shows a food web in a freshwater habitat. Alga (a producer) is fed on by stonefly larva, blackfly larva and mayfly larva. These larvae are eaten by diving beetle,…

The graphs show the number of herbivores in a habitat over a period of time. At time X, the carnivores are removed from the habitat. Graph A shows the number of herbivores staying…

Some statements about food production are listed. 1 Agricultural machinery allows the efficient use of larger areas of land. 2 Herbicides increase the competition of crop plants…

What is the principal source of energy input to biological systems? A kinetic B photosynthesis C respiration D the Sun

The diagram shows the flow of energy in a food chain as four boxes labelled organism A, organism B, organism C and organism D connected by arrows. Energy flows from organism C up…

The diagram shows part of the carbon cycle. Boxes show 'carbon dioxide in atmosphere', 'plants', 'animals', and 'waste products and dead organisms'. Numbered arrows: arrow 1 goes…

The graph shows the percentage of species lost, in three different animal groups (mammals; reptiles and amphibians; birds), due to different human activities during the last ten…

Which statement about a pyramid of energy for a food chain is correct? A It shows how energy is lost at each trophic level. B It shows the energy stored at each trophic level. C…

The food web shows part of an ocean ecosystem. The producers are kelp, algae and diatom. The food web links: kelp → sea urchin; algae → mussel and clam; diatom → prawn; sea…

A student investigated the effect of high temperature on the production of nitrate ions in soil. Two samples of soil were taken. One sample was heated to 100 °C. All the nitrate…

Which letter represents the lag phase in the population graph shown? The graph plots number of individuals in the population (y-axis) against time (x-axis) as an S-shaped…

Which source of pollution can cause eutrophication? A carbon dioxide B methane C non-biodegradable plastic D sewage

Which row describes the energy flow into and through a food chain that starts with a plant? energy entering a food chain energy transferred between organisms in a food chain ---…

The diagram shows part of the nitrogen cycle. 'organic material' leads to 'ammonium ions'; 'ammonium ions' leads via process X to 'nitrate ions'; 'nitrate ions' leads to 'nitrogen…

Some pollution in oceans is caused by discarded plastics. Macroplastics are 0.5 cm and greater in diameter. Microplastics are smaller than 0.5 cm in diameter. State the smallest…

Fig. 1.1 shows a pyramid of energy for an ecosystem. The energy values (in J) for each trophic level are: trophic level 1 = 11212, trophic level 2 = 9804, trophic level 3 = 822,…

Some of the processes involved in the carbon cycle are listed. 1 combustion 2 decomposition 3 photosynthesis 4 respiration During the carbon cycle, which processes release carbon…

What are the effects of sewage pollution on the biodiversity and the number of bacteria in a river? Columns: biodiversity; number of bacteria. A decreases; decreases B decreases;…

The increase of which gases contributes to an enhanced greenhouse effect? A carbon dioxide and methane B methane and nitrogen C nitrogen and oxygen D oxygen and carbon dioxide

The diagram shows a food chain: plant leaf → slug → frog → fox. Which terms describe the position of the fox in this food chain? Columns: consumer; trophic level. A quaternary;…

These are processes found in the carbon cycle: • combustion • decomposition • feeding • photosynthesis • respiration How many of these processes release carbon dioxide into the…

Which change occurs when areas of forest are cleared for farming? A decreased release of carbon dioxide into the atmosphere B increased biodiversity C increased loss of soil D…

What is the main source of energy input to biological systems? A glucose B oxygen C plants D the Sun

Which organisms remove nitrate ions from soil? A denitrifying bacteria and nitrogen-fixing bacteria in root nodules B denitrifying bacteria and plants C nitrifying bacteria and…

What are two reasons for organisms becoming endangered? 1 habitat destruction 2 monitoring 3 education 4 pollution 5 captive breeding programmes A 1 and 4 B 1 and 5 C 2 and 3 D 3…

Diagrams A–D show parts of the nitrogen cycle, each showing nitrogen gas in atmosphere, nitrogen fixation, denitrification and nitrates with arrows in different directions. Which…

What is an advantage of growing crops as a large-scale monoculture? A Biodiversity is increased. B Genetic variation is increased. C Water use is increased. D Yield of the crop is…

Cabbages are crop plants. Fig. 6.1 shows an area where the forest has been removed to create space for a monoculture of cabbage plants. Describe reasons for habitat destruction,…

Fig. 7.1 is a flowchart showing the stages of eutrophication. Complete Fig. 7.1. fertilisers enter a lake → the concentration of ............ increases → the growth of…

Which diagram shows a pyramid of biomass for the food chain shown? tree → caterpillar → bird Diagram A: large base (tree), medium middle (caterpillar), small top (bird) — correct…

Which statement about conservation is correct?

The diagram shows the amount of energy in kJ m⁻² yr⁻¹ at each trophic level of a food chain. producers (88 000) → primary consumers (14 000) → secondary consumers (2000)…

Which process in the nitrogen cycle removes nitrogen gas from the atmosphere?

What is a population?

A farmer has a small pond on their farm land. One year, most of the organisms in the pond die. The next year, the farmer decreases their use of nitrate fertilisers and fewer…

The graph shows how the population of a species of bird has increased following a conservation programme. Bar chart from 1990–2004: 1994≈40, 1996≈50, 1998≈105, 2000≈160, 2002≈230,…

Fig. 3.1 is a diagram of part of the carbon cycle showing: carbon in the atmosphere at top; carbon in plants on the left with arrow Q going up (to atmosphere) and arrow S going…

The flow chart in Fig. 6.1 shows one pathway of nitrogen as it travels through the nitrogen cycle. Complete the flow chart in Fig. 6.1: nitrogen in the atmosphere → nitrogen…

The diagram shows energy flow from the Sun, through a food chain (plant → animal → animal) and into the environment, with numbered arrows 1 (Sun to plant) and 2 (plant to animal).…

In a pyramid of numbers, what does the top of the pyramid represent? A carnivores B decomposers C herbivores D Sun

A few yeast cells were placed in a container of nutrient solution. The graph shows how their population size changed over time with four numbered phases. Which row shows when the…

The bloodworm is an organism found in heavily polluted water. The diagram shows where raw sewage flows into a river with positions A, B, C and D along the direction of flow. Where…

Which term is used to describe an organism that makes its own organic nutrients? A carnivore B decomposer C herbivore D producer

What is the principal source of energy for most food chains? A carbon dioxide gas B glucose C oxygen D sunlight

A single tree is food for a large population of caterpillars. Several small birds eat the caterpillars. The small birds are eaten by a bird of prey. Pyramids A–D show different…

The diagram shows the results of a survey on the types of animals found along a stretch of river near to a factory emptying pollutants into the water, with different indicator…

The diagram shows energy flow from the Sun, through a food chain (plant → animal → animal) and into the environment, with numbered arrows for stage 1 (Sun to plant) and stage 2…

A few yeast cells were placed in a container of nutrient solution. The graph shows how their population size changed over time with four numbered phases. Which row shows when the…

The number of Atlantic bluefin tuna fish found in the Atlantic Ocean has significantly decreased in the last 50 years. Which method would make the biggest improvement in the…

The bloodworm is an organism found in heavily polluted water. The diagram shows where raw sewage flows into a river with positions A, B, C and D along the direction of flow. Where…

Which term is used to describe an organism that makes its own organic nutrients? A carnivore B decomposer C herbivore D producer

The diagram shows two pyramids (P and Q) based on food chains in which the producer is a large tree. What do the two pyramids represent? Columns: P; Q. A biomass; biomass B…

What is a negative impact on the environment caused by deforestation? A decrease in land for livestock production B decreased levels of carbon dioxide in the air C increase in…

The diagram shows the positions of four farms (A, B, C, D) and the concentrations of nitrate at different points in a river, with the direction of flow indicated. Which farm is…

Fig. 5.1 shows a pyramid of numbers for a food chain: snake (2 organisms), tree frog (10), banana weevil (60), banana plant (1). Write the food chain for the pyramid of numbers…

Fig. 6.1 is a graph that shows the concentration of dissolved oxygen in the water at increasing distances along a river. Untreated sewage is released into the river (marked on the…

A student recorded information about an aquatic habitat. Fig. 4.1 shows the student's notes: Aquatic plants provide food for freshwater shrimps and midges. Mayflies also feed on…

A food chain is shown: lettuce plant → slug → hedgehog. By which process is energy transferred from the lettuce plant to the slug? A egestion B excretion C ingestion D respiration

A single bush is food for a large population of greenfly. Several ladybirds eat the greenfly. The ladybirds are eaten by a bird. Pyramids A–D show different shapes. Which diagram…

The diagram shows the flow of energy in an ecosystem: Sun → producer → box 1 → box 2, with respiration losses and death leading to box 3. Which row correctly completes boxes 1, 2…

The diagram shows a food chain: tree → insect → blue tit → hawk. Which statement about a pyramid based on this food chain is correct? A Drawn as a pyramid of biomass, the hawk…

During the nitrogen cycle, which process releases nitrogen gas into the air? A decomposition B denitrification C nitrification D nitrogen fixation

One method of conserving fish stocks is to have a minimum mesh size for fishing nets. How is the mesh size chosen to conserve a particular fish species? A The holes in the net…

Fig. 4.1 shows a marine food web (algae, phytoplankton, limpet, mussel, zooplankton, octopus, shark, sardine). Place ticks (✓) in the boxes to show the correct descriptions for…