Energy & Feeding Relationships

9.The diagram shows a woodland food web. Which statement is correct?

10.In a food chain, energy is transferred from the Sun to a producer, and then from one organism to the next when it is eaten. Which form of energy is transferred (a) from the Sun to a producer, and (b) from one organism to another when it is eaten?

11.Which of the following processes is carried out by bacteria in the roots of leguminous plants?

12.In a food chain, only about 10% of the energy stored at one trophic level is transferred to the next. If the producers in a grassland ecosystem store 50,000 kJ of energy, how much energy is available to the secondary consumers?

13.The table shows data from a food chain. What is the percentage of biomass transferred from the aphids to the predatory midges? Organism | Number | Total biomass (kg) --- | --- | --- Oak tree | 1 | 400,000 Aphids | 9,000 | 900 Predatory midges | 120 | 45

14.A scientist grows bacterial cells under ideal conditions. Each cell reproduces once every 30 minutes. Starting with 10 cells, and assuming 10% die at the end of the growth period, how many cells are present after 8 hours?

15.In the carbon cycle, which process removes carbon dioxide from the atmosphere?

16.The diagram shows a pyramid of energy. Which trophic level has the greatest energy loss to the environment?

17.The graph shows a sigmoid population growth curve. During which phase is the birth rate equal to the death rate?

18.In a food web, if all the chaffinches die, which effect is most likely?

19.Which statement about pyramids of biomass is correct?

20.What is the principal source of energy input to biological systems?

21.The diagram shows part of the nitrogen cycle. Which process is carried out by bacteria in the root nodules of leguminous plants?

22.A food chain is: phytoplankton → zooplankton → small fish → large fish. The biomass of phytoplankton is 10,000 kg. If only 10% of energy is transferred at each trophic level, what is the biomass of large fish?

23.Which of the following is an example of a population?

24.A student investigates energy loss in a food chain. The producer (grass) contains 20,000 kJ of energy. The primary consumer (rabbit) gains 2,000 kJ. What percentage of energy is transferred from the producer to the primary consumer?

25.In an experiment, the dry mass of organisms at each trophic level in a grassland food chain is measured. The producer has 500 g/m², primary consumer 50 g/m², secondary consumer 5 g/m². What is the efficiency of biomass transfer from primary to secondary consumer?

26.A food web contains: grass → rabbit → fox. If a disease kills all the rabbits, what is the most likely effect on the grass population?

27.Which of the following is a correct definition of a community?

28.The diagram shows a pyramid of biomass for a food chain: grass → insects → lizards. Which statement is correct?

29.In the nitrogen cycle, which process converts ammonium compounds into nitrates?

30.A population of bacteria is grown in a closed culture. After 2 hours, the population enters the log phase. Which factor is most likely to cause the population to enter the stationary phase?

31.In a food chain, 10,000 kJ of energy is available at the producer level. Only 10% is transferred to each successive trophic level. How much energy is available at the tertiary consumer level?

32.Which of the following is a producer in a food chain?

33.The diagram shows a food web: oak tree → caterpillar → blue tit → sparrowhawk. Which organism is a secondary consumer?

34.A student sets up an experiment to measure the rate of decomposition of dead leaves by microorganisms. Which condition would speed up decomposition?

35.Which process in the carbon cycle returns carbon dioxide to the atmosphere?

36.Which of the following is the principal source of energy input to biological systems?

37.What is a community?

38.The diagram shows a pyramid of biomass for a food chain. Which statement about pyramids of biomass is correct?

39.Only about 10% of the energy stored at each trophic level is available to the next trophic level. Which of the following is NOT a reason for this energy loss?

40.A pyramid of biomass is always pyramid-shaped.

41.Which of the following is the correct definition of a community?

42.In the carbon cycle, which process returns carbon dioxide to the atmosphere?

43.Pyramids of numbers can sometimes be inverted (wider at the top than the bottom).

44.Only about 10% of energy stored at each trophic level is available to the next. Which of the following is NOT a reason for this energy loss?

45.Which of the following processes converts ammonium compounds into nitrates in the nitrogen cycle?

46.In a sigmoid population growth curve, the stationary phase occurs when the birth rate is less than the death rate.

47.Which of the following statements about the nitrogen cycle is correct?

48.Match each process in the carbon cycle with its correct description.

49.Arrange the following phases of a sigmoid population growth curve in the correct order starting from the beginning of growth.

50.Complete the sentence using the correct word.

51.In a food chain, 10,000 kJ of energy is available at the producer level. Only 10% is transferred to each successive trophic level. How much energy (in kJ) is available to the secondary consumers?

52.In a food chain, the producers contain 50,000 kJ of energy. If only 10% of energy is transferred to each successive trophic level, how much energy (in kJ) is available to the tertiary consumers?

53.Complete the sentence about the nitrogen cycle.

54.In a food chain, 10,000 kJ of energy is available at the producer level. Only 10% is transferred to each successive trophic level. How much energy (in kJ) is available to the secondary consumers?

55.In a food chain, the producers contain 50,000 kJ of energy. If only 10% of energy is transferred to each successive trophic level, how much energy (in kJ) is available to the tertiary consumers?