Date | November 2021 | Marks available | 1 | Reference code | 21N.1.SL.TZ0.17 |
Level | Standard level | Paper | Paper 1 | Time zone | TZ0 / no time zone |
Command term | Question number | 17 | Adapted from | N/A |
Question
What is exchanged between a sealed mesocosm and the surrounding external environment?
A. Energy
B. Water
C. Air
D. Nothing can pass
Markscheme
A
Examiners report
This question had the lowest discrimination index on the paper so some well-prepared candidates must have answered it incorrectly. More than half of candidates thought that nothing can pass in or out of a sealed mesocosm, forgetting that energy will almost certainly be able to pass in or out in the form of heat and probably also in as light. In terms of thermodynamics, a closed system exchanges energy but not matter with its environment.
Syllabus sections
- 19N.1.SL.TZ0.18: What is the ecological term for a group of different types of organisms that live together...
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21M.2.SL.TZ2.1d:
Deduce the conclusions that can be drawn from the data in the graph.
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20N.2.HL.TZ0.1a.ii:
Outline the relationship shown in the graph.
- 21M.1.SL.TZ2.17: Which organism would be classified as a saprotroph? A. A single-celled eukaryote that...
- 17M.2.HL.TZ2.4a.ii: Using the food web, identify a saprotroph.
- 16N.2.SL.TZ0.1d: Analyse the data to find the effect of flooding and tree felling by beavers on the activity...
- 19M.1.SL.TZ2.19: Which is not essential in a viable mesocosm? A. Light source B. Autotroph C....
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18M.2.HL.TZ1.1a:
Calculate the total number of M. lucifugus flights that were recorded in the summer of 2007
- 16N.2.SL.TZ0.1b: Describe the effect dams have on water temperature.
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18N.1.SL.TZ0.18:
The Australian pitcher plant (Cephalotus follicularis) is a green plant that traps and feeds on flies and other live insects. What is this plant’s mode of nutrition?
A. Producer and saprotroph
B. Autotroph and detritivore
C. Autotroph and heterotroph
D. Consumer and saprotroph
- 17M.1.HL.TZ2.22: The image shows a transect through a stream and a field. Which calculation would test for...
- 22M.1.SL.TZ1.17: What is a community? A. A group of individuals of the same species in a given area B. A...
- 18N.1.SL.TZ0.24: Limpets are molluscs with conical shells that cling tightly to rocks on seashores. In a study...
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18M.2.HL.TZ1.1b:
Suggest one limitation of this recording method in determining the accurate mean number of individual bats flying.
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18M.2.HL.TZ1.1c.i:
Calculate the percentage decline in the mean number of M. lucifugus flights for 2009 when compared to 2008.
- 16N.2.SL.TZ0.4c: Discuss whether or not horses and donkeys should be placed in the same species.
- 21M.2.SL.TZ2.1a: Identify in which continent the fewest types of neonicotinoid were detected in honey samples.
- 19N.2.SL.TZ0.4a: State the immediate consequence of a species producing more offspring than the environment...
- 21N.2.SL.TZ0.3a: Compare and contrast the mode of nutrition of detritivores and saprotrophs.
- 18M.1.HL.TZ2.22: Which processes occur in an ecosystem? I. Biomass increases in each successive trophic...
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16N.2.SL.TZ0.1g:
The North American beaver (Castor canadensis) was introduced to islands adjacent to Argentina and Chile where they have become an invasive species. Discuss one ecological criterion (a basis for deciding) whether beavers are harmful or helpful to the ecosystems there.
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21M.2.SL.TZ2.1c:
Identify the total percentage of honey samples contaminated with neonicotinoid pesticides in the continent with the lowest overall levels of contamination.
. . . . . . . . . . . . %
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16N.2.SL.TZ0.1c:
The graph shows the mean dry mass of mayflies relative to the water temperature in their habitats.
Using the graph, discuss evidence for the hypothesis that mayflies grow to greater dry mass in cooler water.
- 19M.3.SL.TZ1.2b: Outline the role of fungi in nutrient cycling.
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17N.1.SL.TZ0.17:
In an area of forest measuring 100 m by 100 m, samples were taken to estimate the number of silver maple (Acer saccharinum) trees in the forest. The number of trees counted in each of five areas of 400 m2 was recorded.
Approximately how many silver maple trees are in the 10000m2 area of forest?
A. 5
B. 25
C. 125
D. 625
- 21N.2.HL.TZ0.1g: The first study used mesocosms and the second study was carried out in natural grassland....
- 17M.2.HL.TZ2.4a.i: Using the food web, identify a detritivore.
- 21N.2.HL.TZ0.5a: Compare and contrast the mode of nutrition of detritivores and saprotrophs.
- 17M.1.SL.TZ2.27: The bacterium Neisseria gonorrhoeae causes infections related to the human reproductive...
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18M.1.SL.TZ2.17:
The image shows a food web.
[Source: Adapted from Thompsma/Wikipedia]
Which organism in the food web is assigned to its method of nutrition?
A. A violet webcap fungus is both an autotroph and a heterotroph.
B. A pillbug is a secondary consumer.
C. Bacteria are saprotrophs.
D. A violet webcap fungus is a detritivore.
- 16N.1.SL.TZ0.17: What is the classification of an organism that is able to make organic compounds from...
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18M.1.HL.TZ1.14:
The three-toed sloth, Bradypus variegatus, lives in tree tops where it feeds on leaves. It also feeds on algae and fungi which live in its fur.
[Source: Image from https://commons.wikimedia.org/wiki/File:Bradypus_variegatus.jpg. Christian Mehlführer.
Licensed under CC by 2.5 https://creativecommons.org/licenses/by/2.5/deed.en]In which trophic group should the three-toed sloth be classified?
A. Autotroph
B. Consumer
C. Detritivore
D. Saprotroph
- 19N.2.SL.TZ0.1b: Determine which type of rice has the lowest overall diversity index.
- 19N.2.SL.TZ0.1a: State the reason that O. sativa and O. rufipogon are classified as different species.
- 19N.1.HL.TZ0.14: Hummingbirds eat flower nectar and small insects. To which nutritional group do they...
- 17M.1.SL.TZ1.21: Cladograms can be created by comparing DNA or protein sequences. The cladogram on the left is...
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18M.2.HL.TZ1.1e:
Based on the data and your biological knowledge, suggest how the infection could lead to premature death in a bat.
- 17M.2.HL.TZ1.4b: Most of the surface of the Earth is covered with a wide diversity of ecosystems. Outline two...
- 20N.2.SL.TZ0.2b: Outline the method of nutrition carried out by P. caudatum.
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21M.2.SL.TZ2.1e:
Suggest a reason for the effect of a diet reduced in acetylcholine on the larval survival rate.
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21M.2.SL.TZ2.1f:
Compare and contrast the effect of clothianidin and thiacloprid treatments on the concentration of acetylcholine in royal jelly.
- 16N.2.SL.TZ0.1a: Calculate the difference in the mean dry mass of mayflies upstream and downstream of Cement...
- 21N.2.SL.TZ0.1e: This study was carried out over six years on the Australian Great Barrier Reef. State one...
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18M.1.SL.TZ2.18:
The Venus flytrap (Dionaea muscipula) is a photosynthetic plant. It obtains nitrogen but not energy by digesting captured insects.
[Source: adapted from www.flytrapcare.com]
Which term describes this plant?
A. Secondary consumer
B. Autotroph
C. Primary consumer
D. Saprotroph
- 18N.3.HL.TZ0.14d: Suggest advantages of undertaking this experiment in the sea rather than in the laboratory.
- 19M.2.HL.TZ1.7c: Outline the features of ecosystems that make them sustainable.
- 17M.3.HL.TZ1.3b: Mesocosm experiments using water from Narragansett Bay were completed in the laboratory...
- 20N.2.HL.TZ0.1d.i: Identify with a reason the city where the plants were more insulated from freezing temperatures.
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21N.2.HL.TZ0.1c:
Explain the effect of temperature on the rate of photosynthesis in this mesocosm.
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20N.2.HL.TZ0.1c:
Discuss whether the data supports the hypothesis that the gradient in cyanogenesis is due to its benefits against herbivory in rural areas.
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20N.1.SL.TZ0.16:
Which level(s) of ecological complexity involve(s) biotic factors but not abiotic factors?
I. Community
II. Ecosystem
III. Population
A. I only
B. II only
C. I and II only
D. I and III only
- 20N.1.SL.TZ0.17: How can a chi-squared test be used in ecological research? A. To test the effect of an...
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20N.2.HL.TZ0.1a.i:
State the distance from the city centre at which the highest proportion of plants sampled contained HCN.
- 18N.2.SL.TZ0.3c: An increase in global temperatures poses a critical threat to boreal forests. Explain the...
- 18N.2.HL.TZ0.8a: Extensive areas of the rainforest in Cambodia are being cleared for large-scale rubber...
- 18N.2.HL.TZ0.4c: An increase in global temperatures poses a critical threat to boreal forests. Explain the...
- 17M.2.HL.TZ1.1f.ii: Suggest a reason for the greater expression of the gene for the urea transporter after an...
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18N.1.SL.TZ0.19:
In 1789 Gilbert White, a naturalist, observed eight breeding pairs of swifts (Apus apus) in the English village of Selborne. On average, each pair of swifts produces two offspring per year. This would allow the population to rise to 1030 swifts over 200 years. A bird survey carried out in 1983 revealed only 12 breeding pairs in this village.
What could have prevented the numbers rising to 1030?
I. The number of nesting sites remained the same.
II. The food supply of the swifts remained constant.
III. Predatory birds in the area were exterminated.
A. I only
B. I and II only
C. II and III only
D. I, II and III
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21M.2.SL.TZ2.1b:
Using the data, outline the different use of thiamethoxam in North and South America.
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18M.3.SL.TZ2.2b:
Outline how chi-squared can be used to test for an association between the distributions of the two species.
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20N.2.HL.TZ0.1d.ii:
Using all of the data so far, suggest whether exposure to freezing temperatures in the four cities is supported as a reason for the differences in HCN production in T. repens.
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20N.2.HL.TZ0.1b:
Deduce whether the pattern of cyanogenesis was the same in all of the areas around all four cities.
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20N.2.HL.TZ0.8a:
Outline the criteria that should be used to assess whether a group of organisms is a species.
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18M.2.HL.TZ1.1f:
Outline the relationship between date of death and the mean interval between hibernation emergence periods.
- 18M.3.SL.TZ2.2a: Using the scale bar, determine the area of quadrat A1, giving the units.
- 17M.2.SL.TZ1.1c: Estimate how much smaller drilled oysters raised in seawater at a high CO2 concentration were...
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18M.2.HL.TZ1.1d:
Distinguish between the patterns of hibernation of the uninfected and infected bats.
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18M.2.HL.TZ1.1i:
Using all of the data, predict the effect of WNS on bat populations.
- 19M.1.SL.TZ1.17: Which organism can best be described as a saprotroph? A. A fungus that digests its food...
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19M.2.SL.TZ1.8a:
Describe how detritivores obtain nutrition and the effects they have in ecosystems.
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16N.2.HL.TZ0.1i:
Discuss the need for international cooperation to solve the problems of declining coral populations.
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21N.2.HL.TZ0.1f:
Suggest two abiotic factors, other than temperature and nutrient supply, that may affect the production of biomass of the grasslands.
- 19N.2.SL.TZ0.1g: Using all of the data, discuss whether there is evidence that the two sub-species of O....
- 19N.2.SL.TZ0.4b: Explain the consequence of overpopulation on the survival and reproduction of better adapted...
- 19N.2.SL.TZ0.5b: Outline the principles used by scientists to classify organisms.
- 19N.3.HL.TZ0.1b: Suggest with a reason which system best reproduces the conditions of the natural environment.
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18M.2.HL.TZ1.1h:
Suggest one reason, other than the interval between hibernation emergence periods, for some infected bats surviving longer than others.
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18M.2.HL.TZ1.1c.ii:
Evaluate the conclusion that the decline in the population of M. lucifugus is due to infection by the fungus.
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18M.2.HL.TZ1.1g:
Discuss whether the data in the graph show that there is a causal link between the date of death and the interval between hibernation emergence periods.
- 19N.3.HL.TZ0.1c: State two variables other than temperature and light that should be controlled in this...
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19N.2.SL.TZ0.1c:
Compare and contrast the trends for O. rufipogon and O. sativa indica.
- 21M.1.SL.TZ1.20: Over time, the hull of a sunken ship may become colonized by a wide range of marine...
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19N.3.HL.TZ0.1a:
Compare and contrast the design of both mesocosms (vertical flow and horizontal flow).
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21N.2.HL.TZ0.1a:
Describe the effect of temperature on the total biomass.
- 21N.2.HL.TZ0.1e: Describe the effects of temperature and nitrate concentration on biomass.