DP Biology Questionbank

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.

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.

Discuss the need for international cooperation to solve the problems of declining coral populations.

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

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

Calculate the total number of M. lucifugus flights that were recorded in the summer of 2007

Suggest one limitation of this recording method in determining the accurate mean number of individual bats flying.

Calculate the percentage decline in the mean number of M. lucifugus flights for 2009 when compared to 2008.

Evaluate the conclusion that the decline in the population of M. lucifugus is due to infection by the fungus.

Distinguish between the patterns of hibernation of the uninfected and infected bats.

Based on the data and your biological knowledge, suggest how the infection could lead to premature death in a bat.

Outline the relationship between date of death and the mean interval between hibernation emergence periods.

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.

Suggest one reason, other than the interval between hibernation emergence periods, for some infected bats surviving longer than others.

Using all of the data, predict the effect of WNS on bat populations.

Outline how chi-squared can be used to test for an association between the distributions of the two species.

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.

The Venus flytrap (Dionaea muscipula) is a photosynthetic plant. It obtains nitrogen but not energy by digesting captured insects.

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

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

Describe how detritivores obtain nutrition and the effects they have in ecosystems.

Compare and contrast the trends for O. rufipogon and O. sativa indica.

Compare and contrast the design of both mesocosms (vertical flow and horizontal flow).

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

State the distance from the city centre at which the highest proportion of plants sampled contained HCN.

Outline the relationship shown in the graph.

Deduce whether the pattern of cyanogenesis was the same in all of the areas around all four cities.

Discuss whether the data supports the hypothesis that the gradient in cyanogenesis is due to its benefits against herbivory in rural areas.

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.

Outline the criteria that should be used to assess whether a group of organisms is a species.

Using the data, outline the different use of thiamethoxam in North and South America.

Identify the total percentage of honey samples contaminated with neonicotinoid pesticides in the continent with the lowest overall levels of contamination.

. . . . . . . . . . . . %

Deduce the conclusions that can be drawn from the data in the graph.

Suggest a reason for the effect of a diet reduced in acetylcholine on the larval survival rate.

Compare and contrast the effect of clothianidin and thiacloprid treatments on the concentration of acetylcholine in royal jelly.

Describe the effect of temperature on the total biomass.

Explain the effect of temperature on the rate of photosynthesis in this mesocosm.

Suggest two abiotic factors, other than temperature and nutrient supply, that may affect the production of biomass of the grasslands.

The trout, Oncorhynchus mykiss, that live in West Brush Creek and Cement Creek also feed on the mayflies. Fishermen come to Colorado to catch and eat trout. Draw a diagram of part of a food web for the creeks in Colorado, including mayflies, humans, trout and bats.

Explain the processes by which energy enters and flows through ecosystems.

Draw a labelled diagram of a pyramid of energy.

Describe how energy flows through and is used by organisms in ecosystems.

Explain the role of decomposers in an ecosystem.

The diagram shows the food web for an aquatic ecosystem in which letters R–Z represent individual species.

[Source: © International Baccalaureate Organization 2019]

Which organism is a tertiary consumer?

A. Organism T

B. Organism U

C. Organism W

D. Organism Y

The diagram shows the food web for an aquatic ecosystem in which letters R–Z represent individual species.

[Source: © International Baccalaureate Organization 2019]

Which organism is a tertiary consumer?

A. Organism T

B. Organism U

C. Organism W

D. Organism Y

The Silver Springs feed into the Silver River in Florida. The diagram shows a pyramid of energy for the Silver Springs ecosystem. The units are kJ m^–2 y^–1.

[Source: © International Baccalaureate Organization 2019]

What do level I and level III represent in the pyramid of energy?

State two causes of the decrease of biomass along food chains in terrestrial ecosystems.

Explain the movement of energy and inorganic nutrients in an ecosystem.

Distinguish between the transfers of energy and inorganic nutrients in ecosystems.

Outline the criteria that should be used to assess whether a group of organisms is a species.

Explain how energy enters, flows through and is lost from marine food chains.

Deduce whether jellyfish or crustacea are a richer source of carbon in a food chain.

Suggest with a reason whether having a large body mass is an advantage or disadvantage for jellyfish.

The diagram shows the flow of energy through an ecosystem in ${\text{kJ\hspace{0.05em}m}}^{–2}{\text{\hspace{0.05em}y}}^{–1}.$

The image shows an example of a soil food web.

[Source: Anon., n.d. The Soil Food Web. [image online] Available at: https://www.nrcs.usda.gov/wps/portal/nrcs/
photogallery/soils/health/biology/gallery/?cid=1788&position=Promo [Accessed 11 March 2020].]

Draw a food chain from this food web, showing at least three organisms.

Explain the reasons for food chains rarely containing more than four or five trophic levels.

Compare and contrast the effects of temperature on the biomass of autotrophs and heterotrophs with added nutrients.

Suggest reasons for the decreases in biomass of autotrophs as temperature rises, despite the increases in photosynthesis.

Outline energy flow through a community in a natural ecosystem.

Outline the trends shown in the data in the graph.

Suggest reasons for the differences in the numbers of oysters drilled, as shown in the bar charts.

The radula in a gastropod is hard but not made of calcium carbonate. Outline how this statement is supported by the drilling success of the gastropods in seawater with normal or high CO₂ concentrations.

The diagram shows the carbon cycle.

[Source: © International Baccalaureate Organization 2017]

Which two processes correspond to the labelled arrows?

A. K is combustion and L is catabolism.

B. J is anabolism and K is respiration.

C. J is combustion and K is respiration.

D. J is anabolism and L is catabolism.

Describe the process of peat formation.

The structure of organisms is based on organic molecules containing carbon. Explain the cycling of carbon in an ecosystem.

The table shows the global carbon budget over two decades; the years 1990 to 1999 and 2000 to 2009.

[Source: © International Baccalaureate Organization 2019]

Using the table, explain causes of the changes in carbon flux over the two decades.

Calculate the percentage increase in the use of liquid fuels from 1950 to 1975.

%

Referring to the data, compare and contrast the changes in the use of the different fuels between 1950 and 1975.

In the diagram, which of the processes labelled A to D transfers the largest mass of carbon per year in a woodland ecosystem?

[Source: © International Baccalaureate Organization 2019]

Explain the transformations of carbon compounds in the carbon cycle.

Outline the role of methanogenic archaeans in the movement of carbon in ecosystems.

Describe how autotrophs absorb light energy

State one process that results in the loss of carbon dioxide from a marine organism such as a crustacean or a jellyfish.

The crustacean and the jellyfish obtain carbon compounds by feeding. State one source of carbon for marine organisms, other than feeding.

The diagram shows the carbon flux in gigatonnes per year between some of the Earth’s global reservoirs.

[Source: Figure 7.3 and Table 7.1 from Denman, K.L., G. Brasseur, A. Chidthaisong, P. Ciais, P.M. Cox, R.E. Dickinson, D.
Hauglustaine, C. Heinze, E. Holland, D. Jacob, U. Lohmann, S Ramachandran, P.L. da Silva Dias, S.C. Wofsy and
X. Zhang, 2007: Couplings Between Changes in the Climate System and Biogeochemistry. In: Climate Change
2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the
Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt,
M. Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.]

What can be deduced from the information in the diagram?

A. Arrows S are mainly due to respiration of marine plants and animals.

B. Photosynthesis is a component of both arrows Q and S.

C. Every day, more carbon is removed from the ocean than is added.

D. Ocean carbon is stored as dissolved calcium carbonate.

Calculate the difference in coral cover in 1996 and 2002. No working required.

Describe the evidence that the ocean temperature has an effect on coral cover.

Comment on whether the experimental data supports the observed data from the ocean.

(i) Describe the trend in calcification when the pH is decreased at 25 –26°C.

(ii) In environmental studies, a critical value is the level at which a population declines or shows signs of poor health. Suggest a critical pH for P. onkodes.

(iii) Using all of the data, comment on the hypothesis that ocean acidification in warming seas will have the same effect on all species of coral.

Outline causes of ocean acidification.

Outline reasons for the change occurring at Z. 

The short-tailed albatross (Phoebastria albatrus) nests and breeds on remote low-lying coral islands in the Pacific Ocean. Predict how global warming may threaten the survival of such an ocean bird.

Outline how greenhouse gases interact with radiation and contribute to global warming.

Deforestation and agricultural activities including the production of crops and livestock are thought to play a major role in the greenhouse effect. The graph shows annual trends in rates of deforestation and the production of soybeans and cattle in the state of Mato Grosso in Brazil in the period from 2001 to 2010.

[Source: 'Decoupling of deforestation and soy production in the southern Amazon during the late 2000s.'
Marcia N. Macedo, Ruth S. DeFries, Douglas C. Morton, Claudia M. Stickler, Gillian L. Galford, and Yosio E.
Shimabukuro PNAS January 24, 2012, 109 (4) 1341–1346; https://doi.org/10.1073/pnas.1111374109,
used with permission]

What conclusion can be drawn from the information in this graph?

A. The decline in rates of deforestation led to an increase in production of CO2.

B. Soybean production accounted for a greater proportion of deforestation than cattle production.

C. Forest habitats declined during the first few years of the study.

D. The decline in rates of deforestation is due to an increase in soybean production.

Discuss the relationship between atmospheric carbon dioxide concentration and global temperatures.

The graph shows atmospheric oxygen levels over time.

About 2.5 billion years ago, a significant rise in atmospheric oxygen occurred. What was the cause of this rise?

A. Photosynthesis by non-vascular land plants

B. Photosynthesis by vascular land plants

C. Oxygen produced by photosynthetic bacteria being released from the ocean into the atmosphere

D. Volcanic activity

The map shows the widespread distribution of coral reef ecosystems (indicated by black dots) in the world’s oceans. Death of coral reefs is related to increasing atmospheric carbon dioxide concentrations.

[Source: National Oceanic and Atmospheric Administration, 2021. Where Reef Building Corals Found. [map online] Available at: https://oceanservice.noaa.gov/education/tutorial_corals/media/supp_coral05a.html [Accessed 20 May 2021].]

Explain how increased atmospheric carbon dioxide concentrations can lead to coral death.

Which gases have made the most significant contributions to global warming?

A. Water and carbon dioxide

B. Carbon dioxide and methane

C. Methane and nitrous oxide

D. Carbon dioxide and ozone

Describe the evidence that is provided by the data in the table for the harmful effects of rising sea temperatures on corals.

The researchers concluded that there was a threshold coral cover percentage, below which infection rates tended to remain fairly low. Using the data in the table, identify this threshold level.

Suggest a reason for a larger percentage of corals being infected with white syndrome on reefs with a higher cover of corals.

Compare and contrast the data for 1998–1999 and 2002–2003.

Some scientists predict that, if humans continue to produce carbon dioxide at the current rate, the pH of the oceans will become more acidic. Suggest possible effects on the coral reefs.

Calculate the increase in mean global temperature between 1880 and 2010.

.......... °C

Explain how increased carbon dioxide in the air leads to the greenhouse effect.