IB Biology Ecosystems Part C Exam 2024
Which of the following are all abiotic components of an ecosystem?
A. Dirt, water and algae
B. Bacteria, sand and rock
C. Water, Sun and fungus
D.Water, dirt and rock
Which of the following terms encompasses all the others?
A. Heterotrophs
B. Herbivores
C. Carnivores
D. Primary consumers
Which is the proper order from smallest to largest of the hierarchy of life?
A. organism-population-species-community-ecosystem-biomes-biosphere
B. species-population-organism-community-ecosystem-biomes-biosphere
C. organism-species-population-community-ecosystem-biomes-biosphere
D. organism-population-species-community-ecosystem-biosphere-biomes
How can a chi-squared test be used in ecological research?
A. To test the effect of an abiotic factor on one plant species
B) To test whether two species tend to live together
C. To test whether one population of plants is taller than another
D. To test whether one species is more tolerant to heavy metals than another
How is energy passed from one trophic level to the next?
I. Food
II. Light
III. Heat
A. I only
B. I and II only
C. II and IlI only
D. I, Il and II I
Which is a density-independent factor for a kangaroo?
A. Forest fire
B. Predation
C. Overproduction of offspring
D. Spread of disease
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
What restricts the length of a food chain?
A. Energy losses between the trophic levels
B. A greater biomass at the higher trophic levels
C. The number of species in the food web
D. The size of the individual organism
In a pond, two species of fish feed on insects and worms. The insects feed
on the different green plants that live in the water. What constitutes a population
in this ecosystem?
A. All the living organisms
B. All the animals
C. All the fish
D. All the fish of one species
Which of the following statements is correct?
A. Capture-Mark-Release-Recapture can be used to estimate the population of
sessile organisms
B. A chi-square test of association will determine whether two species have a
positive or negative association
C. Nitrogen fixing bacteria have a mutualistic relationship with plants
D. Density-independent factors have more of an impact on a higher population
Density
Which of the following are required for the sustainability of an
Ecosystem?
I. Availability of energy
II. Detoxification of waste
III. Quaternary consumers
IV. Nutrient cycling
A. I and Il only
B. I, II, and III only
C. I, II, and IV only
D. I, II, III and IV
The diagram shows the energy flow between five "sinks" in a terrestrial ecosystem
In a typical terrestrial ecosystem, which trophic level would have the highest biomass?
A. Autotrophs
B. Primary consumers
C. Secondary consumers
D. Detritus feeders
Black walnut (Juglans nigra) secretes the chemical juglone into the soil
surrounding its roots. Juglone inhibits cell respiration in other species of plants.
What does this example illustrate?
A. Mutualism
B. Intraspecific competition
C. Allelopathy
D. Parasitism
Over time, the hull of a sunken ship may become colonized by a wide
range of marine organisms. What term is used to describe all of the organisms
living in and on a sunken ship?
A. A community
B. An ecological niche
C. A population
D. An ecosystem
What is a difference between detritivores and saprotrophs?
16. Which statement applies to transfers in an ecosystem?
A. Green plants can transfer heat energy from the sun into chemical energy.
B. The greatest loss of energy occurs towards the end of a food chain.
C. Production of carbon dioxide by respiration results in loss of biomass in a
food chain.
D. Both energy and nutrients are finite and must be recycled.
17. At each trophic level, energy is lost. How is this energy regained by the
ecosystem?
A. Heat
B. Photosynthesis
C. Recycling
D. Death of consumers
18. Animals in the highest trophic level of a food chain will often be the
largest in body size but will be few in numbers. What accounts for the small
numbers?
A. Food eaten by animals at the highest trophic level has a lower energy content
per gram
B. Energy losses through the food chain
C. Conversion of heat energy into chemical energy
D. Biomass of producers is small
19. Which processes occur in an ecosystem?
I. Biomass increases in each successive trophic level.
II. Inorganic nutrients are recycled.
III. Chemical energy is stored in carbon compounds.
A. I and II only
B. I and III only
C. II and III only
D. I, II and III
20. Which organism would be classified as a saprotroph?
A. A single-celled eukaryote that obtains its carbon compounds by digestion photosynthesis and ingestion of other single-celled organisms
B. A jellyfish that uses the stinging cells in its tentacles to paralyze its prey, which is passed to an internal gastric cavity through a single opening
C. A fungus that feeds by secretion of digestive enzymes onto its food and absorption of digested material
D. A dung beetle that feeds on the fecal material left behind by other animals
21. What is lost between trophic levels in ecosystems and cannot be recycled?
A. Heat
B. Nitrogen
C. Carbon compounds
D. Biomass
22. 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
23. Which level(s) of ecological complexity involves) biotic factors but not abiotic factors?
I. Community Organism
II. Ecosystem species
III. Population
A. I only
B. II only
C. I and II only
D. I and III only
24. The following diagram shows part of food web from Yellowstone Park
What would be the short-term effects on the populations of the other species if
the gray wolf were exterminated?
25. What are the effects of limiting factors?
A. They separate biotic factors from abiotic factors
B. They determine which animal is the predator and which one is the prey.
C. They regulate how many organisms live an ecosystem.
D. They determine which natural disasters will hit an area
26. What happens to the population of a species after it reaches it's carrying capacity?
A. It will increase linearly over time
B. It will remain relatively the same over time
C. It will decrease slowly over time
D. It will drop quickly in numbers due to lack of resources
27. Which human activity can change the carrying capacity of a population?
A. Studying the habitats of a particular species
B. Compiling a list of habitats in an ecosystem
C. Manipulating resources in an ecosystem
D. Using the random quadrat method to estimate the population size of a
species.
28. The pyramid of energy shows the annual gross productivity for each trophic level in the Silver Springs ecosystem in Florida.
What does the energy pyramid show?
A. Most energy is lost by the autotrophs
B. There are a larger number of herbivores than carnivores
C. The biggest loss of energy is when sunlight reflects from plants
D. The energy in the trophic levels is affected by seasonal changes
29. Which of the following interspecific relationships is not harmful to one of the organisms?
A. A pathogen invading a host
B. A carnivore ingesting its prey
C. A honeybee interacting with a flower
D. A herbivore grazing on the grass
30. The amount of rain in a temperate grassland can dictate the population fluxes in various trophic levels of the food web. This is an example of what?
A. Top-down control
B. Allelopathy
C. Pathogenicity
D. Bottom-up control
ANSWER KEY:
D
A
C
B
A
A
C
A
D
C
C
A
C
A
C
C
B
B
C
C
A
C
D
D
C
B
C
A
C
D