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ib biology 4.1 and 4.2 Questions and
Answers (Expert Solutions)
Q: Define the term species?, 🗹🗹: Organisms that reproduce together to produce
fertile offspring
Q: The following statements refer to a pyramid of energy.
I. Some material is not assimilated by each trophic level.
II. Energy transformations are never 100 % efficient.
III. Heat is lost during photosynthesis.
Which of the statements give the reason why a pyramid of energy is narrower at the top
than at the bottom?
A. I only
B. I and II only
C. II and III only
D. I, II and III, 🗹🗹: B. I and II only
Q: What is a population?, 🗹🗹: Organisms of a species living together in the same
area
Q: Which pair of statements is correct?
A. autotroph-obtains organic molecules from other organisms heterotroph-synthesizes
organic molecules from inorganic molecules
B. autotroph-synthesizes organic molecules from inorganic molecules
heterotroph-obtains organic molecules from other organisms
C. autotroph-synthesizes inorganic molecules from organic molecules
heterotroph-synthesizes organic molecules from inorganic molecules
D. autotroph-obtains inorganic molecules from other organisms
heterotroph-obtains inorganic molecules from other organisms, 🗹🗹: B. autotroph-
synthesizes organic molecules from inorganic molecules
heterotroph-obtains organic molecules from other organisms
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Q: What is an ecosystem?, 🗹🗹: A community and its abiotic environment
Q: What term can be used to describe clams that eat decaying plant matter?, 🗹🗹:
Detritivores
Q: At each trophic level energy is lost. How is this energy regained by the ecosystem?,
🗹🗹: Photosynthesis
Q: In ecosystems the amterm-6ount of energy that passes from one trophic level to the
next is called the conversion efficiency. What is the average conversion efficiency from
primary to secondary consumers in most ecosystems?, 🗹🗹: 10 %
Q: What is the mode of nutrition of midge larva?, 🗹🗹: Heterotroph
Q: Which represents a correct food chain from this web?
A. stickleback → midge larva → unicellular algae
B. ciliates → Daphnia → stickleback → dragonfly nymph
C. diatom → midge larva → caddisfly larva → stickleback
D. filamentous algae → mayfly nymph → leech → stickleback, 🗹🗹: C. diatom →
midge larva → caddisfly larva → stickleback
Q: In a pond, two species of fish feed on insects and worms. The insects feed on the
green plants that live in the water. What constitutes a population in this ecosystem?,
🗹🗹: All the fish of one species
Q: What is recycled in an ecosystem?, 🗹🗹: Nitrogen and carbon are recycled but not
energy.
Q: What best describes the mode of nutrition of a heterotroph?
A. It ingests only non-living organic matter.
B. It obtains organic molecules from other organisms.
C. It synthesizes its organic molecules from inorganic substances.
D. It produces its organic molecules from chemical reactions using light., 🗹🗹: B. It
obtains organic molecules from other organisms.
ib biology 4.1 and 4.2 Questions and
Answers (Expert Solutions)
Q: Define the term species?, 🗹🗹: Organisms that reproduce together to produce
fertile offspring
Q: The following statements refer to a pyramid of energy.
I. Some material is not assimilated by each trophic level.
II. Energy transformations are never 100 % efficient.
III. Heat is lost during photosynthesis.
Which of the statements give the reason why a pyramid of energy is narrower at the top
than at the bottom?
A. I only
B. I and II only
C. II and III only
D. I, II and III, 🗹🗹: B. I and II only
Q: What is a population?, 🗹🗹: Organisms of a species living together in the same
area
Q: Which pair of statements is correct?
A. autotroph-obtains organic molecules from other organisms heterotroph-synthesizes
organic molecules from inorganic molecules
B. autotroph-synthesizes organic molecules from inorganic molecules
heterotroph-obtains organic molecules from other organisms
C. autotroph-synthesizes inorganic molecules from organic molecules
heterotroph-synthesizes organic molecules from inorganic molecules
D. autotroph-obtains inorganic molecules from other organisms
heterotroph-obtains inorganic molecules from other organisms, 🗹🗹: B. autotroph-
synthesizes organic molecules from inorganic molecules
heterotroph-obtains organic molecules from other organisms
, Page | 2
Q: What is an ecosystem?, 🗹🗹: A community and its abiotic environment
Q: What term can be used to describe clams that eat decaying plant matter?, 🗹🗹:
Detritivores
Q: At each trophic level energy is lost. How is this energy regained by the ecosystem?,
🗹🗹: Photosynthesis
Q: In ecosystems the amterm-6ount of energy that passes from one trophic level to the
next is called the conversion efficiency. What is the average conversion efficiency from
primary to secondary consumers in most ecosystems?, 🗹🗹: 10 %
Q: What is the mode of nutrition of midge larva?, 🗹🗹: Heterotroph
Q: Which represents a correct food chain from this web?
A. stickleback → midge larva → unicellular algae
B. ciliates → Daphnia → stickleback → dragonfly nymph
C. diatom → midge larva → caddisfly larva → stickleback
D. filamentous algae → mayfly nymph → leech → stickleback, 🗹🗹: C. diatom →
midge larva → caddisfly larva → stickleback
Q: In a pond, two species of fish feed on insects and worms. The insects feed on the
green plants that live in the water. What constitutes a population in this ecosystem?,
🗹🗹: All the fish of one species
Q: What is recycled in an ecosystem?, 🗹🗹: Nitrogen and carbon are recycled but not
energy.
Q: What best describes the mode of nutrition of a heterotroph?
A. It ingests only non-living organic matter.
B. It obtains organic molecules from other organisms.
C. It synthesizes its organic molecules from inorganic substances.
D. It produces its organic molecules from chemical reactions using light., 🗹🗹: B. It
obtains organic molecules from other organisms.
