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IB Biology A4.1: Evo. & Spec. — Practice Questions & Answers
IB Biology A4.1 study notes: evidence for evolution, natural selection, the role of variation and reproduction, and how isolation drives speciation.
Here are 10 practice questions with full answers and explanations.
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Practice questions with answers
1
Multiple choice
What is the core definition of evolution?
Change in heritable characteristics of a population
Acquired traits in an individual's lifetime
Environmental adaptation
Sudden genetic mutations
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Why Evolution is defined as the change in heritable characteristics of a population over successive generations.
2
Multiple choice
How does the theory of evolution by natural selection stand in science?
As a pragmatic truth with extensive evidence
As a hypothesis lacking evidence
As a proven fact
As a falsified theory
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Why Evolution by natural selection is accepted as a pragmatic truth supported by extensive, diverse evidence.
3
Multiple choice
What type of evidence for evolution is derived from DNA and RNA sequences?
Evidence of common ancestry
Evidence of acquired characteristics
Evidence of environmental changes
Evidence of random mutations
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Why Similarities in DNA and RNA base sequences provide evidence of common ancestry between species.
4
Multiple choice
What does selective breeding demonstrate about evolutionary change?
It can occur rapidly
It only occurs over long periods
It is always beneficial
It is driven by natural selection
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Why Selective breeding shows that heritable change can occur rapidly when selection pressure is strong.
5
Multiple choice
What do homologous structures, like the pentadactyl limb, signify?
Common evolutionary origin
Convergent evolution
Analogous functions
Environmental adaptations
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Why Homologous structures like the pentadactyl limb share a common evolutionary origin despite differing functions.
6
Multiple choice
What is the process of convergent evolution?
The development of analogous structures
The development of homologous structures
The divergence of species
The extinction of species
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Why Convergent evolution is the independent development of analogous structures in unrelated organisms facing similar pressures.
7
Multiple choice
What are analogous structures defined by?
Similar function, different evolutionary origins
Similar evolutionary origins, similar functions
Different functions, different origins
Loss of function over time
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Why Analogous structures share similar function but arose from different evolutionary origins.
8
Multiple choice
What is the effect of speciation on the number of species?
Increases the number of species
Decreases the number of species
Has no effect
Causes species merging
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Why Speciation increases the number of species by splitting one ancestral population into two or more distinct species.
9
Multiple choice
What is essential for speciation?
Reproductive isolation
Increased gene flow
Geographic proximity
Identical environments
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Why Reproductive isolation is essential for speciation because it prevents gene flow, allowing populations to diverge.
10
Multiple choice
What role does differential selection play in speciation?
Drives divergence in isolated populations
Maintains genetic uniformity
Prevents isolation
Causes random mutations
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Why Differential selection drives divergence by favoring different traits in isolated populations facing different pressures.
Key terms in Evo. & Spec.
Evolution: The change in the heritable characteristics of a population over successive generations.
Natural selection: The process by which individuals with favourable heritable variations survive and reproduce more successfully, increasing the frequency of those alleles.
Adaptation: A heritable feature that increases an organism’s chance of survival and reproduction in its environment.
Homologous structures: Structures with the same basic plan inherited from a common ancestor, such as the pentadactyl limb, even where their functions differ.
Analogous structures: Structures with similar function but different evolutionary origin, produced by convergent evolution.
Heritable variation: Differences between individuals that can be passed to offspring, arising from mutation, meiosis and sexual reproduction.
Speciation: The formation of new species when populations become reproductively isolated and diverge.
Reproductive isolation: The prevention of interbreeding between populations, stopping gene flow and allowing divergence.
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