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Evolution and Natural Selection: Practice Questions with Answers

Curriculum: Evolution And Natural SelectionGrades: 8–10Questions: 12Mode: Practice

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1. What is natural selection?

  1. A method scientists use to breed pets in a laboratory
  2. The process by which all organisms in a species change at the exact same rate
  3. The process by which organisms with traits better suited to their environment tend to survive and reproduce more successfully
  4. The process by which animals choose their own mates based on color alone
Show the answer
Answer: C. The process by which organisms with traits better suited to their environment tend to survive and reproduce more successfully
Natural selection means individuals with helpful traits are more likely to survive and pass those traits to offspring, which gradually shapes the traits common in a population.

2. Which scientist is most famous for developing the theory of evolution by natural selection?

  1. Isaac Newton
  2. Louis Pasteur
  3. Gregor Mendel
  4. Charles Darwin
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Answer: D. Charles Darwin
Charles Darwin published his ideas on natural selection in 1859 after studying wildlife, including finches on the Galapagos Islands.

3. What is a 'trait' in the context of biology?

  1. A type of habitat where an organism lives, such as a forest, desert, or pond
  2. A characteristic or feature of an organism, such as fur color or beak shape
  3. The scientific name given to a species, such as Homo sapiens for humans
  4. A learned behavior seen just in humans, such as reading, writing, or cooking
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Answer: B. A characteristic or feature of an organism, such as fur color or beak shape
A trait is any observable characteristic of an organism, like height, color, or shape, that can be influenced by genes.

4. Why is variation within a population important for natural selection?

  1. Variation gives some individuals traits that help them survive and reproduce better than others in a given environment
  2. Variation makes every individual identical, which helps the species survive
  3. Variation has no effect on which individuals survive
  4. Variation only matters for plants, not animals
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Answer: A. Variation gives some individuals traits that help them survive and reproduce better than others in a given environment
Without differences among individuals, natural selection would have nothing to act on, since some variations must be more useful than others for a population to change over time.

5. What does 'survival of the fittest' mean in evolutionary biology?

  1. Organisms best suited to their environment are more likely to survive and reproduce
  2. The fastest organisms always win in nature
  3. Every organism has an equal chance of surviving regardless of traits
  4. Only the physically strongest animals survive
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Answer: A. Organisms best suited to their environment are more likely to survive and reproduce
'Fittest' refers to how well an organism's traits match the demands of its environment, not just physical strength or speed.

6. What is an adaptation?

  1. Any random change with no benefit to the organism
  2. An inherited trait that helps an organism survive and reproduce in its environment
  3. A trait that develops in one day and disappears the next
  4. A skill an animal learns during its lifetime, like a trick
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Answer: B. An inherited trait that helps an organism survive and reproduce in its environment
Adaptations are inherited features, such as camouflage or a specialized beak, shaped over generations because they improve survival or reproduction.

7. What is a mutation?

  1. A trait an animal gains from exercising and then passes on to its young
  2. A disease caused by pollution that spreads from one organism to another
  3. A change in an organism's DNA sequence that can create new genetic variation
  4. The process by which two different species merge together to form a single new species
Show the answer
Answer: C. A change in an organism's DNA sequence that can create new genetic variation
Mutations are changes in DNA that can be neutral, harmful, or occasionally helpful, and they are an important source of new genetic variation in populations.

8. In the classic example of the peppered moth in England, why did dark-colored moths become more common during the Industrial Revolution?

  1. Light-colored moths went extinct because the plants they fed on died from factory pollution in the cities
  2. Factories released dark-colored moths into the wild to replace the light moths killed by smoke and pollution
  3. Dark moths could fly faster than light moths, so they were better at escaping from the birds that hunted them
  4. Soot darkened tree bark, so dark moths were better camouflaged from predators than light moths
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Answer: D. Soot darkened tree bark, so dark moths were better camouflaged from predators than light moths
As pollution darkened tree trunks, light-colored moths became easier for birds to spot, while dark moths blended in and survived to reproduce more often.

9. What is artificial selection?

  1. A type of evolution that only happens in laboratories with chemicals
  2. A process where nature randomly selects traits with no human involvement
  3. The process where humans breed organisms with specific desired traits, such as in dogs or crops
  4. The extinction of a species due to human activity
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Answer: C. The process where humans breed organisms with specific desired traits, such as in dogs or crops
Artificial selection is when humans, rather than nature, choose which organisms reproduce, such as breeding cows for more milk or dogs for certain sizes.

10. What is a fossil, and how does it provide evidence for evolution?

  1. A fossil is the preserved remains or traces of an ancient organism that can show how species changed over time
  2. A fossil is a living organism found only in oceans that has not changed in millions of years
  3. A fossil is a type of rock with no biological connection, formed only by heat and pressure
  4. A fossil is a photograph of an ancient animal taken by early scientists during expeditions
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Answer: A. A fossil is the preserved remains or traces of an ancient organism that can show how species changed over time
Fossils record physical evidence of organisms from the past, and comparing older and younger fossils lets scientists trace gradual changes in body structures over time.

11. What are homologous structures?

  1. Structures found only in plants
  2. Structures that appear identical but come from completely unrelated ancestors
  3. Body parts that all serve the exact same function in every species
  4. Similar body structures in different species that suggest a shared ancestor, like the bones in a human arm and a bat wing
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Answer: D. Similar body structures in different species that suggest a shared ancestor, like the bones in a human arm and a bat wing
Homologous structures share a similar bone arrangement even though they may look different and do different jobs, which is strong evidence of common ancestry.

12. What is common ancestry?

  1. The idea that species can never be related to one another
  2. The idea that only humans have ancestors
  3. The idea that all animals were created at the same instant with no relation to each other
  4. The idea that different species share an earlier ancestor species from which they both descended
Show the answer
Answer: D. The idea that different species share an earlier ancestor species from which they both descended
Common ancestry explains why related species share similar DNA and body structures: they inherited these features from a shared ancestor further back in time.
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