Natural Selection Quiz

Grade 8 · Science · Quiz

10 questions on Darwin's theory, adaptations, fitness, and real-world examples of natural selection.

Questions

Who proposed the theory of evolution by natural selection?
1. Gregor Mendel
2. Louis Pasteur
3. Charles Darwin
4. Isaac Newton
Show answer
Answer: Charles Darwin
Charles Darwin developed the theory of evolution by natural selection, published in 'On the Origin of Species' in 1859.
In natural selection, 'fitness' refers to:
1. Physical strength
2. An organism's ability to survive and reproduce
3. How fast an organism can run
4. The size of an organism
Show answer
Answer: An organism's ability to survive and reproduce
Fitness in biology means reproductive success — passing genes to the next generation.
Natural selection can only occur if there is genetic variation in a population.
Show answer
Without variation, all individuals are equally likely to survive — there is nothing for selection to act on.
Which of the following is the best example of an adaptation?
1. A student learns to play piano
2. A giraffe's long neck for reaching leaves
3. A dog learns to sit on command
4. A plant bends toward sunlight during its lifetime
Show answer
Answer: A giraffe's long neck for reaching leaves
An adaptation is an inherited trait — the long neck is heritable and improves survival. Learned behaviors and temporary responses are not adaptations.
The peppered moth changed from mostly light-colored to mostly dark-colored during the Industrial Revolution because:
1. Light moths learned to change color
2. Pollution turned the trees dark, making dark moths harder to spot by predators
3. Dark moths migrated in from other regions
4. Light moths became sick from pollution
Show answer
Answer: Pollution turned the trees dark, making dark moths harder to spot by predators
Environmental change (soot-covered trees) shifted the selective pressure — dark moths had better camouflage and higher survival rates.
Natural selection requires variation, heritability, overproduction, and ___ survival.
Show answer
Differential survival means some individuals survive and reproduce better than others — the core mechanism of natural selection.
Overproduction in natural selection means:
1. Organisms produce too many offspring to all survive
2. Organisms eat too much food
3. The environment produces too many resources
4. Organisms grow too large
Show answer
Answer: Organisms produce too many offspring to all survive
Overproduction creates competition for limited resources, so only the best-adapted individuals survive — driving selection.
Natural selection can lead to new species over long periods of time.
Show answer
When populations become isolated and face different selective pressures, they diverge genetically and can eventually become separate species — a process called speciation.
A population of fish lives in a cave with no light. Over many generations, most become blind. This is best explained by:
1. The fish chose not to use their eyes
2. Natural selection — fish with eyes had no advantage, so eyeless mutations accumulated
3. The fish adapted during their lifetimes
4. Artificial selection by humans
Show answer
Answer: Natural selection — fish with eyes had no advantage, so eyeless mutations accumulated
In a dark environment, eyes provide no benefit. Energy spent developing eyes is wasted, so fish with eye-reducing mutations survived equally well (or better), and the trait spread.
Which of the following provides the raw material (variation) for natural selection?
1. Environmental pressure
2. Mutations and genetic recombination
3. Learned behaviors
4. Overproduction of offspring
Show answer
Answer: Mutations and genetic recombination
Mutations create new alleles, and sexual reproduction shuffles alleles — both generate the genetic variation that natural selection acts upon.

Get a personalized course on Natural Selection built around your child.