Free Evolution MCQs with Answers

• A. analogous
• B. homologous
• C. vestigial
• D. acquired

Explanation: Homologous organs share a common structural plan and a common embryonic origin because they were inherited from a shared ancestor, and…

• A. develop from the same embryonic tissue
• B. contain the same bones in the same order
• C. perform the same function but differ in structure and origin
• D. are both reduced and non functional

Explanation: Both are used for flight, but a bird wing is a modified vertebrate forelimb with bone inside while an insect wing is an outgrowth of the…

• A. Vermiform appendix
• B. Pancreas
• C. Diaphragm
• D. Thymus gland

Explanation: The appendix is the reduced remains of a large caecum that digests cellulose in herbivorous ancestors, and it can be removed with no loss…

• A. comparative embryology
• B. vestigial organs
• C. biochemical similarity between proteins
• D. the fossil record

Explanation: Fossils are the only evidence that shows extinct organisms themselves, arranged in dated rock layers, so they give an actual sequence of…

• A. fishes and amphibians
• B. amphibians and reptiles
• C. reptiles and birds
• D. reptiles and mammals

Explanation: Archaeopteryx had feathers and a wishbone like a bird but also teeth in its jaws, a long bony tail and clawed fingers like a reptile, so…

• A. more distantly related they are
• B. more closely related they are
• C. larger their genomes must be
• D. faster their mutation rate must be

Explanation: Sequence differences accumulate by mutation after two lineages separate, so a small number of differences means little time has passed…

• A. variations arise at random and are then selected
• B. characteristics acquired during an individual's lifetime are passed on to its offspring
• C. species are fixed and do not change
• D. populations evolve by chance changes in allele frequency

Explanation: Lamarck proposed that an organism changes during its own life in response to need and environment, and that these changes are transmitted…

• A. giraffes with longer necks survived and left more offspring
• B. a mutation in a growth gene lengthened the neck
• C. chance alone lengthened necks in a small isolated population
• D. each generation stretched its neck to reach higher leaves and the gain was inherited

Explanation: In Lamarck's account the effort of stretching lengthens the neck within the animal's own lifetime and the longer neck is then handed to…

• A. changes in body cells do not alter the genes carried in the germ cells
• B. organisms were found not to vary at all
• C. the fossil record showed no change over time
• D. no organ was ever found to degenerate through disuse

Explanation: Weismann's germ plasm idea, supported by his experiment of cutting off the tails of mice for many generations without shortening the tails…

• A. an organ that is constantly used becomes better developed while a disused organ degenerates
• B. all organs of the body remain unchanged throughout life
• C. organs change only when their genes mutate
• D. an organ once lost can never reappear in any descendant

Explanation: This is the first of Lamarck's two laws, and he used it to explain the strong limbs of a blacksmith, the webbed feet of water birds and…

• A. Overproduction of offspring
• B. Struggle for existence
• C. Inheritance of characters acquired during life
• D. Survival of the fittest

Explanation: Inheritance of acquired characters is Lamarck's proposal, not Darwin's, and it is the standard distractor in this question.

• A. Galapagos Islands
• B. Hawaiian Islands
• C. Canary Islands
• D. Maldive Islands

Explanation: During the voyage of HMS Beagle Darwin found that each island of the Galapagos group carried finches whose beaks matched the food…

• A. Philosophie Zoologique
• B. The Origin of Species
• C. Systema Naturae
• D. Principles of Geology

Explanation: The Origin of Species was published in 1859 and set out both the evidence for common descent and natural selection as its mechanism.

• A. genetic drift
• B. artificial selection
• C. inheritance of an acquired character
• D. natural selection

Explanation: Soot darkened the tree trunks, so pale moths became conspicuous to birds while the dark variant was camouflaged, and the frequency of the…

• A. why more offspring are produced than can survive
• B. how variations arise and how they are passed on
• C. the struggle for existence between individuals
• D. the geographical distribution of related species

Explanation: Darwin had no knowledge of genes, so although he built his whole argument on heritable variation he could not say where variation came…

• A. mutation and genetic recombination
• B. use and disuse of organs
• C. the needs felt by the organism
• D. the direct action of the environment on the gametes

Explanation: The modern synthesis keeps Darwin's natural selection and adds genetics: mutation creates new alleles and sexual reproduction shuffles…

• A. comparative anatomy of adults
• B. palaeontology
• C. biogeography
• D. comparative embryology

Explanation: Early vertebrate embryos resemble one another far more than the adults do, and structures such as pharyngeal pouches and a post anal tail…

• A. natural selection
• B. genetic drift
• C. artificial selection
• D. adaptive radiation

Explanation: Here a human being, not the environment, decides which individuals reproduce, and the chosen character is one that suits us rather than…

• A. the two colour forms of the peppered moth
• B. the reduced human appendix
• C. Darwin's finches evolving different beak shapes from one ancestral species
• D. the similarity of cytochrome c in humans and chimpanzees

Explanation: Adaptive radiation is the spread of one ancestral species into many descendant species, each adapted to a different niche, which is…

• A. bacteria learning to resist the drug during exposure
• B. the antibiotic causing the resistance mutation to occur
• C. each bacterium passing on resistance it acquired in its own lifetime
• D. survival and multiplication of resistant mutants already present in the population

Explanation: Resistance mutations arise at random before the drug is ever met, and the antibiotic then kills the sensitive majority, leaving the rare…