All Free Biology MCQs with Answers

• A. Gene
• B. Individual
• C. Group
• D. All

Explanation: Natural selection only occurs at the individual levels.

• A. Use and disuse of organs
• B. Inheritance of acquired characters
• C. Natural selection
• D. Both A and B

Explanation: Lamarck's theory of evolution is based on two main ideas: The use and disuse of organs: Lamarck believed that the organs that are used…

• A. When the populations begin to eat different foods
• B. When there is a physical barrier, such as a river
• C. When the two populations have not been in contact with one another for two hundred years
• D. When they are no longer able to interbreed

Explanation: option D is correct as two populations of the same species can be considered different species when they are unable to interbreed and…

• A. How giraffes get their long neck
• B. How humans lost their tail
• C. How humans became bipedal
• D. All of these

Explanation: Lamarckism is a theory of evolution that states that acquired characteristics can be inherited.

• A. No Signs
• B. Observable signs
• C. Non-observable signs
• D. Fusing signs

Explanation: Evolution leaves observable signs. These observable signs of evolution collectively support the theory of evolution and demonstrate the…

• A. Cantbury in western England
• B. Shrewsbury in western England
• C. Cantbury in eastern England
• D. Shrewsbury in eastern England

Explanation: Charles Darwin was born in 1809 in Shrewsbury, England. His father, a doctor, had high hopes that his son would earn a medical degree at…

• A. Morphological similarities
• B. Fossil record
• C. Vestigial characteristics
• D. This is the correct answer because all the given options are correct.

Explanation: Morphological similarities mean similarities in structures and forms. These similarities give the idea that the organisms have evolved…

• A. New Zealand
• B. New Guinae
• C. Galapagos island
• D. Australia

Explanation: Darwin finches (13 types) are found in the Galapagos islands, west of Ecuador.

• A. Homologous structures result from a common ancestor; analogous structures result from repetitive usage by the individual
• B. Homologous structures result from covergent evolution, analogous structures result from common ancestors
• C. Both Options A and B are correct
• D. Homologous structures result from a common ancestor, analogous structures come from convergent evolution

Explanation: The correct answer is Homologous structures result from a common ancestor, analogous structures come from convergent evolution.

• A. A trait that makes an organism better suited to a habitat
• B. A structure that has origins in a common ancestor, but has evolved to perform different functions
• C. A change to a cell's genome
• D. A structure that has lost its function but has been retained

Explanation: Option D is correct as a vestigial trait is a characteristic of a species that was lost by evolution due to lack of need for that trait.

• A. Vestigial organs
• B. Fuel
• C. Fossils
• D. All of these

Explanation: Fossils are the preserved remains of plants and animals whose bodies were buried in sediments, such as sand and mud, under ancient seas…

• A. Artificial selection
• B. Founder Effect
• C. Bottleneck affect
• D. Both A and B

Explanation: The bottleneck effect is an extreme example of genetic drift that happens when the size of a population is severely reduced.

• A. Homologous structures result from a common ancestor; analogous structures result from repetitive usage by the individual
• B. Homologous structures result from convergent evolution; analogous structures result from a common ancestor
• C. There is no difference between homologous and analogous structures
• D. Homologous structures result from a common ancestor; analogous structures result from a convergent evolution

Explanation: Homologous organs are those which have a ancestor in common but diverge to perform different functions and thus, representing divergent…

• A. The frequency of alleles does not change within the population
• B. It reduces the number heterozygous individuals, preventing beneficial alleles from being efficiently selected for
• C. It increases the number of homozygous individuals, allowing potentially harmful recessive alleles to express themselves more frequently
• D. All of these

Explanation: The candidate first must know, what inbreeding means and then judge the options in accordance.

• A. Individuals lose traits that they don't need
• B. Acquired characteristics are inheritable
• C. Individuals gain characteristics they need
• D. All of these

Explanation: Option D is correct as all of the options A, B, and C are correct. Lamarck's theory of evolution is based on two main ideas: The use and…

• A. The number of offspring produced by the organism X
• B. How much food the organism consumes in its lifetime
• C. How large the organism grows
• D. The number of offspring produced by the organism's own offspring

Explanation: Fitness is a measure of how well an organism is able to survive and reproduce in its environment.

• A. Survival of the fittest
• B. Most fit individuals adapt to their environment better than less fit individuals
• C. Those who eat better are healthier and live longer are most fit within a population
• D. Preservation of traits leads to increase survival and reproduction

Explanation: Survival of the fittest is a phrase that was coined by Herbert Spencer, but it was first used by Charles Darwin in his book On the Origin…

• A. Genetic variations can be inherited
• B. Members of a population produce more offspring than the environment can support
• C. Accumulation of adaptations leads to speciation
• D. All are true.

Explanation: Given all statements reflect Darwin's theory of evolution as true. Darwin's theory of evolution is described by the following statements…

• A. Mitochondria and other plastids multiply by binary fission
• B. Mitochondria contain their own DNA, which is a single circular chromosome
• C. Mitochondria have their own ribosomes, which are 70s
• D. None of these options are correct

Explanation: OPTION A: Mitochondria and other plastids (such as chloroplasts) multiplying by binary fission is a key piece of evidence supporting the…

• A. How giraffes got their long neck
• B. How humans lost their tail
• C. How humans became bipedal
• D. All of these options are correct

Explanation: The ideas about evolution presented by Lamarck are known as Lamarckism.