Evolution MCQ Quiz - Objective Question with Answer for Evolution - Download Free PDF

• The founder effect occurs when a small group of individuals becomes isolated from a larger population and establishes a new population. This new group may have different allele frequencies than the original population, leading to reduced genetic variation.
• Because the new population is established by a small number of individuals, certain genes that were rare in the original population may become more common, and vice versa.
• The founder effect is a type of genetic drift, where random changes in allele frequencies can have significant impacts on the genetic diversity of small populations.

• Rationale: Industrial melanism is the phenomenon where darker-colored individuals become more common in a population due to industrial pollution, which darkens the environment and provides a selective advantage to these individuals. This is an example of natural selection rather than genetic drift.

• Rationale: Adaptive radiation is the process by which a single ancestral species rapidly diversifies into a multitude of new forms, particularly when a change in the environment makes new resources available. This is driven by natural selection and ecological opportunities, not genetic drift.

• Rationale: Mutation effect refers to changes in the genetic code that can introduce new alleles into a population. While mutations are a source of genetic variation, they are not the same as genetic drift or the founder effect, which involve changes in allele frequencies due to random sampling.

• The founder effect is the correct term for the scenario where a small group of individuals from an original population becomes isolated and forms a new population with different genetic characteristics. This effect is a type of genetic drift and can significantly impact the genetic diversity of the new population.

The correct answer is It suggests that organisms can acquire new characteristics through use or disuse of body parts.

Key Points

• Lamarck's theory of evolution is also known as the theory of inheritance of acquired characteristics.
• Lamarck proposed that organisms can develop new traits during their lifetime through the use or disuse of particular body parts.
• These acquired traits are then passed on to the next generation, leading to evolutionary changes over time.
• For example, Lamarck suggested that the long neck of a giraffe evolved because ancestors stretched their necks to reach leaves high in trees, and this trait was inherited by their offspring.
• This theory was one of the earliest models of evolution proposed before Darwin's theory of natural selection.

Additional Information

• Jean-Baptiste Lamarck was a French naturalist who is best known for his contribution to the early theories of evolution.
• Lamarck's theory was later largely discredited by the scientific community, especially after the development of the modern understanding of genetics and Darwin's theory of natural selection.
• Darwin's theory of natural selection contrasts with Lamarck's ideas by suggesting that evolution occurs through the differential survival and reproduction of individuals with advantageous traits, rather than the inheritance of acquired characteristics.
• The concept of use and disuse in Lamarck's theory implies that body parts that are used extensively become stronger and more developed, while those that are not used deteriorate over time.
• Despite its inaccuracies, Lamarck's work was significant in the history of evolutionary thought as it introduced the idea that organisms are capable of change over time.

The correct answer is Evolution through Inheritance.

Key Points

• Natural selection is a core component of Darwin's theory, explaining how traits that enhance survival become more common in successive generations.
• Survival of the fittest refers to the process by which individuals better adapted to their environment tend to survive and reproduce more successfully.
• Struggle for existence of life describes the competition between organisms for limited resources such as food, shelter, and mates.
• Darwin did not include the mechanism of inheritance in his theory, as the concept of genetic inheritance was not understood at the time.
• Darwin's theory primarily focused on the role of natural selection in driving evolution rather than the specifics of how traits were inherited.

Additional Information

• Genetic Inheritance
  • Genetic inheritance involves the transmission of genetic information from parents to offspring through genes.
  • Gregor Mendel's work on pea plants laid the foundation for understanding genetic inheritance, although it was not known to Darwin.
• Modern Synthesis
  • The modern synthesis of the early 20th century integrated Darwin's theory of evolution with Mendelian genetics.
  • This synthesis provided a more comprehensive understanding of how evolutionary processes operate at the genetic level.
• Speciation
  • Speciation is the process by which new species arise from existing ones, a concept that is central to evolutionary biology.
  • Darwin's theory laid the groundwork for understanding how speciation occurs through gradual changes over time.

The correct answer is All i.e. Excavation, Time dating, determining DNA sequence.

Explanation-

All three- time dating, determining DNA sequence, and excavation can be used for studying human evolution. 

• Time Dating: Also known as radiometric dating or carbon dating, this method is used to determine the age of fossils, including remains or artifacts associated with early humans. Understanding an artifact's age enables scientists to place it within a specific time frame in the chronology of human evolution, aiding in the construction of a timeline for the appearance and development of different hominid species and their characteristics.
• Determining DNA Sequence: By analyzing and comparing the DNA sequences of modern humans and other species, such as our closest existing relatives, the chimpanzees, and extinct hominids like Neanderthals and Denisovans (from their preserved DNA), scientists can infer evolutionary relationships and estimate the times of divergence of different lineages. Genetic studies can provide information about traits, population sizes, migration patterns, and interbreeding events in our ancestral history.
• Excavation: Archaeological excavation allows for the extraction of physical evidence from ancient times. Discoveries can be diverse—ranging from human and animal remains to tools, artifacts, and environmental data. All these findings we get from the excavation form the core of the paleo-anthropological record that enables us to document and interpret human evolution.

Concept:

• Analogy is the study of organisms with structures that are not anatomically similar but perform similar functions. There is no common ancestor between the two organisms. They are actually a product of convergent evolution. Example of analogy includes the structure of wings of a butterfly and of birds that are not looking anatomically similar but they perform similar functions.
• Homology is the study of organisms with similar anatomical structures.  Homologous organs evolved from the common ancestor. Homologous structures are a result of divergent evolution which explains that the same structures are developed along with different directions due to adaptations to different needs. An example includes the pattern of bones of forelimbs of frogs, lizards, birds, and humans that share similarities in their structures but performs different functions according to their needs in these animals.

Explanation:

• Homologous and analogous structures are often confused, Homologous organs have the same origin but perform different functions while analogous organs have different origins but perform the same functions 

Concept:

• Analogy is the study of organisms with structures that are not anatomically similar but perform similar functions. There is no common ancestor between the two organisms. They are actually a product of convergent evolution. Example of analogy includes the structure of wings of a butterfly and of birds that are not looking anatomically similar but they perform similar functions.
• Homology is the study of organisms with similar anatomical structures.  Homologous organs evolved from the common ancestor. Homologous structures are a result of divergent evolution which explains that the same structures are developed along with different directions due to adaptations to different needs. An example includes the pattern of bones of forelimbs of frogs, lizards, birds, and humans that share similarities in their structures but performs different functions according to their needs in these animals.

Explanation:

• Homologous and analogous structures are often confused, Homologous organs have the same origin but perform different functions while analogous organs have different origins but perform the same functions 

• Somatic Mutation is not hereditary.
• Somatic Mutation is defined as the alteration in DNA that occurs after conception.
• It can occur in any of the cell body except the germ cells and therefore is not hereditary.

The correct answer is metamorphosis.

Key Points

• Metamorphosis process: The transformation of the larva into an adult through drastic changes is called metamorphosis. It is a biological process that involves sudden and abrupt changes in the body structure of the animal by cell growth and differentiation. It is generally observed in amphibians and insects. Examples: frogs and butterflies.

Important Points

• Metamorphosis of a butterfly
  • There are four stages in the process of the Metamorphosis of a butterfly.
  • The first stage is the egg.
  • The Butterfly eggs are laid on the plants by the female Butterfly.
  • The second stage is the larva stage in which the butterfly exists in the form of a caterpillar.
  • The Third stage is Pupa which is the transitional phase in which the Caterpillar changes into Butterfly.
  • The fourth stage is the Adult stage in which a full-grown adult butterfly comes out of the pupa.

Additional Information

• Complete metamorphosis is seen in butterflies. 
• Complete metamorphosis consists of a very active, ravenously eating larval stage and an inactive pupa stage while the incomplete metamorphosis has a nymph, which very closely resembles the adult
• Examples of insects showing Complete metamorphosis -  wasps, ants, butterflies, and fleas  
• Examples of insects showing Incomplete metamorphosis - are termites, praying mantis, and cockroaches

• ‘Proboscis’ with reference to an elephant is its trunk.
• Elephants are a warm-blooded animal. They are classified in Class- Mammalia. Their body is divided into head, neck, trunk and tail.
• According to Elephant Census 2017, their population at 27, 312 across 23 states in India.
• Environment Ministry has declared Elephant as India’s national heritage animal.
• According to the International Union for Conservation of Nature (IUCN), the population of Asian elephants was about 41,410 to 52,345.
• India alone accounts for nearly 60% of Asian Elephants population.

Key Points

• Complicated organs cannot be generated by a single DNA change
• They will be created bit-by-bit over generations
• This step-by-step change over many generations and millions of years produces complex organisms
• This is called evolution by stages 
• It does not happen in one stage but required many stages of gradual change
• At each successive evolutionary stage, the organ becomes more complex and adapted

Hence, evolution by stages, means complex organs arise as a result of small changes over several generations (option 4)

Important Points

• Eye is a very popular adaptation, found in insects, octopuses, and vertebrates
• Structure of the eye in each organism is different, indicating separate evolutionary origin
• The rudimentary eye evolved to become complex and adapted to the requirement of different species
• Evolutionary change that is useful for one property can later be used for a different function
• Feathers started out as a means for providing insulation but became useful for flight
• Similarly, for eyes, they can be simple, complex, with different rotation, and multiple lenses depending on the requirements of the species
• All these eyes probably started as rudimentary eyes but became complex as organisms continued to evolve
• There was no single event or change making them this complex, i.e., it did not happen in a single stage
• It happened slowly over millions of years, i.e., in many stages.

Explanation:
Tracing evolutionary relationship - 

• These morphological changes in the eye or any such evolving organ are accompanied by a similar change in the DNA
• This DNA change can be used for tracing evolutionary relationship
• Comparing the DNA of different species gives us an estimate of how DNA changed during formation of species
• This method is now used to identify evolutionary relationships.

Concept:

• The first theory of evolution was proposed by Lamarck.
• Lamarckism or Lamarckian inheritance is also known as "Neo-Lamarckism". 

Important Points

• Lamarck says that an organism can pass on to its offspring physical characteristics that the parent organism acquired through use or disuse during its lifetime.
• This idea is also called the inheritance of acquired characteristics.
• Example in support of Lamarckism-
  • Long necks and high forelimb of Giraffe.
  • Snakes lost their legs.
  • Retractile claws of carnivorous animals.

​Explanation:

• The theory was explained with the example of giraffe.
• It was stated the giraffe ancestors stretched their necks to reach out to the leaves on higher branches of a tree.
• This ones with longer neck were more successful in getting food and produced offspring with longer necks.
• This theory formed the early basis of biological evolution and also influenced Darwin's theory.
• It was rejected later in the mid-twentieth century because of lack of experimental proof.

Additional Information

• Mutation theory was proposed by Hugo-de-Vries.
• The theory of Natural Selection was proposed by Darwin and Wallace.

Concept:

• The founder effect occurs when a small population gets drifted from the parent population and becomes a new population.
• Allele frequency changes as compared to their parent population and thus forming a new population with a new genotype.

Explanation:

• Option 1: Genetic drift is the change in allele frequencies that occurs by chance. It occurs in a small population. The founder effect is a result of genetic drift.
• Option 2: Natural selection is a process by which the organism more fitted to the environment will survive and reproduce to form more of its kind. They are more adapted to their environment.
• Option 3: Genetic recombination is the process of the exchange of DNA fragments between two different chromosomes leading to variation.
• Option 4: Mutation is the change in DNA sequence due to errors in DNA replication, any exposure to mutagens, etc.

So, the correct answer is option 1.

Concept -

• Charles Darwin made a sea voyage around the world on a ship named H.M.S. Beagle.
• Charles Robert Darwin gave the theory of evolution by natural selection.
• The theory was known as the theory of natural selection.
• He explained the process by which organisms change over time as a result of changes in behavioural traits.
• He proposed this theory in his book “The Origin of Species”.
• He gave an explanation of the formation of new species i.e. various species evolve from single species through adaptation to the environment.
• He is also known as the father of evolution.

Explanation-

• Darwin explained that variations appearing due to environmental changes are transmitted to the next generation.
• So offspring become different from ancestors.
• In the next-generation process of Natural selection repeats so after many generations, a new species is formed.

Therefore the theory of the origin of species by natural selection was given by Charles Darwin.

Additional Information

• The theory of Natural Selection was proposed by Darwin and Wallace.
• The theory of continuity of germplasm by Weismann.
• Evolution term introduced by H. Spencer.

• There are four stages in the process of Metamorphosis of a butterfly.
• The first stage is the egg.
• The Butterfly eggs are laid on the plants by the female Butterfly.
• The second stage is the larva stage in which the butterfly exists in the form of a caterpillar.
• The Third stage is Pupa which is transitional phase in which the Caterpillar changes into Butterfly.
• The fourth stage is the Adult stage in which a full grown adult butterfly comes out of the pupa.

• Marsupials are the mammal of an order whose members are born incompletely developed and are typically carried and suckled in a pouch on the mother's belly.
• The distinctive characteristic of 'Marsupials' is that they carry their young ones in pouches.
• They take their name Marsupials from the word 'Marsupium' means pouch which protects eggs, offspring, or reproductive structures.
• The main examples of Marsupials animals are kangaroos, wallabies, koalas, possums, opossums, wombats, and Tasmanian devils.