Most Repeated MDCAT Biology: Evolution MCQs

Explanation

Cytochrome c is a respiratory protein found in all aerobic species. Cytochrome c is a small heme protein located in the inner mitochondrial membrane of eukaryotic cells. It plays a crucial role in the electron transport chain, a series of redox reactions that occur during cellular respiration.

Explanation

The idea that was not part of Charles Darwin's theory of evolution by natural selection is Option B: Variation between individuals arises by gene mutation. While Darwin acknowledged the existence of variation, he did not have a detailed understanding of the genetic mechanisms behind it, such as gene mutations.

Explanation

Carolus Linnaeus, regarded as the father of taxonomy, held the belief of special creation. He posited that species were created directly by God and remained unchanged. While he recognised the possibility of new species forming within certain limits, his views fundamentally opposed the concept of natural selection, which involves species evolving over time. Linnaeus's beliefs also contrasted with catastrophism, a geological theory, and the inheritance of acquired characters, a biological theory associated with Lamarck. These latter theories involve changes in species, which Linnaeus did not endorse.

Explanation

Among the birds Darwin collected on the Galapagos were 13 types of finches that, although quite similar, seemed to be different species. Some were unique to individual islands, while other species were distributed on two or more islands that were close together. This shows divergence in the evolution.

Explanation

Darwin's theory of evolution rests on three main points: 'Descent with Modification,' which refers to the passing on of traits from parent to offspring with changes over generations; 'Natural Selection,' which is the process by which certain traits become more common in a population due to their advantage in survival and reproduction; and 'Adaptation,' which is the process by which species become better suited to their environment. Other options mention related concepts but miss one or more of these key points.

Explanation

Genetic drift is a mechanism of evolution, it refers to random fluctuations in the frequencies of alleles from generation to generation due to chance of events, therefore the answer will be B.

Explanation

The term "survival of the fittest" was used by Herbert Spencer, an English philosopher and scientist. It is closely related to Charles Darwin's theory of natural selection. The phrase suggests that individuals who are best suited to their environment and possess advantageous traits have a greater likelihood of survival and passing on those traits to their offspring. It's all about the idea that the most adaptable and well-suited organisms are more likely to thrive in their surroundings.

Explanation

Jean-Baptiste Lamarck (1744-1829) proposed the theory of inheritance of acquired characteristics, also known as Lamarckism. He suggested that organisms can pass on traits they acquire during their lifetime to their offspring. For example, he believed that giraffes developed long necks because they stretched to reach leaves, and then passed this trait to their offspring.However, this theory was later disputed and largely discredited by the scientific community, particularly after the discovery of genetics and the modern synthesis of evolution.

Explanation

Prokaryotes are the oldest known organisms.They are about 3.5 million years ago. So it follows that the oldest fossils would be of prokaryotes as well. Option A is the correct option.

Explanation

A. I is not right since a community involves different populations which may have different gene pool.B. II is also not right since different populations may interact in different ways with each other and disturb the genetic pool and stability.C. III is right and is a fact.D. IV is also right since intra-specific interactions are more common than inter-specific interactions in communities.Hence III and IV are the right options (Option D).