Evolution MCQs for NEET — Zoology Questions with Answers

New species are typically formed through variations. Variations are the differences in DNA among individuals within a species. These variations can lead to changes in traits over generations, which may eventually result in the emergence of a new species if the variations are significant and persistent. Therefore, the correct answer is 'variations'.

Both statements X and Y are true. During evolution, species have indeed developed their internal environments to make physiological processes more efficient (Statement X). Additionally, organisms show various adaptations to survive and thrive in their specific environments (Statement Y). These adaptations can be structural, physiological, or behavioral.

An alternative form of a gene is known as an allele. Alleles vary in their sequence which may or may not result in a variant phenotype of a particular trait. Alleles represent variations of a gene that is responsible for a particular trait. eg: ABO blood groups in humans are a good example of multiple alleles.

Gregor Mendel's work on garden peas laid the foundation for understanding the inheritance of specific traits. His experiments and subsequent laws of inheritance explained how traits are passed from parents to offspring, making heredity clearer.

Microevolution refers to small-scale changes within a species, primarily due to genetic variations that occur at the level of genes (blastogenic variation). These genetic changes can lead to differences in traits within a population.

The primary difference between Homo erectus and Homo sapiens is in the size of their brains. Homo erectus had a smaller brain relative to Homo sapiens. This difference is significant in terms of the cognitive and technological advancements that are attributed to Homo sapiens.

Analogous structures are those that have similar appearance and function but different underlying structures. This occurs due to convergent evolution, where unrelated species evolve similar traits independently, usually as a result of having to adapt to similar environments or ecological niches.

Jean-Baptiste Lamarck was a predecessor of Darwin who developed the theory of acquired characteristics. According to Lamarck, traits acquired by an organism during its lifetime could be passed on to its offspring. This theory was later refuted by the understanding of genetics and inheritance.