Zoology MCQs for NEET — Practice Questions with Answers

Oxygen was absent about 3.5 billion years ago. The early Earth's atmosphere was primarily composed of gases like methane, ammonia, water vapor, and hydrogen, but it lacked free oxygen. The presence of oxygen in the atmosphere began to increase significantly only after the advent of photosynthetic organisms.

Abiogenesis is the theory that life originated from non-living matter. This concept suggests that simple organic compounds could have formed under prebiotic conditions, eventually leading to the complex molecules and structures necessary for life.

Parallelism refers to the phenomenon where closely related groups evolve in similar ways due to similar environmental pressures, resulting in similar traits. This is known as adaptive convergence of closely related groups.

Vermiform appendix, nictitating membrane, and wisdom teeth in humans are considered vestigial organs. Vestigial organs are remnants of structures that had important functions in ancestors but are no longer useful in the same way.

The flight organs of animals such as locusts, bats, swallows, and flying fish are considered analogous. This means they have similar functions (flight) but evolved independently in different species, indicating convergent evolution.

Atavism refers to the reappearance of ancestral traits that had been lost through evolutionary changes. The appearance of facial hair in some people is an example of atavism because it is a trait that was present in our distant ancestors but is not commonly expressed in the modern human population.

Von Baer supports the theory of evolution based on embryological characters. He proposed that the development of an embryo (ontogeny) recapitulates the evolutionary history (phylogeny) of the species. This concept helps in understanding the evolutionary relationships among different species.

The biogenetic law, also known as Haeckel's recapitulation theory, states that 'ontogeny recapitulates phylogeny'. This means that the development of an organism (ontogeny) expresses all the intermediate forms of its ancestors (phylogeny). Essentially, the stages an embryo undergoes during development resemble the sequence of its evolutionary ancestors.

Herdmania is a member of the subphylum Urochordata (also known as Tunicata), which is part of the phylum Chordata. In Herdmania, chordate characteristics such as a notochord and a dorsal nerve cord are present in the larval stage but are lost in the adult stage. This is why Herdmania is included in Protochordata.