Evolution MCQs for NEET — Zoology Questions with Answers

The era called the ‘age of prokaryotic microbes’ is known as the Archaezoic era. This era is characterized by the dominance of prokaryotic life forms, such as bacteria and archaea, before the emergence of more complex eukaryotic life forms.

Stanley Miller's experiment, conducted in 1953, aimed to simulate the conditions of the early Earth's atmosphere. The apparatus he used contained a mixture of hydrogen, ammonia, methane, and water vapour. This combination was chosen based on the hypothesis that the early Earth had a reducing atmosphere, which is conducive to the formation of organic molecules. The experiment demonstrated that amino acids and other organic compounds could form spontaneously under these conditions, supporting the theory of abiogenesis.

The famous experiment to prove the origin of life was conducted by Stanley Miller and Harold Urey in 1953. Known as the Miller-Urey experiment, it simulated the conditions thought to be present on the early Earth and demonstrated that organic molecules necessary for life could be synthesized from inorganic precursors under these conditions. This experiment provided significant evidence supporting the theory of abiogenesis, the idea that life arose naturally from non-living matter.

The statement A is true because the first molecules thought to be formed for replicating cells were RNA, which is supported by the RNA world hypothesis. This hypothesis suggests that RNA, which can both store genetic information and catalyze chemical reactions, was the first self-replicating molecule. The statement R is also true because Thomas Cech's discovery of ribozymes in 1987 provided evidence that RNA could have catalytic functions. Therefore, R is the correct explanation for A.

The correct matches are: I (Core of the earth) – B (Fe-Ni), II (Life originated) – A (Archaeozoic era), III (Stromatolites) – D (Photosynthesizing algae), IV (TMC is an example) – C (Inter-micromolecular assembly). The core of the Earth is composed of iron and nickel (Fe-Ni). Life is believed to have originated during the Archaeozoic era. Stromatolites are layered structures formed by photosynthesizing algae. TMC (Thermochemical conversion) is an example of an inter-micromolecular assembly.

Coacervates are colloidal droplets and they contain nucleoproteins. Coacervates are formed when organic molecules, such as proteins and nucleic acids, aggregate into microspheres. These droplets can encapsulate enzymes and other molecules, creating a primitive form of compartmentalization that is essential for the beginning of life processes. Therefore, both options 1 and 2 are correct.

The earliest organisms were heterotrophic and anaerobic because the early Earth lacked oxygen in its atmosphere. These organisms obtained their energy by consuming organic molecules present in their environment and did not require oxygen for their metabolic processes.

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.