NEET BIOLOGY

Detailed explanation-1: -Asteroid impact, not volcanism, caused the end-Cretaceous dinosaur extinction.

Detailed explanation-2: -The Cretaceous-Paleogene extinction event is the most recent mass extinction and the only one definitively connected to a major asteroid impact. Some 76 percent of all species on the planet, including all nonavian dinosaurs, went extinct. Over a thousand dinosaur species once roamed the Earth.

Detailed explanation-3: -Sixty-six-million years ago, a nearly nine-mile-wide asteroid collided with Earth, sparking a mass extinction that wiped out most dinosaurs and three-quarters of the planet’s plant and animal species. Now we’re learning that the Chicxulub asteroid also generated a massive “megatsunami” with waves more than a mile high.

Detailed explanation-4: -However, it is believed that the most likely mechanism of an asteroid causing a mass extinction since the end of the Hadean Eon 4 billion years ago is to eject vaporized rock into the sky, where it spreads around the planet and reflects heat and light from the sun back into space.

Detailed explanation-5: -Also known as the Great Dying, it eradicated more than 95% of all species, including most of the vertebrates which had begun to evolve by this time. Some scientists think Earth was hit by a large asteroid which filled the air with dust particles that blocked out the Sun and caused acid rain.