NEET Biology Evolution MCQs Set 08

Answer: (a) evolutionary biology

Explanation:
1. Evolutionary biology studies how life forms have changed over time.
2. It covers the origin and history of life.

Teacher's Note:
1. Evolution means gradual change over generations.
2. Fossils are one line of evidence.

Answer: (d) light years

Explanation:
1. A light year is the distance travelled by light in one year.
2. It is used for very large distances.

Teacher's Note:
1. The universe is huge.
2. So special units are used.

Answer: (a) 20 billion years

Explanation:
1. NCERT gives the age of the universe as nearly 20 billion years.
2. The earth is much younger.

Teacher's Note:
1. The earth is about 4.5 billion years old.
2. Life is younger than the earth.

Answer: (b) 4.5 billion years back

Explanation:
1. The earth formed about 4.5 billion years ago.
2. There was no atmosphere at first.

Teacher's Note:
1. The early atmosphere had water vapour, methane, CO2 and ammonia.
2. It had no free oxygen.

Answer: (c) CH4, H2, NH3 and water vapour

Explanation:
1. Miller used CH4, H2, NH3 and water vapour at 800°C.
2. He obtained amino acids.

Teacher's Note:
1. The mixture had no free oxygen.
2. It was like the early atmosphere.

Answer: (c) Charles Darwin

Explanation:
1. Darwin made his observations during a sea voyage round the world on H.M.S. Beagle.
2. He saw many varieties of finches in the Galapagos.

Teacher's Note:
1. Darwin's voyage lasted five years.
2. It led to the theory of natural selection.

Answer: (b) natural selection

Explanation:
1. Darwin said that nature selects the fittest variants.
2. Their numbers increase over generations.

Teacher's Note:
1. Lamarck proposed use and disuse.
2. Darwin proposed natural selection.

Answer: (c) palaeontology

Explanation:
1. Palaeontology is the study of fossils.
2. Palynology studies pollen.

Teacher's Note:
1. Fossils give direct evidence of evolution.
2. They are dated by radioactive methods.

Answer: (c) homologous structures

Explanation:
1. Homologous structures have a common origin but different functions.
2. They show divergent evolution.

Teacher's Note:
1. Forelimbs of whales, bats and humans are homologous.
2. They show common ancestry.

Answer: (c) analogy

Explanation:
1. Both are used for swimming but have different origins.
2. They are analogous structures.

Teacher's Note:
1. Analogy shows convergent evolution.
2. Homology shows divergent evolution.

Answer: (d) camouflage

Explanation:
1. After industrialisation, dark moths were camouflaged on dark tree trunks.
2. Birds ate the white-winged moths.

Teacher's Note:
1. This shows natural selection in action.
2. Dark moths became more numerous.

Answer: (c) anthropogenic action

Explanation:
1. Human action such as drug use selects resistant forms.
2. This happens in a short time.

Teacher's Note:
1. Excessive use of pesticides has the same effect.
2. It is called evolution by anthropogenic action.

Answer: (a) Alfred Wallace

Explanation:
1. Alfred Wallace worked in the Malay Archipelago.
2. He reached the idea of natural selection independently.

Teacher's Note:
1. Wallace and Darwin published jointly.
2. Malthus influenced both.

Answer: (b) The rate of appearance of new forms is linked to the life cycle or life span

Explanation:
1. A short life cycle gives faster appearance of new forms.
2. Darwin said that adaptive ability is inherited, not acquired.

Teacher's Note:
1. The geological and biological histories correlate.
2. Natural selection can cause stabilisation, directional change or disruption.

Answer: (d) branching descent and natural selection

Explanation:
1. Branching descent means species arise from common ancestors.
2. Natural selection is the mechanism.

Teacher's Note:
1. Darwin used the word evolution only at the end.
2. He used descent with modification.

Answer: (d) Darwin

Explanation:
1. Malthus said that populations grow geometrically but food grows arithmetically.
2. This influenced Darwin's thinking.

Teacher's Note:
1. Struggle for existence follows from this idea.
2. Wallace was also influenced.

Answer: (a) Hardy-Weinberg principle

Explanation:
1. The gene pool remains constant if no evolution occurs.
2. The equation is p2 + 2pq + q2 = 1.

Teacher's Note:
1. Change in allele frequency means evolution.
2. The five factors that disturb it are gene flow, drift, mutation, recombination and selection.

Answer: (d) stabilisation, directional change or disruption

Explanation:
1. Stabilising selection favours the mean.
2. Directional selection shifts the peak and disruptive selection gives two peaks.

Teacher's Note:
1. Disruptive selection favours both extremes.
2. The middle forms decrease.

Answer: (d) extinct

Explanation:
1. Coelacanths were thought to be extinct.
2. They were rediscovered in South Africa.

Teacher's Note:
1. They are lobefins.
2. They gave rise to the first amphibians.

Answer: (b) lobefins

Explanation:
1. Lobefins had strong fins that could move on land.
2. They evolved into the first amphibians, which could live both on land and in water.

Teacher's Note:
1. The ancestral amphibians were Ichthyostega.
2. Amphibians gave rise to reptiles.

Answer: (c) 65

Explanation:
1. Dinosaurs disappeared about 65 mya.
2. They had ruled the earth for a long time before that.

Teacher's Note:
1. Mammals then spread.
2. The Mesozoic ended with their extinction.

Answer: (b) 15 mya

Explanation:
1. Dryopithecus and Ramapithecus lived about 15 mya.
2. They were hairy and walked like gorillas and chimpanzees.

Teacher's Note:
1. Ramapithecus was more man-like.
2. Dryopithecus was more ape-like.

Answer: (b) 650 to 800 cc

Explanation:
1. Homo habilis had 650 to 800 cc brain capacity.
2. It probably did not eat meat.

Teacher's Note:
1. Habilis was the first human-like being.
2. Erectus had 900 cc.

Answer: (a) Homo erectus

Explanation:
1. Homo erectus had about 900 cc brain capacity.
2. It probably ate meat.

Teacher's Note:
1. Erectus lived about 1.5 mya.
2. Fossils were found in Java.

Answer: (a) Neanderthal man

Explanation:
1. Neanderthals had 1400 cc brain.
2. They used hides to protect the body and buried their dead.

Teacher's Note:
1. Neanderthals had large brains.
2. They disappeared about 40,000 years ago.

Answer: (d) Africa

Explanation:
1. Homo sapiens arose in Africa.
2. They moved across continents and developed into distinct races.

Teacher's Note:
1. Modern man arose in Africa.
2. Pre-historic cave art appeared about 18,000 years ago.

Answer: (b) human brain and language

Explanation:
1. The story of man appears to parallel the evolution of the brain and language.
2. Language helped communication.

Teacher's Note:
1. Cave art shows the development of culture.
2. Art arose about 18,000 years ago.

Answer: (a) a-v, b-iv, c-i, d-ii

Explanation:
1. The last ice age was 75000 to 10000 years ago.
2. Cave art was 18000 years ago, Australopithecus lived in East African grasslands and ichthyosaurs were fish-like reptiles.

Teacher's Note:
1. Ichthyosaurs were marine reptiles.
2. They lived with dinosaurs.

Answer: (b) e-iii, f-vii, g-vi, h-x

Explanation:
1. The biggest dinosaur is Tyrannosaurus.
2. Homo erectus lived 1.5 mya, therapsids were mammal ancestors and the coelacanth is a lobefin.

Teacher's Note:
1. Tyrannosaurus was about 20 feet tall.
2. It had huge dagger-like teeth.