Biology 1 Marks Question

Alfred Wallace. He worked in Malay Archepelago.

Fossils are the remnants and/ or impressions of the life-forms that lived in the remote past.

Jurassic period of mesozoic era.

Two key concepts of Darwinism are:

1. Branching descent.
2. Natural selection.

Analogous as these are functionally similar but anatomically different.

Triassic.

2000 million years ago.

Lobefins were ancestors of evolution as their discovery evolved amphibians and fish-like organisms.

Stanley Miller and Urey.

Ramapithecus.

A sudden change in gene frequency by chance alone rather than by natural selection is called genetic drift.

When a section of population migrates, it results in addition of new genes or alleles to one population and their loss to another population. This is called gene migration.

When two species which are closely related show convergent evolution, it is called parallel evolution.

By radiocarbon dating.

Saltation refers to single-step large mutation that results in speciation.

It is the principle which states that gene frequency in a population remains stable and constant from generation to generation.

Pre-existing varations are the most important pre-condition for adaptive radiation.

According to this theory living organisms arose from decaying and rotting matter.

Dryopithecus.

It refers to the similarity of structural design, anatomy and embryology of organs of different groups of plants and animals.

The Big Bang theory.

Stanley Miller and Harold Urey.

Wings of butterfly.

According to Hardy-Weinberg, the disturbance in genetic equilibrium is the result of evolution.

1. Presence of free oxygen in present day atmosphere.
2. Existence of living organisms.

Sometimes the change in allele frequency is so different in the new sample of population that they become a different species. The original drifted population becomes founder and the effect is called founder effect.

Oparin-Haldane theory.

Carboniferous period of paleozoic era.

Mutation.

Oparin and Haldane.

The first mammals were like shrews.

Fossilised life forms had some hard parts which could be preserved between layers of rocks.

Mutations are:

1. Random.
2. Directionless.

Evolutionary Biology is the study of history of life forms on earth.

Greenland rocks.

Spotted cuscus - Lemur
Tasmanian tiger cat - Bobcat

Mutation.