BIOLOGY MCQ

Random mating.

Biogeography

Recapitulation

Neanderthal human.

Gymnosperms are dominant plants and first birds appear.

Weismann

Arm and leg of man and horse are examples of homologous organs. A homologous structure is an example of an organ or bone that appears in different animals, underlining anatomical commonalities demonstrating descent from a common ancestor.
In other words, its when very different animals have bones that appear very similar in form or function and seem to be related. So, we can say there is a phylogenetic relationship between man and horse.

Animal husbandry and plant breeding programmes need human intervention and desirable characters are introduced in plants and animals through manipulation. Hence, these are examples of artificial selection.

During human evolution, several species and subspecies roamed on earth and lived together and also possibly exchanged genes, thus, obscuring the exact lineage which ultimately evolved into modern humans, but Homo erectus that lived around middle Pleistocene, are thought of as the direct line that evolved into modern man. The most important subspecies of Homo erectus are Java man, Peking man and Heidelberg man.

A small population is not in Hardy Weinberg Equilibrium and may lose alleles due to Genetic Drift.

Eobionts are hypothetical primordial life-form or chemical precursor to a living organism. The coacervates got transformed into the primitive living systems, which have been called as, protobionts or eobionts.
These are the first formed cells. So, called as, pre cells or protocells or protobionts.

Banding pattern in chromosomes number 3 and 6.

Random and directionless.

Fossils.

Africa

Saltation.

Directional as it pushes the mean of the character in one direction.

Population genetics.

Haldane

Loss of tail.

In evolutionary biology, adaptive radiation is a process in which organisms diversify rapidly from an ancestral species into a multitude of new forms, particularly when a change in the environment makes new resources available, creates new challenges, or opens new environmental niches.
Hence, Adaptation is a type of Adaptive radiation.

They are uniparental in origin and do not take part in recombination.

Lamarck

The animals or plants that evolve same structure along different directions due to adaptations to different needs is known as divergent or homologous evolution and it shows common ancestry. The thorn and tendrils of Bougainvillea and Cucurbita represent homology.

How life actually originated we do not know but we do know that it started with accumulation of biomolecules produced in reducing atmosphere. The biomolecules later on gave rise to aggregates of biomolecules.
First nucleoproteins were most probably produced on clay surfaces. That was the important first sign of life because it meant a transition from an aggregate of biomolecule to a self replicating entity, an important characteristic of living organisms.

According to special creation theory, all the different forms of life that occur today on planet earth, have been created by God, the almighty. This idea is found in the ancient scriptures of almost every religion. According to Hindu mythology, Lord Brahma, the God of Creation, created the living world in accordance to his wish.
According to the Christian belief, God created this universe, plants, animals and human beings in about six natural days. The Sikh mythology says that all forms of life including human beings came into being with a single word of God. Special creation theory believes that the things have not undergone any significant change since their creation.

Similarity in structural design indicates towards a common ancestry.

Adaptive convergence of closely related groups.

Fitness is the end result of the ability to adapt and get selected by nature.

Convergent evolution means distantly related groups have different forms of structures or adaptation for performing similar functions.

Archaeopteryx, intermediate between reptiles and birds, originated towards the close of Jurassic period.

Discontinuous variations.

First cells produced were simple aggregates of organic compounds, called protobionts, which are thought to be precursors of prokaryotes.

They share a common ancestor.