In Down’s syndrome of a male child, the sex complement is
Which of the following is nota part of Darwin’s theory of evolution?
According to special creation theory the earth is about
The two strands of DNA are held together by
Who proved that DNA is basic genetic material?
The factors which represent the contrasting pairs of characters are called
What was the most significant trend in evolution of modern man (Homo sapiens) from his ancestors ?
The most significant trend in evolution of modern man(Homo sapiens) from his ancestors is development of brain capacity.
The first organisms were
Chemoheterotrophs were first organisms. They wereprokaryotic like bacteria, anaerobes, as molecular oxygen was absent. They obtained energy by fermentation of some of the organic molecules presentin the broth. Thus they absorbed organic molecules from outside for body building and energy.
•Chemoautotrophs - Organisms that are capable to synthesize organic molecules from inorganic molecules.E.g., Nitrifying bacteria, sulphur reducing bacteria etc.
•Autotrophs are photosynthesizing plants/organisms.
Genetic variation in a population arises due to
Crossing over leads to recombination of genetic material on the two chromosomes. Mutation results in alternation of DNA sequences and consequently results in change in the genotype and the phenotype of an organism. In addition to recombination, mutation is another phenomenon that leads to variation in DNA.
Which one is linked to evolution?
Organic evolution is process of cumulative change of living populations and in the descendant populations of organisms. According to Darwin, variations are differences among in dividuals. Variations which help the individual to fitin its surroundings are passed onto the next generation while others disappear. Thus,variation plays an important role inevolution