In Miller's experiment, he used a mixture of CH4, NH3, H2 and water vapour in a closed flask to mimic early earth conditions. What was the temperature at which this flask was kept?
Which of the following is reptilian ancestor of birds?
The correct sequence of stages in the evolution of modern man (Homo sapiens), is
(1) Homo erectus, Australopithecus, neanderthal man, cro-magnon man, modern man
(2) Australopithecus, Homo erectus, neanderthal man, cro-magnon man, modern man
(3) neanderthal man, Australopithecus, cro-magnon man, Homo erectus, modern man
(4) Australopithecus, neanderthal man, cro-magnon, Homo erectus, modern man
Documented microfossils have been found that are as old as
(1) 2.5 billion years
(2) 3.5 billion years
(3) 1.5 billion years
(4) 2.5 billion years
From the statements given below, which one most likely represents an example of disruptive selection.
I. Industrial melanism in peppered moth.
II. Population of butterflies that are either all yellow or all blue.
III. Population of rabits that evolves more body fat in response to a cold climate.
IV. Population of wrens that evolves to be smaller at sexual maturity in response to predation pressure.
V. Very tall and very short pine trees being removed from a population by herbivorey.
(1) Only II
(2) II and III
(3) Only IV
(4) III and IV
The best description of natural selection is
(1) the survival of the fittest
(2) the struggle for existence
(3) the reproductive success of the members of a population best adapted to the environment
(4) a change in the proportion of variation within a population
Reproduction isolation in sympatric speciation develops without a
(1) Geographic barrier
(2) Barrier to gene flow
(3) Change in chromosome number
(4) Barrier to mating
Which of the following sets do not have homologous organs?
(1) Mouth parts of cockroach and butterfly
(2) Wings of butterfly and bird
(3) Wings of mosquito and butterfly
(4) Forelegs of horse and paddles of whale
Which of the following is the relatively most accurate method for dating fossils?
(1) Pottasium-argon method
(2) Uranium-lead method
(3) Electron-spin resonance method
(4) Radio-carbon method
At a particular locus, frequency of 'A' allele is 0.6 and that of 'a' is 0.4. What would be the frequency of heterozygotes in a randomly mating population of equilibrium ?