Which one of the following experiments suggests that simplest living organisms could not have originated spontaneously from nonliving matter?
Spallanzani’s experiment : He boiled the meat and vegetables for more than an hour to prepare broth and placed them in open and sealed flasks. The maggots of housefly developed in the open flasks but did not appear in sealed flasks. This disapproved the theory of spontaneous creation. (Th. of abiogenesis).
Which one of the following phenomena supports Darwin’s concept of natural selection in organic evolution?
When DDT was sprayed to kill mosquitoes, there were only few mosquitoes which were already resistant to DDT, and hence survived. Most of the mosquitoes which were sensitive to DDT died.
Due to differential reproduction the resistant mosquitoes got more chances of reproduction and multiplied. After few generations most of the mosquitoes were resistant. The sensitive were very few. This supports Darwin’s theory of natural selection and survival of the fittest.
Using imprints from a plate with complete medium and carrying bacterial colonies, you can select streptomycin resistant mutants and prove that such mutations do not originate as adaptation. These imprints need to be used
Adaptation is generally due to selection of pre-existing variations and not due to new mutations or variations. This tends to support Darwin’s theory of natural selection. The basis was proved by replica plating experiment of Joshua Lederberg and Esther Lederberg. A number of sterile agar plates having antibiotic streptomycin were prepared. Bacteria were inoculated on the renicilling plates from the master plate by sterile velvet plate. Most bacterial colonies did not form replicas and inoculum died. Moreover a few colonies survived showing that they were resistant to streptomycin.
de Vries gave his mutation theory on organic evolution while working on:
Pisum sativum - Mendel
Drosophila melanogaster - T. H. Morgan.
Which one of the following amino - acid was not found to be synthesized in Miller's experiment ?
Glutamic Acid is one of the non-essential amino acids, closely related to glutamine. The two constitute a substantial fraction of the amino acids in many proteins (10–20% in many cases and up to 45% in some plant proteins). An important metabolic intermediate as well as a neurotransmitter molecule in the central nervous system, glutamic acid finds uses in medicine and biochemical research. Its sodium salt is the food flavour enhancer monosodium glutamate (MSG).
Jurassic period of the mesozoic era was characterised by
Jurassic period of meoszoic era was about 19-20 crore years ago & lasted for about 5.5-6 crore years. The climate was hot and damp. It is called the age of dinosaurs. Ist primitive bird Archaeopteryx evolved from reptiles. Ist angiosperm appeared as a dicotyledon but gymnosperms were dominant.
Evolutionary history of an organism is known as
Paleontolog y is the study of fossils. Ontogeny is the process of development of organism in the embryo stage and phylogeny is known as the history of an organism through ages during evolution.
An important evidence in favour of organic evolution is the occurrence of
Homologous organs represent the divergent evolution. These are the organs belonging to different organisms of different species may be for dissimilar function but they all have the same basic structure. On the other hand vestigial organs show that how a species evolved from its ancestors through the ages according to the use and disuse of organs. These are the organs which were sometime functional in humans (or may be any other organisms) but during the course of evolution their utility gradually decline and now they are present as nonfunctional and vestigial organs.
Which one of the following is not a living fossil?
Archaeopteryx is a fossile (dead) found from the mesozoic rocks. It is a connecting link between reptiles and birds.
When two species of different genealog y come to resemble each other as a result of adaptation, the phenomenon is termed
The analogous organs show convergent evolution due to similar adaptions which do not support organic evolution.
Among the human ancestors the brain size was more that 1000 cc in
Homo habilis had a cranial capacity in the range of 680 - 720 c.c & that of . Homo erectus erectus 775 - 990 c.c., Homo erectus pekinesis 915-1200 c.c. Homo nenderthalensis 1300-1600 c.c.
Which one of the following statement is correct?
Ontogeny repeats phylogeny.
The concept of chemical evolution is based on
The concept of chemical evolution is based on possible origin of life by combination of chemicals under suitable environmental conditions. The distribution of elements in the cosmos is the result of many processes in the history of the Universe. It provides us with a powerful tool to study the Big Bang, the density of baryonic matter, nucleosynthesis and the formation and evolution of stars and galaxies.
The finches of Galapagos islands provide an evidence in favour of
The finches of Galapagos islands provides an evidence in favour of biogeographical evolution
What is common between parrot, platypus and kangaroo?
Only birds and mammals are homeothermous.
Which one of the following is a matching pair of a body feature and the animal possessing it ?
Leech has ventral central nervous system which consists of nerve ring, and a solid, double, mid ventral nerve cord with ganglia.
What is common to whale, seal and shark?
The analogous organs show convergent evolution due to similar adaptation. They do not support organic evolution. Whale, seal and shark shows convergent evolution due to similar habitats.
Industrial melanism as observed in peppered moth proves that
During the period when the number of coal-burning factories in England was increasing (during the so-called Industrial Revolution) it was noticed that the number of melanic individuals of the species of Peppered Moth (Biston betularia) was becoming more common. Originally rare in the population of normally light-colored moths, the frequency of the melanic form increased in polluted areas until it was over 90%. This change in color has come to be known as "industrial melanism."
Adaptive radiation refers to
Adaptive radiation refers to evolution of different species from a common ancestor. The mammals are adapted for different mode of life i.e. they show adaptive radiation. They can be aerial (bat), aquatic (whale and dolphins), burrowing or fossorial (rat), cursorial ( horse), scantorial (squarrel) or arboreal (monkey). The adaptive radiation, the term by osborn, is also known as Divergent evolution.
One of the important consequences of geographical isolation is
Speciation takes place via reproductive isolation which is the most important consequence of geographical isolation.
Which one of the following in birds, indicates their reptilian ancestry?
Scales on their hind limbs and eggs with calcareous shell, indicates in birds about their reptilian ancestry.
Darwinism finches are an excellent example of
Darwin's Finches are an excellent example of adaptive radiation. Adaptive radiation is the occurrence of the diversification of a single or small groups of species into a large number or descendents that occupy various ecological niches. This is an evolutionary process driven by natural selection.
Thorn of Bougainvillea and tendril of cucurbita are example of
Thorn of Bougainvillea and tendril of Cucurbita are example of homologous chromosomes.
Which one of the following pairs of items correctly belongs to the category of organs mentioned against it?
Nephridia of earthworm and malphigian tubules of cockroch belongs to excretory organs. Earthworm has a well developed excretory system which is composed of large number of minute, coiled and glandular segmentally arranged excretory tubules called the nephridia. Malphigian tubules of cockroach are extremely fine yellowish unbranched thread like structure present at the function of midgut and hindgut.
Which one of the following is incorrect about the characteristics of protobionts (coacervates and microspheres) as envisaged in the biogenic origin of life?
Coacervate is an aggregate of macromolecules such as proteins, lipids and membrane and contain enzymes that are capable of converting such substance as glucose into more complex molecules, such as starch. Coacervate droplets arise spontaneously under appropriate conditions and may have been the prebiological systems from which living organisms originated.