Evolution Test 5

Jurassic period of Mesozoic era characterized presence of Gymnosperms as dominant plant and first birds evolved from reptiles. Dianasours are also a kind of reptiles.

The organic compounds first evolved in earth required for origin of life were proteins and nucleic acids. Proteins are made of amino acids arranged in different order and DNA and RNA are nucleic acids.

Jean Baptiste Van Helmont carried out an experiment to show the production of mice in 21 days from a dirty shirt placed in contact with kernels of wheat to prove that life originated form inorganic substance.

An organism that lays 5 eggs, hatch the 5 eggs to reproduce 5 offspring can be considered as most evolved out of the other given condition. Least evolved organism lays more egg but produce only a few offspring.

Analogous organs are those organs which have the same function but are quite different in their fundamental structure and embryonic origin. For example, the wing of an insect and the wing of a bird are analogous organs. Both these organs are used for flying in the air but they re very different in structure. An insect wing is an extension of the integument whereas a bird wing is formed of limb bones covered with flesh, skin, and feathers. Each has evolved from a separate ancestral population as a means of a more efficient mode of locomotion. Similarity developed in distantly related groups as an adaptation for the same function is called analogy or convergent evolution.

Thus, the correct answer is option B. 

The correct option is Option B.

A protobiont is an aggregate of abiotically produced organic molecules surrounded by a membrane or a membrane-like structure. Protobionts exhibit some of the properties associated with life, including simple reproduction, metabolism and excitability, as well as the maintenance of an internal chemical environment different from that of their surroundings. It has been suggested that they are a key step in the origin of life on earth. Experiments by Sidney W. Fox and Aleksandr Oparin have demonstrated that they may be formed spontaneously, in conditions similar to the environment thought to exist on an early Earth.

Protobionts are excitable, metabolically active, inaccurately reproducing protein clusters. These clusters form when their protein parts are mixed with cold water: they self-assemble into microspheres. Protobionts also can release voltage like a neuron because some protobionts store energy through a similar method of membrane potential as organelles. If coated with a semipermeable membrane, a protobiont will swell and contract osmotically when in solutions of differing salt concentrations. The protobiont shares its weak catabolic capabilities with the liposome. They were partially isolated from the environment, but they could not separate combinations of molecules from the surroundings. Other statements are correct and only option B is incorrect.

There are many evidences that favor the organic evolution of life. According to this concept life originate from pre-existing organisms by evolution in cousr of time. Homologous and vestigial organs hit the uses of different organs in different organism for different purpose.

The earliest organisms that appeared on the earth were non-green and presumably anaerobes. The first autotrophic organisms were the chemo-autotrophs that never released oxygen. Both the statements are correct but reason does not explain the assertion.

According to Neo-Darwinism, natural selection operates through differential reproduction. During sexual reproduction gametes are formed by meiosis division in which crossing over brings about change in traits that leads to variation for natural selection.

Vermiform appendix in man, nictitating membrane and wisdom teeth are vestigial organs of human beings. These organs are functional in our ancestors but in present human beings they have become functionless and only present as remain.

The geographical region Palarctic and Oriental are separated by high mountain ranges. The geographical separation do not allow the gene flow as mating is not possible between member of species.

amount of uranium present

Natural selection is the survival of members of species having some new traits that may help the organism in given surrounding. Sexual selection is a kind of natural selection as mating between similar organisms only leads to reproduction.

Palaeritological evidences for evolution refer to the fossils. Fossils provide direct and solid evidence in favour of organic evolution through ages. Fossils are studied for knowing about extinct organisms. Birbal Sahni Institute of Palaeobotany is situated at Lucknow. Birbal Sahni is called ‘Father of Indian Palaeobotany’. Age of fossils is determined by Uranium-Lead method (U²³⁸) or Potassium-Argon method or Radioactive Carbon dating (C¹⁴). ESR (electron-spin-resonance method) is the most accurate method of dating of fossils.

The Hardy-Weinberg principle states that allelic and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences. There are five factors which are known to affect the equilibrium. These are gene flow, genetic drift, mutation, genetic recombination and natural selection. In population genetics, gene flow (also known as gene migration) is the transfer of alleles or genes from one population to another. Migration into or out of a population may be responsible for a marked change in allele frequencies (the proportion of members carrying a particular variant of a gene). Genetic drift (also known as allelic drift) is the change in the frequency of a gene variant (allele) in a population due to chance events. Genetic recombination is the production of offspring with combinations of traits that differ from those found in either parent. Mutation causes variations in the species, which influences the gene pool. Natural selection favours certain variations over others, resulting in an increase in allelic frequency of the favourable variations in the gene pool. Reproduction is a natural process in all organisms, which as such, does not affect Hardy-Weinberg equilibrium; it would be the genetic recombinations that arise from sexual reproduction, that affect it.

Darwin finches and Australian marsupials are example of adaptive radiations as all the birds evolve from same birds having different beaks and Australian marsupials arise from common ancestors.

Wolf and Tasmania Wolf are examples of convergent evolution of placental mammals and Australian marsupials. They are evolved differently due to different in climatic and geographic regions.

When more than one adaptive radiation appeared in isolated geographical area it called a convergent evolution. Tiger cat, kangaroo, wombat and sugar gliders are example of Australian marsupials.

Homo sapiens arose in Africa and moved across continents and developed into distinct races during ice age between 75000-10000 years ago modern Homo sapiens arose.

Human settlement started around 10, 000 years ago due to starting of agriculture. After starting of agriculture, the human civilization started the grows and decline many times.

Common origin of man and chimpanzee is best shown by chromosomes. Both human beings and chimpanzee shows similar kinds of chromosome in terms of number and size.

Pre-historic man who gave proper burial to the dead for the first time was Neanderthal man of brain size 1400 cc lived in near east and central Asia about 100000 –40000 years back.

Among primates Chimpanzee is closet relative to the present day humans.The banding pattern of autosomes 3 and 6 of humans and Chimpanzee is remarkably similar.

Homo habilis were first man like creatures. Homo erectus arose about 1.5 Maya ago and present human beings, Homo sapiens arose in Africa during ice age.

Evolution of modern man is most interesting and appears parallel evolution of human brain and language. Homo habilis have brain size 650cc-800cc that evolved to 1400cc in Homo sapiens.