54478.Viviparity is considered to be more evolved because
the young ones are left on their own
the young Ones are protected by a thicks shell
the young ones are protected inside the mothers body and are looked after they are born leading to more chances of survival
the embryo takes a long time to develop
Explanation:
Viviparity is considered to be more evolved because the young’s ones are protected inside the mother s body and are looked after once they are born, leading to more chances of survival, e.g., mammals.However, in oviparity, the female lays fertilised/unfertilised eggs covered by a hard calcareous shell in a safe place in the environment. The chances of survival are less as the young ones are left on their own.
Viviparity is considered to be more evolved because the young’s ones are protected inside the mother s body and are looked after once they are born, leading to more chances of survival, e.g., mammals.However, in oviparity, the female lays fertilised/unfertilised eggs covered by a hard calcareous shell in a safe place in the environment. The chances of survival are less as the young ones are left on their own.
54479.Which type of selection is industrial melanism observed in moth, Biston betularia
Stabilising
Directional
Disruptive
Artificial
Explanation:
The industrial melanism is a type of directional selection observed in moth. Under this,individuals at one end of the frequency distribution do well light and so more individuals of that type will be present in next generation.The other options are incorrect because in stabilising selection, average sized individuals are favoured, e.g., weight of new-born babies and in disruptive selection both extremes are favoured, while intermediate varieties are elemmated.e.g., black bellied seed cracker, Pyrenestes ostrinus.In artificial selection, the individuals with desirable characteristics are deliberately selected to produce a progeny with all those characteristics.
The industrial melanism is a type of directional selection observed in moth. Under this,individuals at one end of the frequency distribution do well light and so more individuals of that type will be present in next generation.The other options are incorrect because in stabilising selection, average sized individuals are favoured, e.g., weight of new-born babies and in disruptive selection both extremes are favoured, while intermediate varieties are elemmated.e.g., black bellied seed cracker, Pyrenestes ostrinus.In artificial selection, the individuals with desirable characteristics are deliberately selected to produce a progeny with all those characteristics.
54480.Fossils are generally found in
sedimentary rocks
igneous rocks
metamorphic rocks
any type of rock
Explanation:
Fossils are generally found in sedimentary rocks,-which are formed by the gradual deposition of silt, sand or calcium carbonate over millions of years in regions such as lakes or sea during their formation, the dead animals flow down into the sea or large lake, sink down and get burriedin the rocks. The animals, thus preserved in the rocks, are converted into fossils.Igneous rocks are formed from lava and hence no fossil can be found in them. Metamorphic rocks can be made from igneous or sedimentary rocks
Fossils are generally found in sedimentary rocks,-which are formed by the gradual deposition of silt, sand or calcium carbonate over millions of years in regions such as lakes or sea during their formation, the dead animals flow down into the sea or large lake, sink down and get burriedin the rocks. The animals, thus preserved in the rocks, are converted into fossils.Igneous rocks are formed from lava and hence no fossil can be found in them. Metamorphic rocks can be made from igneous or sedimentary rocks
54481.For the MN-blood group system, the frequencies of M and N alleles are 0.7 and 0.3, respectively. The expected frequency of MN-blood group bearing organisms is Likely to be
42%
49%
9%
58%
Explanation:
According to Hardy-Weinberg equation, p2+ 2pq + q2=1
where, p= Frequency of M alleles,
p2= Frequency of homozygous dominant individuals.
q = frequency of N alleles
q2= Frequency of homozygous recessive individuals
2pq = Frequency of heterozygous individuals.
So, (0.7)2+ (0.3)2+ 2 pq = 1
0.49+ 0.09+ 2 pq = 1
2pq = 0.42
Thus, frequency of heterozygous individuals i.e., 42%
According to Hardy-Weinberg equation, p2+ 2pq + q2=1
where, p= Frequency of M alleles,
p2= Frequency of homozygous dominant individuals.
q = frequency of N alleles
q2= Frequency of homozygous recessive individuals
2pq = Frequency of heterozygous individuals.
So, (0.7)2+ (0.3)2+ 2 pq = 1
0.49+ 0.09+ 2 pq = 1
2pq = 0.42
Thus, frequency of heterozygous individuals i.e., 42%
54482.The amino acid attaches to the tRNA at its
5-end
3-end
Anticodon site
DHU loop
Explanation:
AA-binding site (amino acid binding site) lies at the 3 end opposite the anticodon and has CCA-OH group. Itis the site where amino acid attaches to the tRNA.
AA-binding site (amino acid binding site) lies at the 3 end opposite the anticodon and has CCA-OH group. Itis the site where amino acid attaches to the tRNA.
54483.Evolution of Life shows that Life forms had a trend of moving from
land to water
dryland to wet land
freshwater to sea water
water to land
Explanation:
Evolution of life shows that life forms had a trend of moving from water to land. The early vertebrates were fishes (which lived in only water). Some fishes gradually changed into amphibians (can live both on land and in water).Certain amphibians then transformed into the reptiles (live on land) some of the latter finally evolved into birds (can fly) and then mammals. Thus, showing life forms moved from water to land.
Evolution of life shows that life forms had a trend of moving from water to land. The early vertebrates were fishes (which lived in only water). Some fishes gradually changed into amphibians (can live both on land and in water).Certain amphibians then transformed into the reptiles (live on land) some of the latter finally evolved into birds (can fly) and then mammals. Thus, showing life forms moved from water to land.
54484.Which of the following is an example for link species?
Lobe fish
Dodo bird
Sea weed
Chimpanzee
Explanation:
Lobe fish shows characters from cartilaginous fishes and from amphibia. They belong to bony fishes. Since, they show characters from two other groups of animals, they are considered as link species
Lobe fish shows characters from cartilaginous fishes and from amphibia. They belong to bony fishes. Since, they show characters from two other groups of animals, they are considered as link species
54485.Variations during mutations of meiotic recombinations are
random and directionless
random and directional
random and small
random, small and directional
Explanation:
Variations during mutations of meiotic recombination are random and directionless. Hugo de Vries based on his work on evening primrose stated that it is mutation which causes sudden appearance of variations that results in speciation.He stated that mutations are sudden, heritable and persistent in successive generation. He contradicted Darwinian variations that are small and directional.
Variations during mutations of meiotic recombination are random and directionless. Hugo de Vries based on his work on evening primrose stated that it is mutation which causes sudden appearance of variations that results in speciation.He stated that mutations are sudden, heritable and persistent in successive generation. He contradicted Darwinian variations that are small and directional.
54486.To initiate translation, the mRNA first binds to
the smaller ribosomal sub-unit
the larger ribosomal sub-unit
the whole ribosome
No such specificity exists
Explanation:
The ribosome consists of structural RNAs and about 80 different proteins. In its inactive state, it exist as two subunits, a large subunit and a small subunit. When the smaller subunit encounters the mRNA, the process of translation of the mRNA to protein begins
The ribosome consists of structural RNAs and about 80 different proteins. In its inactive state, it exist as two subunits, a large subunit and a small subunit. When the smaller subunit encounters the mRNA, the process of translation of the mRNA to protein begins
54487.Analogous organs arise due to
divergent evolution
artificial selection
genetic drift
convergent evolution
Explanation:
Analogous organs arise due to convergent evolution. These are the organs which have similar functions, but are different in their structural details and origin, e.g., wings of insectand bird.The other three options are incorrect, because divergent evolution gives rise to homologous organs, genetic drift can contribute to speciation and artificial selection is used to produce improved varieties of animals and plants.
Analogous organs arise due to convergent evolution. These are the organs which have similar functions, but are different in their structural details and origin, e.g., wings of insectand bird.The other three options are incorrect, because divergent evolution gives rise to homologous organs, genetic drift can contribute to speciation and artificial selection is used to produce improved varieties of animals and plants.
54488.Appearance of antibiotic-resistant bacteria is an example of
adaptive radiation
transduction
pre-existing variation in the population
divergent evolution
Explanation:
Appearance of antibiotic-resistant bacteria is an example of pre-existing variation in the population. When a bacterial population encounters a particular antibiotic, those sensitive to it die.But some bacteria having mutations become resistant to the antibiotic. Soon, the resistance providing genes become widespread and the entire population becomes resistant.Adaptive radiation is development of different functional structures from a common ancestral form which is also known as divergent evolution.Transduction is a process whereby, foreign DNA is introduced into another cell via a viral vector.Divergent evolution gives rise to homologous organs.
Appearance of antibiotic-resistant bacteria is an example of pre-existing variation in the population. When a bacterial population encounters a particular antibiotic, those sensitive to it die.But some bacteria having mutations become resistant to the antibiotic. Soon, the resistance providing genes become widespread and the entire population becomes resistant.Adaptive radiation is development of different functional structures from a common ancestral form which is also known as divergent evolution.Transduction is a process whereby, foreign DNA is introduced into another cell via a viral vector.Divergent evolution gives rise to homologous organs.
54489.Animal husbandry and plant breeding programmes are the examples of
reverse evolution
artificial selection
mutation
natural selection
Explanation:
These are examples of artificial selection Artificial selection is a process of breeding of plants and animals to produce desirable traits. The other three options are incorrect as mutation is a sudden change in DNA sequence due to mutagenic agents such as cherncals and radiations.Natural selectionis a gradual process by which biological traits become either more or less common in a population as a function of the effect of the changing environment.Reverse evolutionor devolution is a notion that species can change into more primitive forms over time.
These are examples of artificial selection Artificial selection is a process of breeding of plants and animals to produce desirable traits. The other three options are incorrect as mutation is a sudden change in DNA sequence due to mutagenic agents such as cherncals and radiations.Natural selectionis a gradual process by which biological traits become either more or less common in a population as a function of the effect of the changing environment.Reverse evolutionor devolution is a notion that species can change into more primitive forms over time.
54490.In 1953 SL Miller created primitive earth conditions in the laboratory and gave experimental evidence for origin of first form of life from pre-existing non-living organic molecules. The primitive earth conditions created include
low temperature, volcanic storms, atmosphere rich in oxygen
low temperature, volcanic storms, reducing atmosphere
high temperature, volcanic storms, non-reducing atmosphere
high temperature, volcanic storms, reducing atmosphere containing CH4, NH3 etc.
Explanation:
The Miller -Urey experiment tested for the occurrence of chemical evolution by stimulating hypothetical conditions present on early earth.These primitive earth conditions include high temperature, volcan strom and reducing environment containing methane (CH4), ammonia (NH3), hydrogen (H2) and water (H2O).They ultimately found that a large number of simple organic compounds reducing some amino acids such as alanine, glycine and aspartic acid can be synthesized in into as during chemical origin of life.
The Miller -Urey experiment tested for the occurrence of chemical evolution by stimulating hypothetical conditions present on early earth.These primitive earth conditions include high temperature, volcan strom and reducing environment containing methane (CH4), ammonia (NH3), hydrogen (H2) and water (H2O).They ultimately found that a large number of simple organic compounds reducing some amino acids such as alanine, glycine and aspartic acid can be synthesized in into as during chemical origin of life.
54491.The theory of spontaneous generation stated that
life arose from living forms only
life can arise from both living and non-living
life can arise from non-living things only
life arises spontaneously, neither from living norfrom the non-living.
Explanation:
The theory of spontaneous generation stated that an obsoletetheorythat states that living organisms can originate from inanimate (non-living) objects. It is also known as abiogenesis.
The theory of spontaneous generation stated that an obsoletetheorythat states that living organisms can originate from inanimate (non-living) objects. It is also known as abiogenesis.
54492.Which of the following is used as an-atmospheric pollution indicator?
Lepidoptera
Lichens
Lycopersicon
Lycopodium
Explanation:
Lichens can be used as an atmospheric pollution indicator. They do not grow in areas that are polluted, as they are sensitive (especially phycobiont) to oxides of nitrogen and sulphur, hence unable to synthesise organic food and do not grow well.
Lichens can be used as an atmospheric pollution indicator. They do not grow in areas that are polluted, as they are sensitive (especially phycobiont) to oxides of nitrogen and sulphur, hence unable to synthesise organic food and do not grow well.
54493.The bones of forelimbs of whale, bat, cheetah and man are similar in structure, because
one organism has given rise to another
they share a common ancestor
they perform the same function
theyhave biochemical similarities
Explanation:
The bones of forelimbs of whale, bat, cheetah and man are similar in structure, because they have a common ancestor.These are homologous organs which have different functions across diverse forms, but are developed along same pattern. These organs arise due to divergent evolution.
The bones of forelimbs of whale, bat, cheetah and man are similar in structure, because they have a common ancestor.These are homologous organs which have different functions across diverse forms, but are developed along same pattern. These organs arise due to divergent evolution.
54494.The most accepted line of descent in human evolution is
Australopithecus →Ramapithecus →Homo sapiens → Homo habilis
Homo erectus → Homo habilis→ Homo sapiens
Ramapithecus→ Homo habilis→ Homo sapiens
Australopithecus →Ramapithecus→ Homo erectus →Homo habilis →Homo sapiens
Explanation:
Ramapithecus:Survived about 14-15 mya, walked erect on its hind legs
Homo habilis:Did not eat meat, brain capacity 650-800 cc, lived about 1.5 mya
Homo sapiens: Erect posture and limbs straight, brain capac 1450 cc.
Ramapithecus:Survived about 14-15 mya, walked erect on its hind legs
Homo habilis:Did not eat meat, brain capacity 650-800 cc, lived about 1.5 mya
Homo sapiens: Erect posture and limbs straight, brain capac 1450 cc.
54495.In E. coli, the lac operon gets switched on when
lactose is present and it binds to the repressor
repressor binds to operator
RNA polymerase binds to the operator
lactose is present and it binds to RNA polymerase
Explanation:
In case of lactose presence
(i) Lactose acts as an inducer which binds to the repressor and forms an inactive repressor.
(ii) The repressor fails to bind to the operator region.
(iii) The RNA polymerase binds to the operator and transcript lac mRNA.
(iv) lac mRNA is polycistronic, i.e., produces all three enzymes, (β-galactosidase, permease and transacetylase.
(v) The lac operon is switched on.
In case of lactose presence
(i) Lactose acts as an inducer which binds to the repressor and forms an inactive repressor.
(ii) The repressor fails to bind to the operator region.
(iii) The RNA polymerase binds to the operator and transcript lac mRNA.
(iv) lac mRNA is polycistronic, i.e., produces all three enzymes, (β-galactosidase, permease and transacetylase.
(v) The lac operon is switched on.
54496.(p + q)2= p2+ 2pq+ p2=1, represents an equation used in
population genetics
Mendelian genetics
biometrics
molecular genetics
Explanation:
(p + q)2= p2+ 2pq +q2= 1 represents an equation used in population genetics.It is a mathematical representation of Hardy-Weinberg principle . This principle says that allele frequencies in a population are stable and are constant from generation to generation, i.e., the gene pool remains constant.
(p + q)2= p2+ 2pq +q2= 1 represents an equation used in population genetics.It is a mathematical representation of Hardy-Weinberg principle . This principle says that allele frequencies in a population are stable and are constant from generation to generation, i.e., the gene pool remains constant.
54497.Palaeontological evidences for evolution refer to the
development of embryo
homologous organs
fossils
analogous organs
Explanation:
Palaeontological evidences for evolution refer to the evidences from fossils. Fossils are the preserved remains or traces of organisms from the distant past. The study of fossils is called Palaeontology. The other options are not correct because the development patterns of embryo refer to embryological evidences for evolution.Homologous and analogous organs provide evidences for comparative anatomy and morphology.
Palaeontological evidences for evolution refer to the evidences from fossils. Fossils are the preserved remains or traces of organisms from the distant past. The study of fossils is called Palaeontology. The other options are not correct because the development patterns of embryo refer to embryological evidences for evolution.Homologous and analogous organs provide evidences for comparative anatomy and morphology.