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Free download in PDF CBSE Class 12 Biology MCQs & Answers. Here Gkseries provide Biology Solve Questions and Answers for CBSE Class 12 Students.
81
Anti venom against snake poison contains
[A]
antigens
[B]
antigen-antibody complexes
[C]
antibodies
[D]
enzymes
82
The disease chikungunya is transmitted by
[A]
houseflies
[B]
cockroach
[C]
Aedes mosquitoes
[D]
female Anopheles
83
Opium is extracted from
[A]
Papaver somniferum
[B]
Cannabis sativa
[C]
Atropa belladona
[D]
Erythroxylum coca
Answer: Papaver somniferum
84
Diacetyl morphine is commonly known as
[A]
heroin
[B]
cocaine
[C]
hashish
[D]
ganja
85
The immunoglobulin abundant in colostrum, is
[A]
Ig A
[B]
Ig M
[C]
Ig D
[D]
Ig G
86
The letter T in T-lymphocytes refers to
[A]
thymus
[B]
thyroid
[C]
tonsil
[D]
thalamus
87
In the immune system, interferons are a part of
[A]
cytokine barriers.
[B]
physical barriers
[C]
physiological barriers
[D]
cellular barriers
Answer: cytokine barriers.
88
The most accepted line of descent in human evolution is [NCERT Exemplar]
[A]
Australopithecus → Ramapithecus → Homo sapiens → Homo habilis
[B]
Homo erectus → Homo habilis → Homo sapiens
[C]
Ramapithecus → Homo habilis → Homo erectus → Homo sapiens
[D]
Australopithecus → Ramapithecus → Homo erectus → Homo habilis → Homo sapiens.
Answer: Ramapithecus → Homo habilis → Homo erectus → Homo sapiens
89
In 1953 S. L. Miller created primitive earth conditions in the laboratory and gave experimental evidence for origin of first form of life from preexisting non-living organic s molecules. The primitive earth conditions created include [NCERT Exemplar]
[A]
low temperature, volcanic storms, atmosphere rich in oxygen
[B]
low temperature, volcanic storms, reducing atmosphere
[C]
high temperature, volcanic storms, non¬reducing atmosphere
[D]
high temperature, volcanic storms, reducing atmosphere containing CH4, NH3 etc.
Answer: high temperature, volcanic storms, reducing atmosphere containing CH4, NH3 etc.
90
Appearance of antibiotic-resistant bacteria is an example of
[A]
adaptive radiation
[B]
transduction
[C]
pre-existing variation in the population
[D]
divergent evolution.
Answer: pre-existing variation in the population
91
The bones of forelimbs of whale, bat, cheetah and man are similar in structure, because [NCERT Exemplar]
[A]
one organism has given rise to another
[B]
they share a common ancestor
[C]
they perform the same function
[D]
they have biochemical similarities.
Answer: they share a common ancestor
92
Analogous organs arise due to
[A]
convergent evolution
[B]
genetic drift
[C]
divergent evolution
[D]
artificial selection
Answer: convergent evolution
93
Which type of selection is industrial melanism observed in moth, Biston bitularia
[A]
Directional
[B]
Artificial
[C]
Stabilising
[D]
Disruptive
94
Select the correct statement from the following options.
[A]
Fitness is the end result of the ability to adapt and get selected by nature.
[B]
Darwinian variations are small and direction less.
[C]
Mutations are random and directional.
[D]
All mammals have evolved vivipary as an adaptation.
Answer: Fitness is the end result of the ability to adapt and get selected by nature.
95
Change of frequency of alleles in a population results in evolution. This statement is proposed in
[A]
Hardy-Weinberg principle
[B]
de Vries theory.
[C]
Darwin’s theory
[D]
Lamarck’s theory
Answer: Hardy-Weinberg principle
96
Darwin judged the fitness of individuals by
[A]
dominance over other individuals.
[B]
number of offspring produced.
[C]
ability to defend itself.
[D]
strategy to obtain food.
Answer: number of offspring produced.
97
Homologous organs indicate
[A]
divergent evolution.
[B]
adaptive radiation.
[C]
convergent evolution.
[D]
natural selection.
Answer: divergent evolution.
98
Evolutionary convergence is characterised by
[A]
development of characteristics by random mutations.
[B]
development of similar characteristics in different groups of organisms of different ancestry.
[C]
development of dissimilar characteristics in closely related groups of organisms.
[D]
development of similar characteristics in related groups of organisms.
Answer: development of similar characteristics in different groups of organisms of different ancestry.
99
Intensely lactating mothers do not generally conceive due to the [NCERT Exemplar]
[A]
suppression of gonadotropins.
[B]
hyper secretion of gonadotropins.
[C]
suppression of gametic transport.
[D]
suppression of fertilisation.
Answer: suppression of gonadotropins.
100
The oral contraceptive pills mainly contain the hormones
[A]
estrogen and luteinising hormone.
[B]
progesterone and estrogen.
[C]
estrogens and follicle-stimulating hormone.
[D]
progesterone and follicle-stimulating hormone.
Answer: progesterone and estrogen.
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