NCERT Class 12 Biology General Awareness Questions with Answers
NCERT Class 12 Biology
QUESTIONS
NCERT Class 12 Biology General Awareness Questions with Answers
61 In the immune system, interferons are a part of
A cytokine barriers.
B physical barriers
C physiological barriers
D cellular barriers
Answer: cytokine barriers.
62 ZIFT is transfer of
A zygote into fallopian tube.
B a mixture of sperms and ova into the fallopian tube.
C a mixture of sperms and ova into the uterus.
D embryo into the uterus.
Answer: zygote into fallopian tube.
63 Diaphragms are the contraceptive devices used by females. Choose the correct option about them.
A They are placed to cover the cervix.
B They block the entry of sperms.
C They are reusable.
D All of these.
64 The most accepted line of descent in human evolution is
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
65 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
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.
66 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
67 When ‘Aa’ is crossed with ‘aa’, (A is dominant over a)
A all the offspring will have dominant phenotype.
B all the offspring will have recessive phenotype.
C 50% of offspring will have dominant phenotype and 50% will have recessive phenotype.
D 75% of offspring will have dominant phenotype and 50% will have recessive phenotype.
Answer: 50% of offspring will have dominant phenotype and 50% will have recessive phenotype.
68 The possibility of all genotypes of offspring in a genetic cross is calculated by a graphical representation which was developed by
A Gregor Mendel
B Reginald Punnett
C Komberg
D T.H. Morgan
69 Study the pedigree chart given
Select the correct option about the conclusion.
A It is a sex-linked recessive trait.
B It is an autosomal recessive trait.
C It is an autosomal dominant trait.
D It is a sex-linked dominant trait.
Answer: It is an autosomal recessive trait.
70 Mother and father of a person with ‘O’ blood group have ‘A’ and ‘B’ blood group respectively. What would be the genotype of both mother and father?
A Mother is homozygous for ‘A’ blood group and father is heterozygous for ‘B’.
B Mother is heterozygous for ‘A’ blood group and father is homozygous for ‘B’.
C Both mother and father are heterozygous for ‘A’ and ‘B’ blood group, respectively.
D Both mother and father are homozygous for ‘A’ and ‘B’ blood group, respectively.
Answer: Both mother and father are heterozygous for ‘A’ and ‘B’ blood group, respectively.