Bihar Board 12th Biology Objective Important Questions Part 2
Question 1.
A group of genes are getting deleted and undergoing some change it is due to:
(a) Gene mutation
(b) Aneuploidy
(c) Chromosomal mutation
(d) Gene modification
Answer:
(c) Chromosomal mutation
Question 2.
Which one is a disease in which one extra X-chromosome present?
(a) Down’s syndrome
(b) Turner’s syndrome
(c) Klinefelter’s syndrome
(d) Bleeder’s syndrome
Answer:
(c) Klinefelter’s syndrome
Question 3.
In which type of mutation minute changes occur?
(a) Point mutation
(b) Frame shift mutation
(c) Backward mutation
(d) Forward mutation
Answer:
(a) Point mutation
Question 4.
In diploid organism crossing over takes place that is responsible for:
(a) Linkage between genes
(b) Segregation of alleles
(c) Dominance of genes
(d) Recombination of linked genes
Answer:
(d) Recombination of linked genes
Question 5.
An individual with genotype Aa Bb the gametes will form:
(a) Aa, Bb
(b) AB, ab
(c) AB, ab, aB
(d) AB, ab, aB, Ab
Answer:
(d) AB, ab, aB, Ab
Question 6.
The law of purity of gametes is given by Mendel on the basis of:
(a) Monohybrid cross
(b) Dihybrid cross
(c) Test cross
(d) Back cross
Answer:
(a) Monohybrid cross
Question 7.
Smallest segment of genetic material affected by mutation is:
(a) Recen
(b) Cistron
(c) Muton
(d) Exon
Answer:
(c) Muton
Question 8.
The allele which is unable to express its effect in the presence of another is called:
(a) Codominant
(b) Supplementary
(c) Complementary
(d) Recessive
Answer:
(d) Recessive
Question 9.
A homozygous plant having red flowers is crossed with a homozygous plant bearing white flowers. The offsprings are:
(a) All with white flowers
(b) All with red flowers
(c) Half with white flowers
(d) Half with red flowers
Answer:
(b) All with red flowers
Question 10.
Lack of independent assortment of two genes A & B in fruit fly, Drosophila is due to:
(a) Recombination
(b) Linkage
(c) Crossing over
(d) Repulsion
Answer:
(b) Linkage
Question 11.
Crossing over occurs between two homologous chromosomes in:
(a) Leptotene
(b) Zygotene
(c) Pachytene
(d) Diplotene
Answer:
(c) Pachytene
Question 12.
In turner syndrome the chromosomes are:
(a) 44A + XO
(b) 44A + XXY
(c) 44A + XXX
(d) 44A + XYY
Answer:
(a) 44A + XO
Question 13.
Mother is homozygous B, and father is A. What will be the blood group in their progeny?
(a) AB & A
(b) AB & B
(c) A & B
(d) AB
Answer:
(b) AB & B
Question 14.
Down’s syndrome is due to:
(a) Linkage
(b) Sex-linked inheritance
(c) crossing over
(d) Non-disjunction of chromosome
Answer:
(d) Non-disjunction of chromosome
Question 15.
Test Cross is a cross between:
(a) Hybrid (F1) dominant parent
(b) Hybrid (F1) × recessive parent
(c) Hybrid (F1) × Hybrid (F1)
(d) Two distantly related species
Answer:
(b) Hybrid (F1) × recessive parent
Question 16.
The inheritance of which of the following is controlled by multiple alleles?
(a) Clour blindness
(b) Sickle cell anaemia
(c) Phenylketonuria
(d) Blood group
Answer:
(d) Blood group
Question 17.
In chromosomal mutation if genes ABCDEFGH is changed as ADCBEFGH. This change in genes position represents:
(a) Deletion
(b) Duplication
(c) Inversion
(d) Translocation
Answer:
(c) Inversion
Question 18.
Father is colour blind and mother is normal, the children will be:
(a) Daughters will be carrier
(b) Sons will be normal
(c) Sons will be colour blind
(d) None of the above
Answer:
(a) Daughters will be carrier
Question 19.
The nearest relatives of man are:
(a) Old world monkeys
(b) New world monkeys
(c) Apes
(d) Lemurs
Answer:
(c) Apes
Question 20.
The fossil man found from the Shivalik hills of India is:
(a) Australopithecus
(b) Ramapithecus
(c) Homo sapiens
(d) Cro-magnon man
Answer:
(b) Ramapithecus
Question 21.
Human evolution occurred in:
(a) Africa & America
(b) Africa & Asia
(c) Asia & Australia
(d) America & Australia
Answer:
(b) Africa & Asia
Question 22.
Which one is connecting link between animals & plants is:
(a) Virus
(b) Bacteria
(c) Euglena
(d) Amoeba
Answer:
(c) Euglena
Question 23.
Wings of birds & butterflies are:
(a) Homologous organs
(b) Analogous organs
(c) Vestigial organs
(d) Atavistic organs
Answer:
(b) Analogous organs
Question 24.
The theory of use and disuse of organs was given by:
(a) Weismann
(b) Lamarck
(c) Darwin
(d) Huxley
Answer:
(b) Lamarck
Question 25.
The book “Philosophic Zoologique” was written by:
(a) Hugo de vries
(b) Mendel
(c) Haeckel
(d) Lamarck
Answer:
(d) Lamarck
Question 26.
The most harmful struggle is between:
(a) Inter specific
(b) Intra specific
(c) Extra specific
(d) All of these
Answer:
(b) Intra specific
Question 27.
‘Ontogeny recapitulates phytogeny’ is a theory in favour of evidences of evolution is given by:
(a) Darwin
(b) Herbert spencer
(c) Hackel
(d) Morgan
Answer:
(c) Hackel
Question 28.
The organs those are similar in structure and origin but different in functions are known as:
(a) Homologous
(b) Analogous
(c) Vestigial
(d) both (a) & (b)
Answer:
(a) Homologous
Question 29.
Who proposed the “Theory of origin of species” by Natural selection?
(a) Hugo devries
(b) Charles Darwin
(c) Weismann
(d) Charles Darwin & Alfred Wallace
Answer:
(d) Charles Darwin & Alfred Wallace
Question 30.
Which one show convergent evolution?
(a) Rat & Dog
(b) Dog fish & Whale
(c) Starfish & Cuttle fish
(d) Bacterium & Protozoan
Answer:
(b) Dogfish & Whale
Question 31.
Darwin made a sea voyage for:
(a) 2 yrs
(b) 4 yrs
(c) 3 yrs
(d) 5 yrs
Answer:
(d) 5 yrs
Question 32.
Theory of Pangenesis was given by:
(a) Weismann
(b) Darwin
(c) Lamarck
(d) Hugo devries
Answer:
(b) Darwin
Question 33.
Mesozoic era is the age of:
(a) Fishes
(b) Reptiles
(c) Birds
(d) Mammals
Answer:
(b) Reptiles
Question 34.
Synthesis of DNA is called:
(a) Transcription
(b) Translation
(c) Replication
(d) Amination
Answer:
(c) Replication
Question 35.
Hydrogen bonds between cytosine & guanine are:
(a) 1
(b) 2
(c) 3
(d) 4
Answer:
(c) 3
Question 36.
Which one is not involved in protein synthesis:
(a) Transcription
(b) Initiation
(c) Termination
(d) Elongation
Answer:
(a) Transcription
Question 37.
RNA contains:
(a) Hexose
(b) Ribose
(c) Fructose
(d) Glucose
Answer:
(b) Ribose
Question 38.
Who proved that DNA is the basic genetic material?
(a) Griffith
(b) Sutton & Boveri
(c) Hershey & Chase
(d) Watson
Answer:
(c) Hershey & Chase
Question 39.
A gene of operon which synthesizes a repressor protein is:
(a) Regulator gene
(b) Promoter gene
(c) Operator gene
(d) Structural gene
Answer:
(a) Regulator gene
Question 40.
‘One gene-one enzyme’ hypothesis states that:
(a) one gene codes for one enzyme
(b) one gene codes for one polypeptide
(c) one gene codes for many enzymes
(d) one gene regulates all enzymes
Answer:
(b) one gene codes for one polypeptide
Question 41.
Out of the total 64 codons, 61 codons code for 20 amino acids, this suggests that:
(a) Degeneracy of codons
(b) overlapping of codons
(c) Ambiguous nature of codons
(d) Redundacy of codons
Answer:
(a) Degeneracy of codons
Question 42.
Temin & Baltimore are associated with the discovery of:
(a) Transcription
(b) RNA synthesis
(c) Reverse transcription
(d) Transposons
Answer:
(c) Reverse transcription
Question 43.
DNA replication is semiconservative was practically proved by:
(a) Hargovind Khorana
(b) Watson & Crick
(c) Meselson & Stahl
(d) Tayler
Answer:
(c) Meselson & Stahl
Question 44.
The synthesis of DNA as lagging strand takes place in segments, these segments are called:
(a) Double helix segments
(b) Satellite segment
(c) Komberg segment
(d) Okazaki segment
Answer:
(d) Okazaki segment
Question 45.
The term genome denotes:
(a) Haploid set of chromosomes
(b) Bivalent
(c) Monovalent
(d) Diploid set of chromosomes
Answer:
(a) Haploid set of chromosomes
Question 46.
DNA sequences that code for protein are known as:
(a) Intron
(b) Exons
(c) Control region
(d) Intervening sequences
Answer:
(b) Exons
Question 47.
In human chromosomes with the highest and least number of genes are present respectively in:
(a) Chromosomes 1 & x
(b) Chromosome 1 & y
(c) Chromosome 22 & x
(d) chromosome x & y
Answer:
(b) Chromosome 1 & y
Question 48.
Which of the following are the functions of RNA?
(a) It carries the genetic information from DNA to ribosomes synthesising polypeptides
(b) It carries amino acids to ribosomes
(c) It is a constituent component of ribosomes
(d) All of the above
Answer:
(d) All of the above
Question 49.
Instrons are:
(a) Coding part of m-RNA
(b) Gene present of DNA
(c) Non-coding part of m-RNA
(d) Sequence of essential amino acids
Answer:
(c) Non-coding part of m-RNA
Question 50.
The most stable RNA is:
(a) m-RNA
(b) t-RNA
(c) r-RNA
(d) s-RNA
Answer:
(c) r-RNA