laboursonline – MCQs, Mock Tests | Biology Biology MCQ Question

Receptors for hearing come under heading of

1. Chemical
2. Mechanical
3. Photo
4. Nociceptors

✅ Correct Answer: 2

Which of the following feature is not related to neuron

1. Conduction
2. Regeneration
3. Reflex
4. Movement

✅ Correct Answer: 2

Value of resting membrane potential is

1. 0.03 V
2. 0.05 V
3. 0.07 V
4. 0.09V

✅ Correct Answer: 3

Number of pairs of cranial nerves is

1. 10
2. 11
3. 12
4. 13

✅ Correct Answer: 3

Insufficient secretion of iodothyroxine in adults causes

1. Myxedema
2. Cretinism
3. Goiter
4. Exopthalmic goiter

✅ Correct Answer: 1

Insulin and glucagons are ________ in nature.

1. Protein
2. Amino acid derivative
3. Polypeptide
4. Steroid

✅ Correct Answer: 1

Acromegaly is caused due to oversecretion of

1. STH
2. TSH
3. ACTH
4. Thyroxin

✅ Correct Answer: 4

MSH is produced from

1. Anterior pituitary
2. Median pituitary
3. Posterior pituitary
4. None of these

✅ Correct Answer: 2

Secretin is a hormone produced by

1. Stomach
2. Liver
3. Pancreas
4. Duodenum

✅ Correct Answer: 4

All of the following are similarities between nervous and endocrine system except

1. Produce chemical messengers
2. Release chemical messengers in extracellular space
3. Homestatic in function
4. Having slow but prolonged effects

✅ Correct Answer: 4

Types of behaviour enabling pillbugs to reach moist area is

1. Kinesis
2. Taxes
3. Instinct
4. Learning

✅ Correct Answer: 1

_________ was first to propose an objective definition of instinct.

1. Thorpe
2. Darwin
3. Pavlov
4. Kohler

✅ Correct Answer: 2

_______ is simplest form of learning.

1. Imprinting
2. Habituation
3. Insight learning
4. Latent learning

✅ Correct Answer: 2

Which is incorrect?

1. Chromosomes 1st observed by walther Fleming
2. Chromosomal theory of inheritance 1st formulated by Walter Sutton
3. 1st evidence of hereditary nature of DNA provided by Friedrich Meischer
4. Sex chromosomes discovered by Thomas Hunt Morgan

✅ Correct Answer: 2

Chromosome is made of

1. 2 chromatids +1 centromere +secondary constriction
2. 1 chromated + 1 centromere + primary constriction
3. 2 chromatids + 1 centromere + primary constriction
4. 2 chromatids + 2 centromere + secondary constriction

✅ Correct Answer: 1

Chromosomes are composed of

1. 40% protein and 60% DNA
2. 50% protein and 50% DNA
3. 70% protein and 30% DNA
4. 60% protein and 40% DNA

✅ Correct Answer: 4

A typical human chromosome contains _________ nucleotides in its DNA

1. 240 million
2. 140 million
3. 150 million
4. 160 million

✅ Correct Answer: 2

Histones have abundance of amino acids

1. Valine and lysine
2. Arginine and lysine
3. Valine and arginine
4. Histidione and threonine

✅ Correct Answer: 2

A tortion of chromatin that is condensed only during cell division is

1. Euchromatin
2. Heterochromatin
3. Biochromatin
4. Nucleochromatin

✅ Correct Answer: 1

Transfer of genetic material from one cell to another that can alter the genetic makeup of recipient cell is called

1. Mutation
2. Transuction
3. Replication
4. Variation

✅ Correct Answer: 2

Who discovered DNA?

1. P.A.Levene
2. Frederick Griffith
3. Friedrich Miescher
4. Rosalind Franklin

✅ Correct Answer: 3

DNA contains

1. Purines (A and G) pyrimidines (U and (c)
2. Purines (T and (c) pyrimidines (A and G)
3. Purines (A and (c) pyrimidines (U and G)
4. Purines (A and G) pyrimidines (T and (c)

✅ Correct Answer: 4

In DNA

1. A forms two bonds with T
2. G forms three bonds with C
3. A forms three bonds with T
4. Both a and b

✅ Correct Answer: 4

DNA has a helical shape with the diameter of

1. 3 nm
2. 4 nm
3. 2 nm
4. 5 nm

✅ Correct Answer: 3

In semi-conservative replication

1. Sequence of original duplex is conserved after one round of replication
2. Gererate DNA copies of entirely new molecules
3. Parental DNA become completely dispersed
4. Each strand of daughter molecules will be a mixture of old and new

✅ Correct Answer: 1

The true E.Coli replicating enzyme is

1. DNA polymerase I
2. DNA polymerase II
3. DNA polymerase III
4. All of these

✅ Correct Answer: 3

Rate of DNA replication by DNA polymerase is

1. 2000 nucleotides / sec
2. 1000 nucleotides / sec
3. 150 nucleotides / sec
4. 1050 nucleotides / sec

✅ Correct Answer: 2

Which statement is correct?

1. Leading strand elongates away from the replication fork
2. Lagging strand elongates towards the replication fork
3. Lagging strand is constructed discontinuously.
4. Both a and b

✅ Correct Answer: 3

The length of okazaki fragments in eukayotes is

1. 150--250 nucleotides long
2. 200-300 nucleotides
3. 1000-2000 nucleotdes
4. 100-200 nucleotides

✅ Correct Answer: 4

The sequence of nucleotides that determines the amino acid sequence of a protein is

1. Chromosome
2. DNA
3. RNA
4. Gene

✅ Correct Answer: 4

Central dogma is

1. Transfer of information from DNA to mRNA
2. Basic mechanism of reading and expressing genes
3. Transfer of information from RNA to proteins
4. Synthesis of all three types of RNA

✅ Correct Answer: 2

In prokaryotes there are

1. Three types of DNA polymerases
2. One type of RNA polymerase
3. Three types of RNA polymerase
4. Both a and b

✅ Correct Answer: 4

Human cell contains ______ different kinds of tRNA molecules

1. 25
2. 35
3. 45
4. 15

✅ Correct Answer: 3

In eukaryotes newly synthesized mRNA

1. Travels a large distance from nucleus to cytoplasm
2. Is directly released into the cytoplasm
3. Contains a cap and tail
4. Both a and c

✅ Correct Answer: 4

Which 3 codons are nonsense codons?

1. UAA,UAU,UUA
2. UGA,UAG,UAA
3. UGG,UGA,UAU
4. UGG,UAA,UAG

✅ Correct Answer: 2

Methionine is specified by

1. Stop codon
2. AUG
3. Start codon
4. Both b and c

✅ Correct Answer: 4

In mitochondria UGA is/specifies as

1. Stop codon
2. Tryptophan
3. Initiation codon
4. Methionine

✅ Correct Answer: 2

Three nucleotide sequence on tRNA that specifies an amino acis is

1. Codon
2. Anticodon
3. Nonsense codon
4. Genetic code

✅ Correct Answer: 2

Initiation complex in translation is composed of

1. Ribosome and aminoacyl-tRNA
2. Ribosome and tRNA
3. tRNA and aminoacyl-tRNA
4. None of these

✅ Correct Answer: 1

Point mutations are represented as

1. Presence of an extra chromosome
2. Loss of chromosome
3. Alteration in sequence of DNA nucleotide
4. Insertions and inversion of genes

✅ Correct Answer: 3

Strand of DNA which is not transcribed is called

1. Antisense
2. Template
3. Coding
4. None of these

✅ Correct Answer: 3

Phenylketonuria is due to deficiency of

1. Phenylalnine
2. Phenylalanine hydroxylase
3. Phenylene
4. All of these

✅ Correct Answer: 2

Molecular basis of sickle cell anaemia was found by

1. F. Sanger
2. Beadle and Tatum
3. Vernone Ingram
4. Mendal

✅ Correct Answer: 3

Which is incorrect about nucleosome

1. 2 turns of DNA coiled round histones
2. 8 histones as acidic proteins
3. 200 nucleotides in one nucleosome
4. None of these

✅ Correct Answer: 2

Sex chromosomes were 1" discovered in

1. Man
2. Pea plant
3. Fruitfly
4. None of these

✅ Correct Answer: 3

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Biology MCQ Question - Chromosome and DNA