Biology
Molecular Biology and Genetics
717 Questions
Molecular biology and genetics explore the structure and function of DNA, RNA, genetic mutations, and heredity. Understanding these building blocks of life is essential for most biology examinations. Review these practice questions to test your molecular genetics knowledge.
DNA structure and basesGenetic mutationsNucleic acids compositionDNA sequencing and replication
Molecular Biology and Genetics Questions
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all adenine
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all uridine
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pseudouridine
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pseudothymine
C
Correct answer
Explanation
TΨC arm is made up of pseudouridine and that is why, it is named TΨC arm. Ψ stands for pseudouridine.
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It is the “other strand” of a DNA.
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It does not need any template for its synthesis.
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It is the base sequence of the vector DNA.
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It is produced by reverse transcription.
D
Correct answer
Explanation
Complementary DNA (cDNA) is produced by reverse transcription.
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6-aminopurine
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2-oxy-4-amino-pyrimidine
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2, 4-dioxypyrimidine
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2, 4-dioxy-5-methylpyrimidine
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2-amino-6-oxypurine
C
Correct answer
Explanation
Uracil (2, 4-dioxypyrimidine) is not a part of DNA.
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6-aminopurine
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2-oxy-4-amino-pyrimidine
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2, 4-dioxypyrimidine
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2, 4-dioxy-5-methylpyrimidine
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2-amino-6-oxypurine
D
Correct answer
Explanation
Thymine (2, 4-dioxy-5-methylpyrimidine) is not a part of RNA.
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GGU,GGC,GGA,GGG
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CUU,CUC,CUA,CUG
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GCU,GCC,GCA,GCG
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GUU,GUC,GUA,GUG
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GCU,GCC,GCA,GGG
D
Correct answer
Explanation
GUU,GUC,GUA,GUG represents valine.
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hydrogen bonds
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peptide bonds
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disulphide bonds
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phosphate diester bonds
D
Correct answer
Explanation
In DNA, two nucleotides are linked by phosphate diester bonds.
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TTAGGC
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TTAGGU
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TTAGGG
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ATAGTG
C
Correct answer
Explanation
Human Telomeric sequence is: TTAGGG
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5' to 3' direction
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3' to 5' direction
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no specific direction
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5' to 5' direction
A
Correct answer
Explanation
DNA chain growth occurs in 5' to 3' direction.
C
Correct answer
Explanation
The AT base pairs have only two hydrogen bonds, which are easy to unzip. Therefore, AT-rich sequences act as origin of DNA replication.
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ds circular DNA
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SS circular DNA
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ds Linear DNA
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SS Linear DNA
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Formed of RNA
A
Correct answer
Explanation
A plasmid is a small, circular, double-stranded DNA molecule, which is distinct from chromosomal DNA.
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Copy DNA
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Complementary DNA
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Coupled DNA
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Compound DNA
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Complex DNA
B
Correct answer
Explanation
Complementary DNA (cDNA) is DNA synthesised from a messenger RNA (mRNA) template in a reaction catalysed by the enzymes reverse transcriptase.
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Non-overlapping
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AUG is a non sense codon.
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No punctuation
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Specificity
B
Correct answer
Explanation
Out of 64 codons, the two codons namely AUG and GUG are called the initiation codons as they begin the synthesis of polypeptide.
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nucleosome
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chromatin
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nuclein
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histones
C
Correct answer
Explanation
This option is correct, DNA was first identified by Friedrich Meischer in 1869. He named it nuclein.
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Nucleosome
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Chromatin
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Euchromatin
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Heterochromatin
A
Correct answer
Explanation
This option is correct, DNA is wrapped around the histone octamer to form a nucleosome. A typical nucleosome contains 200 bp of DNA helix.
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Cytosine
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Guanine
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Uracil
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Thymine
B
Correct answer
Explanation
This option is correct, guanine is a purine, not a pyrimidine.