MCQ Bank

Friedrich Wöhler synthesized urea from inorganic starting materials in 1828. This experiment was an important milestone in disproving the idea that organic compounds could only be produced by living organisms.

MB502T Mid Term Verified

Q70

The linkage between two amino acids removes a __ molecule__

A) H2O
B)
C)
D)

AI Explanation

Two amino acids form a peptide bond through a condensation reaction. A molecule of water (H2O) is removed when the amino group of one amino acid reacts with the carboxyl group of another.

MB502T Mid Term Verified

Q71

Amino acid attach to__ end of tRNA.___

A) 3’
B)
C)
D)

AI Explanation

Amino acids are attached to the 3′ end of tRNA, specifically to the terminal adenosine of the CCA sequence. The attachment forms a high-energy ester bond catalyzed by an aminoacyl-tRNA synthetase.

MB502T Mid Term Verified

Q72

The junction between the newly separated template strands and the ___ dsDNA is known as _____

A) unreplicated , replication fork
B)
C)
D)

AI Explanation

The replication fork is the junction where newly separated template DNA strands meet the still-unreplicated double-stranded DNA. It is the site where DNA unwinding and synthesis occur.

MB502T Mid Term Verified

Q73

DNA bound histone in the eukaryotes is___

A) chromatin
B)
C)
D)

AI Explanation

In eukaryotes, DNA is associated with histone proteins to form chromatin. Histones help package and organize the long DNA molecule within the nucleus.

MB502T Mid Term Verified

Q74

During DNA replication each strand serve as___

A) Template
B)
C)
D)

AI Explanation

During DNA replication, each parental DNA strand serves as a template for synthesis of a complementary new strand. This complementary copying is the basis of semiconservative replication.

MB502T Mid Term Verified

Q75

Mutation is necessary evil as __

A) not all mutations give advantage to organism
B)
C)
D)

AI Explanation

Mutations are a source of genetic variation and are important for evolution, but they are not necessarily beneficial. Many mutations are neutral or harmful, so their effects can vary among organisms.

MB502T Mid Term Verified

Q76

Replication machine achieves remarkably high degree of accuracy ___

A) proofreading mechanism
B)
C)
D)

AI Explanation

The replication machinery achieves high accuracy through proofreading mechanisms associated with DNA polymerases. Incorrectly incorporated nucleotides are detected and removed before DNA synthesis continues.

MB502T Mid Term Verified

Q77

The RNA AU/GC ratio was roughly ___ to the DNA AT/GC ratio___

A) similar
B)
C)
D)

AI Explanation

The AU/GC ratio of RNA was found to be roughly similar to the AT/GC ratio of DNA. This observation helped establish relationships between RNA composition and its DNA template.

MB502T Mid Term Verified

Q78

Strands of DNA are separated at the replication fork___

A) dsDNA
B)
C)
D)

AI Explanation

At the replication fork, the double-stranded DNA (dsDNA) is unwound and its two strands are separated. Each separated strand then acts as a template for synthesis of a new complementary strand.

MB502T Mid Term Verified

Q79

PAH stands for___

A) Polycyclic Aromatic Hydrocarbons
B)
C)
D)

AI Explanation

PAH is the abbreviation for polycyclic aromatic hydrocarbons. These compounds consist of multiple fused aromatic rings and can arise from incomplete combustion of organic materials.

MB502T Mid Term Verified

Q80

Nucleic acids are ___

A) polymeric compounds
B)
C)
D)

AI Explanation

Nucleic acids are polymers made up of repeating nucleotide units. DNA and RNA are the two major types of nucleic acids.

MB502T Mid Term Verified

Q81

RNA contain how many ribonucleotides___

A) 5
B)
C)
D)

AI Explanation

The question's provided answer indicates five ribonucleotides. RNA commonly contains the four standard ribonucleotides—adenine, guanine, cytosine, and uracil—along with modified ribonucleotides in some biological contexts.

MB502T Mid Term Verified

Q82

____ are exceptionally simple and extremely small microorganisms.____

A) viruses
B)
C)
D)

AI Explanation

Viruses are exceptionally simple and extremely small infectious agents. They consist primarily of nucleic acid surrounded by a protein coat and depend on host cells for replication.

MB502T Mid Term Verified

Q83

Simplest amino acid residues ____

A) glycine
B)
C)
D)

AI Explanation

Glycine is the simplest amino acid because its side chain is only a hydrogen atom. Its small size also gives proteins considerable conformational flexibility at glycine residues.

MB502T Mid Term Verified

Q84

First discovered enzyme___

A) Diastase
B)
C)
D)

AI Explanation

Diastase is recognized as the first enzyme to be discovered. It was identified by Anselme Payen and Jean-François Persoz in 1833 while studying starch degradation.

MB502T Mid Term Verified

Q85

Transition mutation example____

A) Alkylation Damage to DNA
B)
C)
D)

AI Explanation

Alkylation damage can alter bases and cause mispairing during DNA replication, producing transition mutations. A transition is a substitution in which a purine replaces another purine or a pyrimidine replaces another pyrimidine.

MB502T Mid Term Verified

Q86

Rosalind Franklin & Maurice wilkins discovered DNA by _____

A) X-ray diffraction
B)
C)
D)

AI Explanation

Rosalind Franklin and Maurice Wilkins used X-ray diffraction techniques to study the structure of DNA. Their diffraction images provided crucial evidence for DNA's helical structure.

MB502T Mid Term Verified

Q87

Types of nucleotides___

A) 5
B)
C)
D)

AI Explanation

There are five major types of nucleotides when considering the standard nitrogenous bases found in nucleic acids: adenine, guanine, cytosine, thymine, and uracil. DNA uses four of these, while RNA uses uracil instead of thymine.

MB502T Mid Term Verified

Q88

How many types of ribonucleic acids are present in body___

A) three
B)
C)
D)

AI Explanation

The three major types of RNA found in cells are messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). Each has a distinct role in gene expression and protein synthesis.