Cell Biology MCQs | BIO201 MCQs | Set 2
Cell Biology MCQs | BIO201 MCQs | Set 2
MCQs (Multiple Choice Questions)
1) If one gene prevent the expression of other gene
a) Pleiotropy
b) Epistasis
c) Synapse
d) Tetrad
Correct Answer:
The correct answer is 'b'.
Explanation:
The term "epistasis" refers to a genetic interaction where one gene (called the "epistatic" gene) can prevent the expression of another gene (called the "hypostatic" gene). In other words, the epistatic gene masks or modifies the effects of the hypostatic gene. This is a form of genetic interaction that can affect the expression of one gene by the presence or activity of another gene.
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2) Phenylalanine hydroxylase metabolizes
a) Phenylalanine to Lysine
b) Phenylalanine to Tyrosine
c) Tyrosine to Phenylalanine
d) Lysine to Phenylalanine
Correct Answer:
The correct answer is 'b'.
Explanation:
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3) Restriction enzymes inhibit the growth of
b) Bacteria
d) None
Correct Answer:
The correct answer is 'a'.
Explanation:
Restriction enzymes are a part of the bacterial defense system against bacteriophages, which are viruses that infect and replicate within bacteria. These enzymes are used by bacteria to cut the DNA of invading bacteriophages at specific recognition sequences, preventing the phages from replicating within the bacterial host. So, restriction enzymes inhibit the growth of bacteriophages, not bacteria themselves. This is a crucial mechanism of bacterial immunity against viral infection.
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4) Missing of enzyme homogentisic acid oxidase caused
a) Phenylketonuria
b) Parkinson disease
c) Alkaptonuria
d) Cystic fibrosis
Correct Answer:
The correct answer is 'c'.
Explanation:
The missing enzyme in the disorder Alkaptonuria is homogentisic acid oxidase. This enzyme is responsible for the metabolism of homogentisic acid, and its deficiency results in the accumulation of homogentisic acid in the body. This accumulation leads to the characteristic darkening of the urine and other symptoms associated with Alkaptonuria. Therefore, the missing enzyme in Alkaptonuria is homogentisic acid oxidase, not homogentisic acid itself.
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5) Microtubules are originated from
a) Cytoskeletal
b) Nucleus
c) Proteins
d) Centrosomes
Correct Answer:
The correct answer is 'd'.
Explanation:
Microtubules are a part of the cytoskeleton, and they are organized and nucleated from a cellular structure called the centrosome. The centrosome is often referred to as the microtubule-organizing center (MTOC) of the cell. It is responsible for nucleating and organizing microtubules, which play a crucial role in various cellular processes such as cell division, intracellular transport, and maintaining cell shape. So, the centrosome is the site from which microtubules originate in the cell.
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6) The disintegration and condensation of nuclear material takes place in
a) prophase II
b) anaphase II
c) metaphase II
d) telophase II
Correct Answer:
The correct answer is 'd'.
Explanation:
The disintegration and condensation of nuclear material occur during telophase II of meiosis. In meiosis, telophase II is the stage when the separated chromatids (resulting from the anaphase II stage) reach the opposite poles of the cell. During telophase II, the nuclear envelope reforms around the separated chromatids, leading to the formation of two distinct nuclei in each of the four daughter cells. This process involves the disintegration of the nuclear envelope from the previous stage and the condensation of the chromatids into distinct, organized chromosomes within the newly formed nuclei.
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7) RNAs in large subunit of Eukaryotic ribosome
a) 1
b) 2
c) 3
d) 4
Correct Answer:
The correct answer is 'c'.
Explanation:
The large subunit of the eukaryotic ribosome contains three RNAs: 5S rRNA, 5.8S rRNA, and 28S rRNA.
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8) Centromeres separate during whose anaphase:
a) Mitosis
b) meiosis I
c) meiosis II
d) None
Correct Answer:
The correct answer is 'c'.
Explanation:
Meiosis is a type of cell division that produces gametes (sex cells). It involves two rounds of cell division, meiosis I and meiosis II. During meiosis I, homologous chromosomes pair up and exchange genetic material in a process called crossing over. The homologous chromosomes then separate during anaphase I, resulting in two haploid daughter cells.
During meiosis II, the sister chromatids of each chromosome separate, resulting in four haploid daughter cells. The centromeres of the sister chromatids separate during anaphase II.
In mitosis, the centromeres of the sister chromatids separate during anaphase. Mitosis is a type of cell division that produces two identical daughter cells.
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9) Enormous genetic information is present in
a) RNA
b) DNA
c) Nucleolus
d) Nucleoplasm
Correct Answer:
The correct answer is 'b'.
Explanation:
DNA (deoxyribonucleic acid) is a molecule that encodes the genetic instructions used in the development and functioning of all known living organisms and many viruses. The main role of DNA is the long-term storage of information for building proteins, which are the fundamental units of life.
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10) Okazaki fragments are joined by:
a) Ligase
b) Gyrase
c) Helicase
d) Primase
Correct Answer:
The correct answer is 'a'.
Explanation:
DNA ligase is an enzyme that catalyzes the formation of a phosphodiester bond between two DNA strands. During DNA replication, the lagging strand is synthesized discontinuously in short fragments called Okazaki fragments. Okazaki fragments are joined together by DNA ligase to form a continuous strand of DNA.
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