Life Sciences Multiple Choice Questions & Answers focuses on “Eukaryotic Chromatin and Chromosomes”.
1. Structure of DNA and protein found in the nucleus of eukaryotic cells___________
A. Nucleic acid
B. Nucleosome
C. Chromatin
D. Tetraplex
Answer: C
Clarification: Chromatin consists of single dsDNA in a coiled and condensed form which is an organized structure of DNA and proteins.
2. Centromere is located exactly at the center of the chromosomes.
A. True
B. False
Answer: B
Clarification: Centromere is the region in the eukaryotic chromosome where kinetochore is assembled and sister chromatids are held together. In some cases, centromere can also be located at the end of the chromosomes.
3. Which of the following is less condensed, less stained portion of chromatin?
A. Metaphase
B. Interphase
C. Heterochromatin
D. Euchromatin
Answer: D
Clarification: Less stained and less condensed portion of chromatin is euchromatin while a darkly stained and highly condensed region of chromatin is heterochromatin.
4. Name the part of a chromosome where t-loop is found.
A. Telomere
B. Centromere
C. Acromere
D. Tetraplex
Answer: A
Clarification: T-loop is found at the end of the chromosome or at the telomere region. It is responsible for the stability of the chromosomal ends.
5. Name the unit of replication?
A. DNA
B. Gene
C. Replicon
D. Chromosome
Answer: C
Clarification: Replicon is the unit of replication, which consists of its own origin of replication. Single chromatin has more than one replicon.
6. Which of the following phase is involved in the conversion of chromatin to chromosome?
A. S- phase
B. M- phase
C. G2- phase
D. G1- phase
Answer: B
Clarification: In G0 phase of non-dividing cells DNA exists as chromatin while in M-phase chromatin is converted to chromosome which is more condensed.
7. Name the basic structural unit of chromatin, which is described by R.Kornberg?
A. Scaffold protein
B. Solenoid
C. 30nm fiber
D. Nucleosome
Answer: D
Clarification: Nucleosome is the first level of DNA packing structure which is composed of beads-on-a-string structure. R.Kornberg in 1974 described the basic structure of chromatin.
8. What are protamines?
A. Large size DNA
B. Sequences that are unique
C. Histone like protein found in fish sperm
D. Highly repetitive DNA
Answer: C
Clarification: Protamine is a polypeptide basically composed of arginine and is present instead of histones in the sperm of fish and some other organisms.
9. Name the protein, which maintained the condensed structure of chromosomes.
A. HSP
B. SMC
C. Collagen
D. Elastin
Answer: B
Clarification: SMC stands for structural maintenance of chromosome protein, which maintained condensed structure of chromosomes.
10. Mark the process which does not involve in histone modification?
A. Acetylation
B. Methylation
C. Phosphorylation
D. Dehydration
Answer: D
Clarification: There are some chemical modification and structural changes take place in histones during replication and transcription called histone modification.
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