Free Chromosomes MCQs with Answers
633 Chromosomes MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Chromosomes are DNA-protein structures that carry genes and become visible during cell division. Coverage includes chromatin, centromeres, sister chromatids, homologous chromosomes, chromosome number, and the distinction between diploid and haploid cells, with links to DNA replication, mitosis and meiosis.
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633 questions · page 11 of 32
- A. Sigma factor
- B. GC + AT base pairs
- C. U ribonucleotide
- D. Core enzyme
Explanation: It is a protein in prokaryotic organisms (such as bacteria) that assists RNA polymerase in recognizing the promoter region of a gene…
Correct answer: Sigma factor202. Stop signal:
- A. GC + AT base pairs
- B. 3' end
- C. U ribonucleotide
- D. Core enzyme
Explanation: Uridine (U) ribonucleotide, when found in messenger RNA (mRNA), can be related to a stop signal through the presence of a specific…
Correct answer: U ribonucleotide203. Poly A tail:
- A. Core enzyme
- B. U ribonucleotide
- C. 3' end
- D. Sigma factor
Explanation: The poly-A tail is a stretch of adenine nucleotides added to the 3' end of pre-messenger RNA (pre-mRNA) during mRNA processing.
Correct answer: 3' end- A. U ribonucleotide
- B. Core enzyme
- C. Sigma factor
- D. GC + AT base pairs
Explanation: The transcription bubble forms during transcription, where the DNA double helix temporarily unwinds, creating a single-stranded template…
Correct answer: GC + AT base pairs205. Phenylketonuria:
- A. ACC
- B. Peptidyl site
- C. Phenylalanine
- D. Chromosomal aberration
Explanation: PKU is a genetic disorder that causes an inability to metabolize phenylalanine, an amino acid found in protein-containing foods.
Correct answer: Phenylalanine206. Inversion:
- A. Chromosomal aberration
- B. 1000 nucleotides/sec
- C. Phenylalanine
- D. Peptidyl site
Explanation: Chromosomal aberrations are abnormalities in the structure or number of chromosomes in a cell.
Correct answer: Chromosomal aberration207. Polymerase III:
- A. Peptidyl site
- B. Phenylalanine
- C. 1000 nucleotides/sec
- D. ACC
Explanation: DNA polymerase III is an enzyme involved in DNA replication in prokaryotes, such as bacteria.
Correct answer: 1000 nucleotides/sec208. Phenylketonuria is
- A. Sex linked dominant trait
- B. Sex linked recessive trait
- C. Autosomal dominant trait
- D. Autosomal recessive trait
Explanation: Phenylketonuria (PKU) is a rare inherited disorder that causes an amino acid called phenylalanine to build up in the body.
Correct answer: Autosomal recessive trait- A. DNA is broken up at specific sites
- B. DNA fragments are joined together
- C. DNA replication occurs
- D. DNA transcription occurs
Explanation: DNA ligases play an essential role in maintaining genomic integrity by joining breaks in the phosphodiester backbone of DNA that occur…
Correct answer: DNA fragments are joined together- A. mRNA
- B. rRNA
- C. tRNA
- D. Polysome
- E. Genes
Explanation: Option A is messenger RNA, the transcript of a segment of DNA that serves as the code which is then translated by the ribosomes.
Correct answer: rRNA- A. Trait
- B. Centromere
- C. Genotype
- D. Locus
Explanation: A locus is a specific, fixed position on a chromosome where a particular gene or genetic marker is located.
Correct answer: Locus- A. Deoxyribose sugar
- B. Ribose sugar
- C. Phosphate group
- D. Sequence of nitrogenous bases
- E. Sequence of phosphate group
Explanation: The genetic information of DNA is encoded as the sequence of nitrogenous bases.
Correct answer: Sequence of nitrogenous bases- A. Position
- B. Frequency
- C. Copy
- D. Inversion
Explanation: Factual recall; The locus describes the position of the gene on a chromosome, so option A is correct.Option B, frequency, is generally…
Correct answer: Position- A. Kinetochore
- B. Locus
- C. Allele
- D. Gene
Explanation: The gene is the basic physical and functional unit of heredity. It consists of a specific sequence of nucleotides at a given position on a…
Correct answer: Gene- A. TACGGATCCTG
- B. UAGCGAUCCUG
- C. AUGCCUAGGAC
- D. UACCGAUCCUG
- E. GCAUUCGAAGU
Explanation: DNA strand serves as the template for RNA synthesis. The RNA nucleotide sequence is complementary to that of DNA template strand except…
Correct answer: UACCGAUCCUG- A. Transcriptase
- B. Polymerase
- C. Reverse transcriptase
- D. Synthetase
Explanation: Option A, transcriptase, is an RNA dependent RNA polymerase, which forms RNA strands by using RNA strands as a template.
Correct answer: Reverse transcriptase- A. Peptide bond
- B. Phosphodiester bond
- C. Glycosidic bond
- D. Ester bond
Explanation: When nucleotides are incorporated into DNA, adjacent nucleotides are linked by a phosphodiester bond: a covalent bond is formed between…
Correct answer: Phosphodiester bond- A. DNA polymerase
- B. Ligase
- C. Primase
- D. Endonuclease
Explanation: DNA polymerase adds nucleotides to the three prime (3')-end of a DNA strand, one nucleotide at a time. So option A is incorrect.
Correct answer: Ligase- A. DNA
- B. Protein
- C. RNA
- D. A and C
Explanation: Mutation can occur in DNA and RNA i.e alteration in bases of DNA and RNA. Mutations can not occur in proteins.
Correct answer: A and C- A. 6th
- B. 5th
- C. 4th
- D. 3rd
- E. 1st
Explanation: The nitrogenous bases are purines or pyrimidines. The nitrogen base is attached to the C-1 of the pentose sugar.
Correct answer: 1st