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 12 of 32
- A. Euchromatin
- B. Heterochromatin
- C. Nucleosome
- D. Super coils
- E. None of these
Explanation: Highly condensed portions of chromatin are called heterochromatin. Euchromatin is the uncondensed portion of DNA.
Correct answer: Heterochromatin- A. 44 + XX
- B. 44 + XY
- C. 44 + XXY
- D. 44 + XO
- E. 44 + XXX
Explanation: The genotype of a normal male contains 44 autosomes and two sex chromosomes, which are XY.
Correct answer: 44 + XY- A. Only one daughter cell will have heavy DNA
- B. Two daughter cells have normal DNA and other two have heavy DNA
- C. All daughter cells have heavy DNA
- D. Half daughter cells have heavy DNA and other half have normal DNA
Explanation: After two divisions, four bacterial cells are formed in which two daughter bacterial cells have normal DNA and other two have both normal…
Correct answer: Two daughter cells have normal DNA and other two have heavy DNA- A. Down's Syndrome
- B. Turner's Syndrome
- C. Klinefelter's Syndrome
- D. Sickle cell anemia
- E. Color blindness
Explanation: Klinefelter syndrome is a genetic condition in which a boy is born with an extra X chromosome.
Correct answer: Klinefelter's Syndrome- A. 10
- B. 20
- C. 30
- D. 40
- E. 44
Explanation: Haploid cells are formed by reduction division, which has half the number of chromosomes than diploid cells.
Correct answer: 44- A. 2
- B. 3
- C. 4
- D. 6
- E. 9
Explanation: Zygote(3) formed by the fusion of sperm(1) and ovum(2) is the first cell to have a diploid number of chromosomes.
Correct answer: 3- A. 21 and 42
- B. 7 and 21
- C. 21 and 7
- D. 42 and 21
Explanation: Wheat, Triticum, has basic chromosome number, n = 7; thus the hexaploid species (Triticum aestivum) have 6n = 42.
Correct answer: 21 and 7- A. Complementary strand of DNA which codes for one amino acid
- B. Complementary strand of mRNA which codes for one amino acid
- C. tRNA molecule where the amino acid is attached
- D. tRNA molecule which recognizes the appropriate sequence of bases on the mRNA
- E. mRNA molecule which instructs the ribosomes to initiate
Explanation: Anticodons are present on the tRNA molecules which complement codons on the mRNA molecules, which is mentioned in statement D.
Correct answer: tRNA molecule which recognizes the appropriate sequence of bases on the mRNA- A. Nitrogenous bases
- B. Ribose Sugars
- C. Deoxyribose Sugars
- D. Phosphate groups
- E. Adenine
Explanation: Deoxyribose sugars are not part of RNA, rather ribose sugars are part of RNA. Deoxyribose sugars are found in DNA molecules.
Correct answer: Deoxyribose Sugars- A. Metacentric
- B. Submetacentric
- C. Acrocentric
- D. Telocentric
Explanation: Chromosomes with the centromere located near the middle and with two equal arms on either side are called metacentric chromosomes.
Correct answer: Metacentric- A. 12
- B. 24
- C. 46
- D. 48
Explanation: Mitosis is a process of cell duplication, in which one cell divides into two genetically identical daughter cells.
Correct answer: 24- A. GUG
- B. CAU
- C. UGC
- D. GAG
Explanation: The transfer RNA has complementary base pairs to mRNA. The unique amino acid in sickle cell is valine, the mRNA codons of valine are GUG…
Correct answer: CAU- A. They are formed during meiosis.
- B. They are held together by centromeres.
- C. They are chromatids of the same chromosome.
- D. They carry both morphologically similar members with same set of genes.
Explanation: The homologous chromosomes are made before meiosis, so option A is incorrect.
Correct answer: They carry both morphologically similar members with same set of genes.234. Phenotype is:
- A. The genetic component i.e. the genes in an individual for a particular trait
- B. Partner of gene pair
- C. The form of appearance of a trait
- D. The position of a gene on the chromosome
Explanation: A phenotype is an individual's observable traits, such as height, eye color, and blood type.
Correct answer: The form of appearance of a trait- A. DNA polymerase
- B. RNA polymerase
- C. DNA transcriptase
- D. RNA transcriptase
Explanation: RNA polymerase is the main transcription enzyme. RNA polymerase uses one of the DNA strands (the template strand) as a template to make a…
Correct answer: RNA polymerase- A. Genotype
- B. Phenotype
- C. Karyotype
- D. Allele
Explanation: A karyotype is an individual's collection of chromosomes. Presented below is a karyogram.
Correct answer: Karyotype- A. Option A
- B. Option B
- C. Option C
- D. Option D
- E. Option E
Explanation: The DNA sequence will bealanine - GCA = CGT arginine - CGA = GCTlysine - AAG = TTCphenylalanine - UUU = AAA
Correct answer: Option A- A. 16%
- B. 18%
- C. 32%
- D. 36%
Explanation: 32% of the nitrogenous bases are cytosine so 32% of the nitrogenous bases are guanine, according to Chargaff's rule.
Correct answer: 36%- A. 2
- B. 3
- C. 4
- D. 6
Explanation: The number of adenine base pairs on one strand is equal to thymine base pairs on the other strand and the cytosine base pairs are equal to…
Correct answer: 4- A. Mitosis
- B. Meiosis
- C. Geographic distribution
- D. Active transport
Explanation: Crossing over is the exchange of genetic material between non-sister chromatids of homologous chromosomes during meiosis, which results in…
Correct answer: Meiosis