Free Cell Structure and Function MCQs with Answers
2,478 Cell Structure and Function MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Animal, plant, prokaryotic and eukaryotic cells are compared through their membranes, cell walls, nuclei and cytoplasmic organelles. The work includes the structures and functions of mitochondria, chloroplasts, ribosomes, endoplasmic reticulum, Golgi apparatus and lysosomes, as well as chromosome organization and the distinction between chromatin and chromosomes.
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Read the Cell Structure and Function notesFree MDCAT chapter notes with key terms2,478 questions · page 100 of 124
- A. AAAT box
- B. TATA box
- C. GGTT box
- D. CAAT box
Explanation: The DNA sequence that holoenzyme RNA polymerase binds to during transcription, and the DNA assumes a saddle-like structure at that point…
Correct answer: TATA box- A. Protein structure
- B. DNA replication
- C. Protein synthesis pattern
- D. RNA transcription pattern
Explanation: After a mutation at a genetic locus, the character of an organism changes due to a change in protein structure.
Correct answer: Protein structure- A. rRNA
- B. hnRNA
- C. mRNA
- D. tRNA
Explanation: The form of RNA that has a structure resembling the cloverleaf is tRNA (transfer RNA).
Correct answer: tRNA- A. TATGC
- B. TCTGG
- C. UAUGC
- D. UATGC
Explanation: During transcription, the nucleotide sequence of the mRNA is complementary to the nucleotide sequence of the DNA template strand, with the…
Correct answer: UAUGC- A. Frame shift mutation
- B. Transcription
- C. Transition
- D. Transversion
Explanation: When adenine replaces guanine because of a mutation, it is called a transition.
Correct answer: Transition- A. A + G / C + T
- B. T + C / G + A
- C. G + C / A + T
- D. A + C / T + G
Explanation: According to Chargaff's rules:A = T and G = CThe GC content (G + C) and AT content (A + T) vary between species but are constant within a…
Correct answer: G + C / A + T- A. Lactose
- B. Lactase
- C. Lac insect
- D. The number 1,00,000
Explanation: In the lac operon, lac refers to lactose. The lac operator is a part of the structural genes (lac Z, lac Y, lac A, and lac I).
Correct answer: Lactose- A. UCG - start
- B. UUU - stop
- C. UGU - leucine
- D. UAC - tyrosine
Explanation: Codon UAC is correctly matched as it codes for the amino acid tyrosine.
Correct answer: UAC - tyrosine- A. Promoter
- B. Regulator
- C. Receptor
- D. Enhancer
Explanation: The DNA site at which RNA polymerase binds during transcription is called the promoter.
Correct answer: Promoter- A. First member of a codon
- B. Second member of codon
- C. Entire codon
- D. Third member of a codon
Explanation: Degeneration of a genetic code is attributed to the third codon member.
Correct answer: Third member of a codon- A. 20%
- B. 40%
- C. 30%
- D. 60%
Explanation: In a DNA, the percentage of guanine is equal to the percentage of cytosine, and the percentage of adenine is equal to the percentage of…
Correct answer: 30%- A. E.coli
- B. Diplococcus pneumoniae
- C. Salmonella
- D. Pasteurella pestis
Explanation: The transformation experiment was first conducted by Frederick Griffith in 1928 using the bacterium Streptococcus pneumoniae, also known…
Correct answer: Diplococcus pneumoniae- A. All prokaryotes
- B. All prokaryotes and some eukaryotes
- C. All prokaryotes and all eukaryotes
- D. All prokaryotes and some protozoans
Explanation: The operon model was given by Jacob and Monod (1961) for the regulation of protein synthesis in prokaryotes only.
Correct answer: All prokaryotes- A. Proteins
- B. Lipid
- C. Carbohydrates
- D. Phospholipids
Explanation: DNA transcribes to form mRNA. Its function is to carry coded information from DNA for the synthesis of proteins.
Correct answer: Proteins1995. In negative operon,
- A. Co-repressor binds with repressor
- B. Co-repressor does not bind with repressor
- C. Co-repressor binds with inducer
- D. cAMP have negative effect on lac operon
Explanation: The tryptophan operon (trp operon) in bacteria is repressible. Here, the repressor is inactive, and it becomes active as DNA DNA-binding…
Correct answer: Co-repressor binds with repressor- A. One cistron contains many genes
- B. One gene contains many cistrons
- C. One gene contains one cistron
- D. One gene contains no cistron
Explanation: A gene is a hereditary unit consisting of a sequence of DNA and occupying a specific position or locus within the genome.
Correct answer: One gene contains one cistron- A. 3.4 nm
- B. 0.34 nm
- C. 20 nm
- D. 10 nm
Explanation: B-DNA is an antiparallel double helix. The double-strand or duplex is coiled plectonemically in a right-handed fashion around a common…
Correct answer: 3.4 nm- A. Both are polymer of nucleotides
- B. Both have similar pyrimidine
- C. Both have similar sugar
- D. Both are genetic material
Explanation: Deoxyribonucleic acid and ribonucleic acid are made up of several nucleotide monomers.
Correct answer: Both are polymer of nucleotides- A. Bacteria do not reproduce sexually
- B. RNA sometime controls the production of DNA and proteins
- C. DNA is the genetic material
- D. Bacteria undergo binary fission
Explanation: Transformation was first discovered by Griffith (1928) in Pneumococcus (Streptococcus pneumoniae), which causes pneumonia.
Correct answer: DNA is the genetic material2000. DNA is mainly found in:
- A. Nucleolus
- B. Nucleus only
- C. Cytoplasm only
- D. None of these
Explanation: DNA is mainly found in the nucleus. It is associated with RNA and proteins to form compact chromosomes.
Correct answer: Nucleus only