NEET UG Molecular Basis of Inheritance — practice questions
91 free MCQs with worked solutions. Tap any question for the answer + explanation, or practice them all in the app.
Practice NEET UG Molecular Basis of Inheritance in the app →DNA was first identified as an acidic substance in the nucleus by:In the Watson-Crick double helix, adenine pairs with thymine via how many hydrogen bonds?In a DNA molecule with 20% cytosine, what is the percentage of adenine?In the Watson-Crick model, the two polynucleotide strands of DNA are:The pitch of the DNA double helix is approximately:Two adjacent nucleotides in a polynucleotide chain are joined by:The chemical difference between DNA and RNA includes:In eukaryotes, the histone octamer around which DNA is wrapped to form a nucleosome consists of:Histones are positively charged because they are rich in:A typical nucleosome contains approximately how many base pairs of DNA?Heterochromatin (densely packed, dark-staining chromatin) is:In Griffith's experiment (1928) on Streptococcus pneumoniae, which combination killed the mice?
In the Hershey-Chase expWatson and Crick proposed which mode of DNA replication?In E. coli (~4.6 × 10⁶ bp), DNA replication is completed in approximately 18 minutes, giving an average rate oThe enzyme that joins the discontinuous Okazaki fragments on the lagging strand is:Replication does not initiate randomly along a DNA molecule; it starts at:The central dogma of molecular biology (Francis Crick) states:A transcription unit in DNA has three parts:In bacteria (e.g., E. coli), how many types of DNA-dependent RNA polymerases catalyse all RNA synthesis?In eukaryotes, RNA polymerase II transcribes:Of the 64 possible codons in the genetic code:The genetic code is described as 'degenerate' because:The genetic code was deciphered largely through the work of:tRNA is also called the 'adapter molecule' because it:The site of protein synthesis (translation) is the:The bond formed between two amino acids during translation is a:During translation, the activation of an amino acid and its linkage to its cognate tRNA is called:The lac operon (Jacob & Monod) consists of which structural genes?The lac operon is regulated by the lac repressor binding to the:In the absence of lactose, the lac operon is:According to HGP findings, what percentage of the human genome codes for proteins?Which of the following is NOT a step in classical DNA fingerprinting?Which of the following best supports the 'RNA world' hypothesis?In eukaryotes, exons are:Approximately how many genes does the human genome contain (per HGP)?In a DNA double helix, adenine pairs with thymine throughThe two strands of a DNA double helix areA nucleosome consists ofThe Hershey-Chase experiment used radioactive isotopes to labelThe Meselson-Stahl experiment proved that DNA replication isDNA polymerase synthesises a new DNA strand in which direction?In Griffith's experiment, mice injected with live R strain plus heat-killed S strain bacteriaThe central dogma of molecular biology states the flow of information asDuring transcription, the strand of DNA actually read by RNA polymerase isIntrons are best described asWhich eukaryotic RNA polymerase synthesises the mRNA precursor (hnRNA)?The total number of possible codons in the genetic code isWhich of the following is the universal start codon?In the lac operon, transcription of the lac genes is induced byApproximately how much of the human genome codes for proteins?Who proposed the double-helix model of DNA in 1953 using X-ray diffraction data from Wilkins and Franklin?In a DNA double helix, adenine pairs with thymine through how many hydrogen bonds?Which scientist first identified DNA in 1869 and named the acidic nuclear substance 'Nuclein'?The Human Genome Project was completed in which year?In the lac operon, the i gene codes for which protein?Which of the following is a stop codon?In the Hershey-Chase experiment, radioactive sulfur (35S) was used to specifically label which component of thIn the Meselson-Stahl experiment, DNA extracted one generation after the shift from 15N to 14N medium showed wA nucleosome in eukaryotic chromatin contains how many base pairs of DNA wrapped around the histone octamer?Which enzyme joins the discontinuously synthesised Okazaki fragments on the lagging strand?In eukaryotes, the primary transcript hnRNA is converted to mature mRNA by capping, tailing and splicing. WhatIn eukaryotes, which RNA polymerase transcribes the precursor of mRNA (hnRNA)?Which feature of the genetic code allows the same amino acid to be specified by more than one codon?In bacterial ribosomes, peptide bond formation is catalysed by which molecule?In Griffith's transformation experiment with Streptococcus pneumoniae, mice died when injected with which combIf the haploid human DNA is 3.3 x 10^9 bp and the distance between consecutive base pairs is 0.34 nm, the apprIf the pitch of the DNA helix is 3.4 nm and there are 10 base pairs per turn, the rise per base pair is:E. coli completes replication of its 4.6 x 10^6 bp genome in 18 minutes. The average polymerisation rate is clIn a transcription unit, the strand that has the polarity 3' to 5' and is used by RNA polymerase to direct RNAA double-stranded DNA contains 20% cytosine. What percentage of adenine is present?If the coding strand of a transcription unit reads 5'-ATGCATGCATGC-3', the mRNA transcribed will be:The true intracellular inducer of the lac operon is:Insertion of two extra bases in the middle of a structural gene most likely produces:Which RNA polymerase in eukaryotes transcribes 5S rRNA, tRNA and snRNAs?Which chromosome carries the largest number of genes and which carries the fewest, according to HGP?Sickle-cell anemia is caused by a point mutation in the beta-globin gene that substitutes:DNA fingerprinting developed by Alec Jeffreys originally used which type of repetitive sequence as a probe?Which step is NOT part of the classical DNA-fingerprinting workflow as described in NCERT?In bacterial transcription the sigma factor associates with RNA polymerase to:In a polynucleotide chain, two nucleotides are joined by which linkage, and at which carbon atoms of the sugarIn DNA, Adenine (A) pairs with Thymine (T) via:The Hershey-Chase experiment (1952) proved that:The Central Dogma of molecular biology states that genetic information flows:DNA replication is described as SEMI-CONSERVATIVE because:Okazaki fragments are produced during DNA replication on which strand?The START codon in eukaryotic mRNA translation is:Translation of mRNA into protein occurs on which cellular structure?The Lac Operon in E. coli is INDUCED (turned ON) by the presence of:The Human Genome Project (HGP) ran from 1990 to:During transcription, the enzyme that synthesises mRNA from DNA is: