OJEE Molecular Basis of Inheritance — practice questions
64 free MCQs with worked solutions. Tap any question for the answer + explanation, or practice them all in the app.
Practice OJEE Molecular Basis of Inheritance in the app →DNA was first isolated and named **nuclein** by:Griffith's 1928 transformation experiments used the bacterium:The **Hershey-Chase** experiment (1952) used:DNA replication is best described as:The semiconservative nature of DNA replication was experimentally proved by:A **nucleosome** consists of:**Central dogma** of molecular biology (Crick, 1958) states the flow of information as:The genetic code is a:The **initiation codon** for translation is:Which of the following is **not** a stop codon?In Griffith's transformation experiment, the 'transforming principle' was later identified by Avery, MacLeod aThe **histones** that wrap DNA into nucleosomes are positively charged because they are rich in which amino acDuring DNA replication, the **lagging strand** is synthesised:**Okazaki fragments** on the lagging strand are joined together by the enzyme:**Reverse transcription** (RNA → DNA) is a hallmark of:During **transcription** in eukaryotes, m-RNA is transcribed by:In the structural gene of a transcription unit, the **template strand** has polarity:How many codons in the standard genetic code (a) total exist, (b) are stop codons, (c) code for amino acids?Wobble hypothesis explains:Translation occurs at the **ribosome**. The codon currently being read sits at the:**Introns** in eukaryotic primary transcripts are:In the Meselson-Stahl experiment, *E. coli* grown on ¹⁵N then switched to ¹⁴N gives, after **two** generationsDNA polymerase synthesises new DNA strand in the:Key features of the **genetic code** include all of the following EXCEPT:Cloverleaf t-RNA structure has, at the 3'-acceptor end, the universal sequence:If the anticodon of a tRNA is **3'-UAC-5'**, the corresponding mRNA codon is (read 5'→3'):An insertion or deletion of **one or two** bases in a coding sequence (not a multiple of three) causes:The **30-nm chromatin fibre** in eukaryotic chromosomes arises by: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)?