🧬 Biochemistry Solved MCQs with Answers

Practice 1490 approved 🧬 Biochemistry questions with verified answers from the 🧬 Medical Science subject for Pakistan exams.

1490 solved MCQs

In some organelles in eukaryotes, the genetic code for some codonsAnswer: Differs from that used in prokaryotes The codons which do not specify an amino acid are calledAnswer: Termination code The genetic code is degenerated. Which of the following codons represents the principle of degeneracy?Answer: CAU and CAC The sequence of one strand of DNA is: 5' ATTGCCA 3', what is the sequence of the other strand?Answer: 5' TGGCAAT 3' In prokaryotes, AUG encodesAnswer: N-formyl methionine How many amino acids will be encoded by 5' GAU GGU UGA UGU 3' sequence?Answer: Two In protein synthesis in prokaryotesAnswer: The initiating amino acid is N- formyl methionine AUG codes for methionine act as aAnswer: Initiation code Translation beginsAnswer: At the start codon The accepted hypothesis for DNA replication isAnswer: Semi-conservative theory When DNA polymerase is in contact with guanine in the parental strand, what does it add to the growing daughter strand?Answer: Cytosine Telomeres are usually rich in which nucleotide?Answer: Guanine Which is the largest among the followings?Answer: Nucleotide The chromosomal DNA complexes withAnswer: Five types of histone as H1, H2A, H2B, H3 and H4 Taylor, Woods and Hughes labeled Vicia DNA by allowing new DNA synthesis in the presence of radioactive thymine. After DNA replication (S phase of the cell cycle), it was observed thatAnswer: Both chromatids of a chromosome were labeled In DNA double helix, the two DNA chains are held together byAnswer: Hydrogen bonds between the pair of bases The 5' and 3' numbers are related to theAnswer: Carbon number in sugar Messelsen and Stahl model of replication was calledAnswer: Semi-conservative replication The most common liquid volumes in molecular biology are measured inAnswer: μl DNA replication takes place in which direction?Answer: 5 'to 3' DNA gyrase in E. coliAnswer: Can be inhibited with antibiotics In DNA, there areAnswer: Four bases known as adenine, guanine, thymine and cytosine In DNA, guanine pairs withAnswer: Cytosine Which of the following is incorrect?Answer: None of these What is the only common methylation in the DNA of eukaryotes?Answer: Cytosine in CpG dinucleotides DNAs when charged, migrate in a gel towards theAnswer: Positive pole What is the approximate size (in kb) of the E. coli genome?Answer: 4500 kilobase In the study of one experiment it was found that the value of Tm for DNA is = 40° C. If the cell has 20% GC at the above Tm, then what will be value of 'Tm' if the GC% increases to 60%?Answer: Increases What is the range of melting point temperatures (Tm) for most DNA molecules?Answer: 80 to l00°C The overall conclusion of the Hershey-Chase experiment was thatAnswer: DNA was responsible for heredity