All Free Biology MCQs with Answers

• A. Bacteria
• B. Slicing of DNA
• C. Bacterial virus
• D. Attaches to the host

Explanation: Enterobacteria phage λ (lambda phage, coliphage λ, officially Escherichia virus Lambda) is a bacterial virus, or bacteriophage, that infects the bacterial species Escherichia coli (E. coli). It was discovered by Esther Lederberg in 1950.

• A. Replication
• B. Replacing
• C. To search the genetic library
• D. Slicing of DNA

Explanation: A genomic library is a collection of DNA segments (clones) from the species of interest, inserted in a microbial vector. This library can be screened with a labeled probe of known sequence to select clones containing the same or similar sequences.

• A. Replacing
• B. Slicing of DNA
• C. Replication
• D. To search the genetic library

Explanation: DNA polymerase is the enzyme responsible for replicating DNA - for using a template strand to construct a complimentary sequence of nucleotides, creating a double-stranded DNA molecule. DNA polymerase can also proofread the new strand as it is created and is involved in repairing DNA damage and mutations:

• A. Sanger's method
• B. To diagnose viral infection
• C. Maxam and Gilbert method
• D. RFLPs

Explanation: Restriction fragment length polymorphism (abbreviated RFLP) refers to differences (or variations) among people in their DNA sequences at sites recognized by restriction enzymes. Such variation results in different sized (or length) DNA fragments produced by digesting the DNA with a restriction enzyme ...

• A. As evidence for paternity
• B. RFLPs
• C. Maxam and Gilbert method
• D. To diagnose viral infection

Explanation: DNA finger prints shows comparison of child's inger print with that of his parents. The child has received DNA from both of his parents. Arrows indicate that some bands in him are like his father, some like his mother. Some bands are. however, unique to him, which do not match with any of the parents.

• A. RFLPs
• B. To diagnose viral infection
• C. Maxam - Gilbert method
• D. Sanger's method

Explanation: PCR-based strategies have propelled huge scientific endeavors such as the Human Genome Project. The technique is currently widely used by clinicians and researchers to diagnose diseases, clone and sequence genes, and carry out sophisticated quantitative and genomic studies in a rapid and very sensitive manner.

• A. Bacteria that reproduce in large vats
• B. Viruses
• C. Smallest chromosome
• D. A restriction enzyme cuts DNA

Explanation: When the DNA sequence of human chromosome no. 22, one of the smallest human chromosomes.

• A. Smallest chromosome
• B. Bacteria that reproduce in large vats
• C. A restriction enzyme cuts DNA
• D. Viruses

Explanation: A restriction enzyme is a protein isolated from bacteria that cleaves DNA sequences at sequence-specific sites, producing DNA fragments with a known sequence at each end. The use of restriction enzymes is critical to certain laboratory methods, including recombinant DNA technology and genetic engineering.persons with Huntington disease have a unique site where a restriction enzyme cuts DNA.

• A. Viruses
• B. Smallest chromosome
• C. A restriction enzyme cuts DNA
• D. Determines the order of base pairs

Explanation: DNA sequence is now completely automated, robotic devices mix the reagents and then load, run and read the order of the nucleotide bases from the gel.

• A. Promote health of plants
• B. Used to make holes in the plasma membrane
• C. An organic chemical used to make aspartame
• D. Used to stimulate the sperms to divide

Explanation: Transgenic bacteria have been produced to promote health of plants for example, bacteria that normally live on plants and encourage the formation of ice crystals have been changed from frost - plus to frost - minus bacteria