All Free Biology MCQs with Answers

• A. Gene of interest
• B. Molecular scissors
• C. Molecular glue and expression system
• D. All of the above

Explanation: Recombinant DNA technology makes use of all the molecular components mentioned above, as the main purpose of this technology, in simple words, is to cut a piece of DNA (gene of interest) from a DNA segment, using molecular scissors. This is proceeded by inserting the isolated gene into the DNA of the host organism and by using the molecular glue, it is ensured that the foreign gene segment is permanently placed into the host's DNA.

• A. Employed by forensic scientists to assist in the identification of individuals by their respective type of DNA
• B. Collect all the genes found in one complete set of chromosome
• C. Is a technique to separate different-sized fragments of charge-bearing polymers (proteins, RNA or DNA)
• D. Grows a single cell or a group of cells in glassware on an artificial medium under aseptic conditions

Explanation: Gel electrophoresis is a laboratory method used to separate mixtures of DNA, RNA, or proteins according to molecular size. In gel electrophoresis, the molecules to be separated are pushed by an electrical field through a gel that contains small pores.

• A. Have a foreign gene inserted into them
• B. Have an important role in the large scale production of medicinal products
• C. Are considered beneficial to humans
• D. All of the above

Explanation: Transgenic organisms have all three characteristics mentioned in options A-C. They have a foreign gene inserted in them, they play an important role in the large-scale profusion of different types of products like insulin, which is a medicinal commodity. These transgenic organisms are thus considered beneficial to human beings due to the above-stated qualities.

• A. dATP
• B. Primers
• C. DNA fragments
• D. Ribonucleotides

Explanation: DNA primer is not required for a PCR reaction. The reason for RNA primers to be used in PCR is the non availability of DNA primers. The RNA primers complimentary to the cellular DNA are easily synthesized by the DNA Primase enzyme which is nothing but RNA polymerase just like mRNA.

• A. Na+ ions
• B. K+ ions
• C. CI- ions
• D. Ca2+ ions
• E. Mg2+ ions

Explanation: Cystic fibrosis is due to the lack of Cl- protein channels which leads to decreased movement of chloride ions outside the cell, and thus water, leading to thickened mucus. All other options are wrong as Na+, K+, Ca+2 ,Mg+2 are not involved in Cystic fibrosis.

• A. Bacterial diseases only
• B. Viral diseases only
• C. Both Viral and Bacterial
• D. All type of disease-causing organisms

Explanation: Live, attenuated vaccines fight viruses and bacteria.Currently, there are no immunotherapeutics or vaccines approved for the treatment or prevention of fungal infections.

• A. Chemically synthesized
• B. Synthesized from mRNA
• C. Synthesized by using terminating nucleotides
• D. Chemically cut into pieces

Explanation: This method is based on nucleobase-specific partial chemical modification of DNA and subsequent cleavage of the DNA backbone at sites adjacent to the modified nucleotides.

• A. Sexual reproduction
• B. Asexual reproduction
• C. Both sexual and asexual
• D. None of the given options

Explanation: Cloning is an asexual method of reproduction, where fertilization or inter-gamete contact does not take place.

• A. Agar gel
• B. Agarose gel
• C. Dextran
• D. Toluene gel

Explanation: Agarose gel is used during gel electrophoresis. The restriction fragments can be separated according to their length (molecular weight or size) when it is run on the agarose gel.

• A. It can be isolated from chromosome
• B. It can be synthesized chemically
• C. It can be made from protein
• D. It can be made from mRNA

Explanation: Recombinant DNA (rDNA) technology has made the transfer of genes from one organism to another possible