All Free Biology MCQs with Answers

• A. Restriction endonucleases
• B. Reverse transcriptase
• C. Restriction nucleases
• D. Restriction exonucleases

Explanation: A restriction enzyme, restriction endonuclease, REase, ENase or restrictase is an enzyme that cleaves DNA into fragments at or near specific recognition sites within molecules known as restriction sites. Restriction enzymes are one class of the broader endonuclease group of enzymes.

• A. Replicator
• B. Thermocycler
• C. Chemocycler
• D. Cycler

Explanation: PCR-Machines are based on Polymerase Chain Reaction (PCR) and produce copies of genes exponentially. The PCR cycling reactions are carried out in an automated thermocycler, which is capable of heating and cooling the reaction tubes in a short span of time.

• A. Plasma
• B. Blood
• C. Serum
• D. All of these

Explanation: The biological material used to determine a DNA profile include blood, semen, saliva, urine, feces, hair, teeth, bone, tissue and cells.

• A. Precursor molecules
• B. Pollutants
• C. Totipotent
• D. Activators

Explanation: In chemistry, a precursor is a compound that participates in a chemical reaction that produces another compound. In biochemistry, the term "precursor" often refers more specifically to a chemical compound preceding another in a metabolic pathway, such as a protein precursor.

• A. Herbicide
• B. Gremicide
• C. Insecticide
• D. Fungicide

Explanation: Herbicide resistant plants are Wheat, rice, sugar beets, canola.

• A. Eggs
• B. Body cells
• C. Eggs and sperms
• D. Bacteria

Explanation: Bacterial cells take up recombinant plasmid, especially, if they are treated with calcium chloride to make them more permeable.

• A. Ecology
• B. Physiology
• C. Morphology
• D. Biotechnology

Explanation: Urine is a preferable vehicle for a biotechnology product than milk because all animals in a herd urinate - only females produce milk; animals start to urinate at birth - females don't produce milk until maturity; and its easier to extract proteins from urine than from milk.

• A. Episomes vehicles
• B. Liposomes vehicles
• C. Eposomes vehicles
• D. Disomic vehicles

Explanation: Cystic fibrosis patients lack a gene that codes for trans-membrane carrier of the chloride ion. Patients often die due to numerous infections of the respiratory tract. And in vivo method of treatment is being tried. Liposomes-microscopic vesicles that spontaneously form when lipoproteins are put into a solution, have been coated with the gene needed to cure cystic fibrosis. Then the solution is sprayed into patient's nostrils. Due to limited gene transfer, this methodology has not as yet been successful.

• A. Stomach
• B. Blood
• C. Brain
• D. Kidneys

Explanation: To cure Parkinson's disease, dopamine-producing cells could be grafted directly into the brain.

• A. Hybridization
• B. Mutations
• C. Variations
• D. Somaclonal variations

Explanation: Somaclonal variation is the variation seen in plants that have been produced by plant tissue culture. Chromosomal rearrangements are an important source of this variation.