All Free Biology MCQs with Answers

4441. As the name indicates, it takes the genetic message from the nucleus to the ribosomes, in the cytoplasm to form the particular proteins:

• A. Ribosomal RNA
• B. Messenger RNA
• C. Transfer RNA
• D. DNA

Explanation: It takes the message encoded on genes to the ribosomes in cytoplasm where it is translated into proteins.

4442. It transfers amino acid molecules to the site where peptide chains are being sythesized:

• A. tRNA
• B. mRNA
• C. rRNA
• D. ScRNA

Explanation: It transfers appropriate amino acids to growing polypeptide chain.

4443. It may be upto 80% of the total RNA:

• A. tRNA
• B. mRNA
• C. rRNA
• D. SnRNA

Explanation: Quantitatively rRNA is the major form of RNA in cell.

4444. It acts as a machinery for synthesis of proteins:

• A. Golgi Apparatus
• B. Ribosomal RNA
• C. Mitochondria
• D. DNA of a gene

Explanation: It is used to make peptide bonds between amino acids and as a result polypeptide chain is synthesized.

4445. Nucleic acids were first isolated from:

• A. Human pus cells
• B. Fish sperm cells
• C. Human pus cells and fish sperm cells
• D. Human sperm cells and fish pus cells

Explanation: Frederick Miesher isolated a whitish substance from the nuclei of human pus cells and fish sperm cells and called it nuclien.

4446. How many possible double bonds may be present in fatty acids:

• A. Two
• B. Three
• C. Four
• D. Six

Explanation: Unsaturated fatty acids have double bonds.

4447. Specific gravity of fats and oils is:

• A. 0.8
• B. 1.8
• C. 0.6
• D. 0.08

Explanation: Specific gravity of fats and oils is 0.8.

4448. All are biological importance of water, EXCEPT:

• A. Polar molecule
• B. Universal solvent
• C. High specific heat and high heat of vaporization
• D. Water expands at high temperature

Explanation: Water has a unique property, as it expands when temperature falls below 4°C (39°F). Water is most heavy at 4°C ,therefore ice (solid water) is less dense than liquid water and this is the reason that ice floats in liquid water. Water body freezes on the surface at low temperature. Water has a high surface tension. In living cells this feature of surface tension allows a thin film of water to cover membranes and to keep them moist.

4449. The heat required to convert one gram of liquid water into vapors at its boiling point is called:

• A. Heat of condensation
• B. Heat of neutralization
• C. Specific heat
• D. Heat of vaporization

Explanation: The heat required to convert one gram of liquid water into vapors at its boiling point is called heat of vapourization.The heat of vaporization, also known as the enthalpy of vaporization, is the amount of heat energy required to convert a given quantity of a substance from its liquid phase to its gaseous phase at a constant temperature and pressure. In the case of water, it refers to the amount of heat energy needed to convert one gram of liquid water into vapor at its boiling point. This process requires the absorption of a significant amount of heat energy without a change in temperature.

4450. Which one of the following is not correct about water?

• A. Water has high specific heat
• B. Water has high heat of vaporization
• C. Water is not universal solvent
• D. Water exhibits strong cohesion tension

Explanation: Therefore, the option that is not correct about water is C ,water is not a universal solvent Water is actually a universal solvent because it can dissolve all polar and ionic substances.