Free Biological Molecules MCQs with Answers
1,790 Biological Molecules MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
The chapter covers water's polarity and biological roles, carbohydrates, lipids, proteins and nucleic acids, including their monomers, bonds, structures and functions. It also distinguishes RNA from DNA and explains conjugated molecules such as glycoproteins, glycolipids and nucleoproteins, which combine organic molecules with a non-protein component.
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- A. Double helical structure
- B. Ribose sugar
- C. Thymine
- D. Sugar - phosphate backbone
Explanation: As we can see that the double-helical structure and the nitrogenous base Thymine are exclusive to DNA, while RNA solely posses the Ribose…
Correct answer: Sugar - phosphate backbone- A. C5H10O5
- B. C5H8O4
- C. C5H10O4
- D. C5H8O3
- E. C5H10O3
Explanation: Explanation for this question will be added soon.
Correct answer: C5H10O4- A. 0
- B. 1
- C. 2
- D. 3
Explanation: Option A: This option suggests that there are no hydrogen bonds in a Cytosine-Guanine pair.
Correct answer: 3- A. Nerve cells.
- B. Brain cells.
- C. Bone cells.
- D. None of these.
Explanation: b) Brain cells: Brain cells, which include various types of neurons and glial cells, also contain a significant amount of water due to…
Correct answer: Brain cells.- A. 20
- B. 40
- C. 85
- D. 90
Explanation: Bone is a complex and rigid connective tissue that contains various components, including cells, fibres, and minerals.
Correct answer: 20- A. Water
- B. Protein
- C. Carbohydrates
- D. Lipids
Explanation: Water (Option A) forms almost three-fourths of the body by weight. The human body is composed of a significant amount of water, which…
Correct answer: Water- A. Hydrophilic exclusion
- B. Hydrophobic
- C. Specific heat capacity exclusion
- D. Heat of vaporization
Explanation: Biologically, the hydrophobic interactions (Option B) play key roles in maintaining the integrity of lipid bilayer membranes.
Correct answer: Hydrophobic- A. Reduction
- B. Oxidation
- C. Redox
- D. None of above
Explanation: The specific heat of vaporization of water plays an important role in the regulation of heat produced by OxidationSpecific heat of…
Correct answer: Oxidation- A. Nonpolar covalent bonds
- B. Polar covalent bonds
- C. Hydrogen bonds
- D. Covalent bonds
Explanation: For water to vaporize (turn from a liquid into a gas), the type of bond that must be broken is Hydrogen bondsWater molecules are held…
Correct answer: Hydrogen bonds- A. Glycosidic Bond
- B. Hydrogen Bond
- C. Peptide Bond
- D. Disulphide
Explanation: A glycosidic bond or glycosidic linkage is a type of covalent bond that joins a carbohydrate (sugar) molecule to another group.
Correct answer: Glycosidic Bond- A. Carboan, water and oxygen
- B. Carbon, Sulphur and hydrogen
- C. Carbon, calcium and hydrogen
- D. Carbon, ahydrogen and oxygen
Explanation: Carbohydrates are organic molecules, which are built out of carbon, hydrogen and oxygen molecules
Correct answer: Carbon, ahydrogen and oxygen1672. Starch is a polymer of:
- A. β-D-glucose
- B. α--glucose
- C. γ-D-glucose
- D. α-L-glucose
Explanation: Starch is a polysaccharide composed of repeating units of alpha-glucose molecules joined together through glycosidic bonds.
Correct answer: α--glucose- A. Waxes
- B. Glycerol
- C. Starch
- D. Cellulose
Explanation: Cellulose is the most abundant carbohydrate in nature due to its role as a structural component in the cell walls of plants.
Correct answer: Cellulose- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: This structure shows a six-membered ring (pyranose form) with the OH group on the anomeric carbon (carbon-1) pointing down relative to the…
Correct answer: Option A- A. Glycosidic Bond
- B. Keto group
- C. Maltose
- D. Fructose
Explanation: Monosaccharides are polyhydroxy aldehydes or polyhydroxy ketones. This implies that monosaccharides contain either an aldehyde group or a…
Correct answer: Keto group- A. Glucose
- B. Maltose
- C. Sucrose
- D. Mannose
Explanation: When starch is ultimately broken down into glucose molecules, this occurs after further hydrolysis of maltose or other intermediates.
Correct answer: Maltose- A. They are both polymers of glucose
- B. They are geometric isomers of each other
- C. They can both be digested by humans
- D. They are both used for energy storage in plants
Explanation: The statement that is true regarding both starch and cellulose is that they are both polymers of glucose.Both starch and cellulose are…
Correct answer: They are both polymers of glucose- A. Glucopyranose
- B. Ribofuranose
- C. Glyceraldehyde
- D. Acetaldehyde
Explanation: When most monosaccharides are in a solution, they tend to form ring structures.
Correct answer: Ribofuranose- A. Hydrolysis
- B. Oxidation
- C. Condensation
- D. Glycolysis
Explanation: Condensation is a chemical reaction in which two molecules combine to form a larger molecule, releasing a small molecule, often water, as…
Correct answer: Condensation- A. Fructose
- B. Glucose
- C. Ribose
- D. Deoxyribose
Explanation: Typically, glucose forms a six-membered ring called a pyranose. This ring consists of five carbon atoms and one oxygen atom.
Correct answer: Glucose