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. Acylglycerols
- B. Waxes
- C. Phospholipids
- D. Terpenoids
Explanation: Option B is correct. Cuticle is an example of waxes.The cuticle is an example of a protective layer.
Correct answer: Waxes- A. Long-chain alkanes
- B. Alcohols
- C. Aldehydes
- D. Esters of long-chain fatty acids and long-chain alcohols
Explanation: Option D is correct. Yes, esters of long-chain fatty acids and long-chain alcohols are the constituents of waxes.
Correct answer: Esters of long-chain fatty acids and long-chain alcohols- A. Energy currency of cell
- B. Contains ribose sugar
- C. Contains three high energy bonds
- D. Contains three phosphate groups
Explanation: Option C is correct. No, ATP does not contain three high-energy bonds. It actually contains two high-energy bonds.
Correct answer: Contains three high energy bonds- A. Monoterpene
- B. Diterpene
- C. Triterpene
- D. Polyterpene
Explanation: Diterpenes (C20H32) include physiologically active groups such as vitamin A and plant growth hormones that regulate germination…
Correct answer: Diterpene- A. mRNA
- B. tRNA
- C. rRNA
- D. Ribozyme
Explanation: The diagram shows tRNAThe following image shows another tRNA molecule.
Correct answer: tRNA- A. Maltose
- B. Lactose
- C. Raffinose
- D. Sucrose
Explanation: Sucrose, commonly known as table sugar, is a disaccharide sugar composed of two simple sugar molecules or monosaccharides: glucose and…
Correct answer: Sucrose- A. Carbohydrates
- B. Nucleic acids
- C. Proteins
- D. Lipids
Explanation: Wood, cotton and paper are made up of a polysaccharide called cellulose.
Correct answer: Carbohydrates- A. Carbohydrates
- B. Proteins
- C. Lipids
- D. Nucleic acids
Explanation: Cellulose, hemicellulose and pectins are the main components of the cell wall of plants and algae, whereas chitin is the main component of…
Correct answer: Carbohydrates- A. Lipids
- B. Proteins
- C. Water
- D. Nucleic acids
Explanation: By simple carbohydrates we mean monosaccharides with general formula of Cn(H2O)n.
Correct answer: Water- A. From three to many thousands
- B. From three to seven thousands
- C. From three to three thousands
- D. From seven to many thousands
Explanation: The smallest carbohydrate is a triose (monosaccharide) whereas the complex carbohydrates (Polysaccharides) may consist of hundreds or…
Correct answer: From three to many thousands- A. Carbohydrates
- B. Lipids
- C. Proteins
- D. Nucleic acids
Explanation: Chemically carbohydrates are either polyhydroxy aldehydes or polyhydroxy ketones or their condensation products.
Correct answer: Carbohydrates- A. Monosaccharides and oligosaccharides
- B. Glucose and fructose
- C. Monosaccharides and polysaccharides
- D. Oligosaccharides and polysaccharides
Explanation: Because these are condensationproducts of polyhydroxyaldehydes or polyhydroxy ketone units, thus they yield same upon their hydrolysis.
Correct answer: Oligosaccharides and polysaccharides- A. Lipids, Proteins
- B. Carbohydrates, Proteins
- C. Carbohydrates, Lipids
- D. Proteins, Lipids
Explanation: When carbohydrates are conjugated with proteins they yield glycoproteins and when conjugated with lipids they yield glycolipids.
Correct answer: Proteins, Lipids- A. Plant cell walls
- B. Algal cell walls
- C. Fungal cell wall
- D. Biological membrane
Explanation: Basic framework of cellular membranes is provided by proteins and lipids, however carbohydrates are conjugated with them to synthesize…
Correct answer: Biological membrane- A. Carbohydrates
- B. Monosaccharides
- C. Oligosaccharides
- D. Polysaccharides
Explanation: Monosaccharides such as glucose and fructose are crystalline solids at room temperature, but they are quite soluble in eater, each…
Correct answer: Monosaccharides- A. Except one
- B. Except two
- C. Without exception
- D. Except last
Explanation: That is why they are called polyhydroxy aldehydes or polyhydroxy ketones.
Correct answer: Except one- A. Number of carbon atoms
- B. Position of carbon atoms
- C. Position of hydrogen atoms
- D. Position of hydrogen and oxygen atoms
Explanation: If two hydrogen atoms from carbon number two of aldotriose are shifted to carbon number one it becomes Keto triose and vice versa.
Correct answer: Position of hydrogen atoms- A. DAP
- B. RuBP
- C. G.6.P
- D. G.3.P
Explanation: Dihydroxyacetone phosphate is a ketotriose.
Correct answer: DAP539. Pick up the triose:
- A. Glyceraldehyde
- B. Ribose
- C. Fructose
- D. Glucose
Explanation: It is an aldotriose i.e. a monosaccharide of three carbon atoms.
Correct answer: Glyceraldehyde- A. Trioses, tetroses
- B. Tetroses, pentoses
- C. Pentoses, hexoses
- D. Hexoses, heptoses
Explanation: Pentoses being part of nucleic acids and hexoses (glucose) being substrate for aerobic respiration are most common carbohydrates of nature.
Correct answer: Pentoses, hexoses