All Free Biology MCQs with Answers

4451. Ice floats because:

• A. It is less dense than water
• B. It is more dense than water
• C. It occupies less space than water
• D. It occupies more space than water

Explanation: Therefore, the correct statement for why ice floats is A becuase water has a unique property, as it expands when temperature falls below 4°C. Water is most heavy at 4°C, therefore ice (solid water) is less dense then liquid water and this is that ice float is liquid water.

4452. After taking a shower, you notice that some water droplets are clinging to the shower curtain. This is an example of:

• A. Adhesion
• B. Cohesion
• C. Ionic bonding
• D. Surface tension

Explanation: Adhesion refers to the tendency of water molecules to be attracted, or "stick", to other substances. This is a result of the covalent bond between the two hydrogen atoms and the one oxygen atom in the water molecule. Just like a magnet, the poles of water molecule allow it to stick to other polar substances.Adhesion refers to the attractive force between the molecules of different substances. In the case of water droplets clinging to the shower curtain, it is an example of adhesion. The water molecules are attracted to the molecules of the shower curtain, causing them to stick or adhere to the surface. Adhesion occurs due to the intermolecular forces, such as hydrogen bonding, between water molecules and the molecules of the shower curtain. Therefore A is the correct option.

4453. The formation of a large molecule from two small molecules with the removal of water is called:

• A. Condensation
• B. Hydrolysis
• C. Dehydration synthesis
• D. Both A and c

Explanation: Because dehydration synthesis is the combination of smaller molecules into the larger molecule with the removal of water.This process involves the combination of monomers or smaller subunits to form a polymer while eliminating a water molecule. This is called condensation too

4454. Percent amount of carbohydrates in a bacterial cell:

• A. 4
• B. 3
• C. 2
• D. 1

Explanation: 3 percent amount of carbohydrates is present in a bacterial cell.

4455. What kind of Glycosidie linkage is found in sucrose?

• A. 1,6
• B. 1,4
• C. 2,6
• D. 1,2

Explanation: "The explanation for this question will be added soon!".

4456. Which of the following does not contain amino acids?

• A. Carbonic anhydrase
• B. Glycogen
• C. Haemoglobin
• D. Insulin

Explanation: Glycogen is a complex carbohydrate and a form of energy storage in animals, including humans. It is often referred to as animal starch because of its similarity to starch, which is the storage form of carbohydrates in plants. Glycogen is primarily stored in the liver and muscles, and it serves as a readily available source of glucose for the body's energy needs. Glycogen is a polysaccharide composed of many glucose molecules linked together in a branched structure. It is a highly branched molecule, which allows for quick and efficient breakdown when the body requires glucose.

4457. The number of OH groups in glucose is:

• A. 4
• B. 5
• C. 6
• D. 7

Explanation: The number of -OH groups in glucose is 5.

4458. Monosaccharide's are major components of:

• A. DNA, ATP, Ribulose bisphosphate and Cysteine
• B. DNA, NAD and Insulin
• C. DNA, NADP, ATP and Ribulose bisphosphate
• D. DNA. RNA and Myosin

Explanation: DNA is a double-stranded molecule that encodes genetic information in cells.DNA provides the instructions for building and maintaining living organisms, passing genetic information from one generation to the next.ATP is a nucleotide composed of adenosine (adenine + ribose) and three phosphate groups. It serves as the primary energy currency in cells.NADP is a coenzyme that participates in redox reactions in cells. It consists of two nucleotides, nicotinamide adenine dinucleotide phosphate.Ribulose Bisphosphate (RuBP) is a sugar phosphate involved in the Calvin cycle, a part of photosynthesis.

4459. Both glucose and fructose are hexoses, glucose makes a _whereas fructose make a_in a solution, respectively:

• A. Pyran, Pyran
• B. Furan, Furan
• C. Furan, pyran
• D. Pyran, Furan

Explanation: "Furan" is a term used in organic chemistry to refer to a heterocyclic compound that consists of a five-membered ring containing four carbon atoms and one oxygen atom. The structure of furan is a closed ring, with the oxygen atom at one of the carbon positions. Pyranose refers to a six-membered ring structure containing five carbon atoms and one oxygen atom. This ring structure is commonly found in sugars, especially in the context of carbohydrates like glucose and fructose.The pyranose ring structure is a cyclic form formed through the reaction of a carbonyl group (such as in an aldose or ketose sugar) with a hydroxyl group on another carbon atom within the same molecule.

4460. The specific heat of vaporization of water is_ Kcal/kg.

• A. 374
• B. 474
• C. 574
• D. 674

Explanation: The specific heat of vaporization of water is 574 Kcal/kg.