STPM Biology 2021 Term 1 MCQ

Which is not true about the property and physiological role of water?

• A

• B

• C

• D

Which is the molecular formula for the product of the dehydration reaction of three glucose

molecules?

• C₁₈H₃₀0₁₅

• C₁₈H₃₂0₁₆

• C₁₈H₃₄0₁₇

• C₁₈H₃₆0₁₈

In gel electrophoresis, the rate of migration of DNA molecule through the gel is determined

by all of the following except _______

• the voltage supplied

• the gel length

• the net charge of the DNA

• the molecular size of the DNA

Which is the function of the smooth endoplasmic reticulum?

• Produces albumin in the cells

• Produces lysozyme found in tears

• Synthesises cholesterol in the cells

• Synthesises lipase in the small intestine

What would happen to a cell membrane if cholesterol is unable to incorporate with its

phospholipid membrane at high temperatures?

• The membrane would be too firm.

• The membrane would be too fluid.

• The membrane would be permeable to water-soluble substances.

• Toe membrane would be impermeable to lipid-soluble substances.

In the nervous system, which structure supports and insulates the neurones?

• Axons

• Nodes of Ranvier

• Dendrites

• Schwann cell

Which are true about exocytosis?

• I and II

• I and IV

• II and III

• III and IV

Which of the following represents the Michaelis-Menten constant of an enzyme for a

substrate?

• The dissociation constant of the enzyme-product complex.

• The dissociation constant of the enzyme-substrate complex.

• The substrate concentration at which the reaction rate is half maximal.

• The substrate concentration is halved at which the reaction rate is maximal.

The reaction equation of a reaction that involves a cofactor is given. Which type of cofactor is used in the above reaction?

• precursor

• ion activator

• coenzyme

• prosthetic group

Which is the importance of lactic acid production in the muscle cells during anaerobic

conditions?

• Regenerates NAD⁺

• Repays the oxygen debt

• Produces acetyl CoA

• Reduces pyruvate to lactate