Biological Molecules
Each subtopic includes About section, revision page link, 10 preview questions, and practice CTAs.
Carbohydrates, lipids and proteins
SubtopicCarbohydrates, lipids and proteins under Biological Molecules for Grade 12 IGCSE.
Preview questions (no answers)
- 1.
What color is iodine solution when no starch is present?
A.Blue-black
B.Pale blue
C.Yellow-brown
D.Violet
- 2.
Which of these functional groups is found in every amino acid?
A.Phosphate group
B.Carboxyl group ()
C.Glucose group
D.Iron group
- 3.
Which form of carbohydrate is typically transported through the phloem of a plant?
A.Starch
B.Glucose
C.Sucrose
D.Glycogen
Download the worksheet for Biological Molecules - Carbohydrates, lipids and proteins to practice offline. It includes additional chapter-level practice questions.
Structure of DNA
SubtopicStructure of DNA under Biological Molecules for Grade 12 IGCSE.
Preview questions (no answers)
- 1.
Which molecule provides the template for the synthesis of proteins, based on its own sequence?
A.Lipid
B.DNA
C.Glucose
D.Starch
- 2.
What is the result of the twisting of the two polynucleotide chains around each other?
A.A straight ladder
B.A single strand
C.A double helix
D.A triple helix
- 3.
The genetic information is stored in which of the following?
A.The sugar molecules
B.The phosphate groups
C.The order of the nitrogenous bases
D.The thickness of the helix
Download the worksheet for Biological Molecules - Structure of DNA to practice offline. It includes additional chapter-level practice questions.
Chemical tests for nutrients
SubtopicChemical tests for nutrients under Biological Molecules for Grade 12 IGCSE.
Preview questions (no answers)
- 1.
Which of the following results indicates the presence of a reducing sugar after heating with Benedict's solution?
A.A violet solution
B.An orange-brown precipitate
C.A blue-black solid
D.A milky-white emulsion
- 2.
A student tests a sample of vegetable oil. Which test should they use and what is the observation?
A.Iodine test; blue-black color
B.Biuret test; purple color
C.Emulsion test; cloudy white layer
D.Benedict's test; brick-red precipitate
- 3.
Why is it necessary to use a clear extract of food when performing the DCPIP test?
A.To prevent the food from reacting with the DCPIP
B.To ensure the fat is removed first
C.To clearly see the disappearance of the blue color
D.To make sure the Vitamin C is not destroyed
Download the worksheet for Biological Molecules - Chemical tests for nutrients to practice offline. It includes additional chapter-level practice questions.