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Molecular Biology

Each subtopic includes About section, revision page link, 10 preview questions, and practice CTAs.

Molecules to metabolism

Subtopic

Molecules to metabolism under Molecular Biology for Grade 12 IB.

About Topic & Revision

Preview questions (no answers)

  1. 1.

    Which of the following is a primary difference between starch and cellulose?

    A.

    Starch is a protein, cellulose is a carbohydrate

    B.

    Starch uses alpha-glucose, cellulose uses beta-glucose

    C.

    Starch is found in animals, cellulose is found in plants

    D.

    Starch contains nitrogen, cellulose does not

  2. 2.

    What happens during a catabolic reaction in terms of energy?

    A.

    Energy is always required to be absorbed

    B.

    Energy is released

    C.

    Energy is neither absorbed nor released

    D.

    Energy is created from nothing

  3. 3.

    Which functional group is found at the end of every fatty acid chain?

    A.

    Hydroxyl

    B.

    Amino

    C.

    Carboxyl

    D.

    Phosphate

Download the worksheet for Molecular Biology - Molecules to metabolism to practice offline. It includes additional chapter-level practice questions.

Water

Subtopic

Water under Molecular Biology for Grade 12 IB.

About Topic & Revision

Preview questions (no answers)

  1. 1.

    Which of the following is a non-polar molecule used for comparison with water in IB Biology?

    A.

    Ethane

    B.

    Methane

    C.

    Glucose

    D.

    Ammonia

  2. 2.

    Which bond is considered relatively weak individually but strong when present in large numbers in water?

    A.

    Triple covalent bond

    B.

    Hydrogen bond

    C.

    Ionic bond

    D.

    Double covalent bond

  3. 3.

    Which property of water allows it to be an effective transport medium in plants and animals?

    A.

    Its high boiling point

    B.

    Its solvent properties

    C.

    Its transparency

    D.

    Its lack of color

Download the worksheet for Molecular Biology - Water to practice offline. It includes additional chapter-level practice questions.

Carbohydrates and lipids

Subtopic

Carbohydrates and lipids under Molecular Biology for Grade 12 IB.

About Topic & Revision

Preview questions (no answers)

  1. 1.

    In plant cells, where is starch typically stored?

    A.

    In the cell wall

    B.

    In the mitochondria

    C.

    In chloroplasts or amyloplasts

    D.

    In the nucleus

  2. 2.

    What defines a molecule as 'organic' in biology?

    A.

    It contains carbon atoms

    B.

    It is only found in the air

    C.

    It cannot be synthesized in a lab

    D.

    It does not contain hydrogen

  3. 3.

    One gram of lipid contains approximately how much energy compared to one gram of carbohydrate?

    A.

    The same amount

    B.

    Half the amount

    C.

    Double the amount

    D.

    Ten times the amount

Download the worksheet for Molecular Biology - Carbohydrates and lipids to practice offline. It includes additional chapter-level practice questions.

Proteins

Subtopic

Proteins under Molecular Biology for Grade 12 IB.

About Topic & Revision

Preview questions (no answers)

  1. 1.

    The R-group of the amino acid Glycine is a single Hydrogen atom. Which of the following is true?

    A.

    It is the most complex amino acid

    B.

    It is the simplest amino acid

    C.

    It cannot form peptide bonds

    D.

    It is only found in plants

  2. 2.

    Which protein is involved in the clotting of blood?

    A.

    Fibrin

    B.

    Hemoglobin

    C.

    Albumin

    D.

    Amylase

  3. 3.

    Which statement about protein denaturation is true?

    A.

    It is always reversible

    B.

    It usually results in the loss of biological activity

    C.

    It strengthens the protein's bonds

    D.

    It only happens to fibrous proteins

Download the worksheet for Molecular Biology - Proteins to practice offline. It includes additional chapter-level practice questions.

Enzymes

Subtopic

Enzymes under Molecular Biology for Grade 12 IB.

About Topic & Revision

Preview questions (no answers)

  1. 1.

    Which of the following is a characteristic of allosteric enzymes?

    A.

    They only have one binding site

    B.

    They can be regulated by molecules binding to sites other than the active site

    C.

    They are always inactive

    D.

    They do not consist of amino acids

  2. 2.

    Why does a competitive inhibitor NOT change the maximum possible rate of a reaction?

    A.

    Because it binds to the allosteric site

    B.

    Because high substrate concentrations outcompete the inhibitor for the active site

    C.

    Because it speeds up the enzyme's movement

    D.

    Because it eventually turns into a substrate

  3. 3.

    What is the typical result of feedback inhibition in a cell?

    A.

    To produce as much product as possible quickly

    B.

    To regulate and prevent the overproduction of a substance

    C.

    To use up all available enzymes

    D.

    To increase the temperature of the cell

Download the worksheet for Molecular Biology - Enzymes to practice offline. It includes additional chapter-level practice questions.

Structure of DNA and RNA

Subtopic

Structure of DNA and RNA under Molecular Biology for Grade 12 IB.

About Topic & Revision

Preview questions (no answers)

  1. 1.

    What is the role of Uracil in Molecular Biology?

    A.

    It pairs with Guanine in DNA

    B.

    It replaces Thymine during RNA synthesis

    C.

    It acts as the sugar in the RNA backbone

    D.

    It is a purine found in both DNA and RNA

  2. 2.

    Which of these statements about the DNA double helix is correct?

    A.

    The strands are held together by covalent bonds between bases

    B.

    The two strands are identical in sequence

    C.

    The two strands are complementary to each other

    D.

    The sugar-phosphate backbone is on the inside of the helix

  3. 3.

    DNA is a polymer of which of the following monomers?

    A.

    Amino acids

    B.

    Nucleotides

    C.

    Monosaccharides

    D.

    Fatty acids

Download the worksheet for Molecular Biology - Structure of DNA and RNA to practice offline. It includes additional chapter-level practice questions.

DNA replication, transcription and translation

Subtopic

DNA replication, transcription and translation under Molecular Biology for Grade 12 IB.

About Topic & Revision

Preview questions (no answers)

  1. 1.

    What is the name of the process that converts the sequence of bases in mRNA into a sequence of amino acids?

    A.

    Transcription

    B.

    Translation

    C.

    Replication

    D.

    Splicing

  2. 2.

    What is the term for the set of three bases on a tRNA molecule that is complementary to an mRNA codon?

    A.

    Triplet

    B.

    Anticodon

    C.

    Intron

    D.

    Exon

  3. 3.

    Which molecule carries the genetic information from the DNA in the nucleus to the ribosome in the cytoplasm?

    A.

    tRNA

    B.

    rRNA

    C.

    mRNA

    D.

    DNA Polymerase

Download the worksheet for Molecular Biology - DNA replication, transcription and translation to practice offline. It includes additional chapter-level practice questions.

Cell respiration

Subtopic

Cell respiration under Molecular Biology for Grade 12 IB.

About Topic & Revision

Preview questions (no answers)

  1. 1.

    What change would you observe in a respirometer containing germinating seeds if the temperature were increased (within a normal range)?

    A.

    The rate of oxygen consumption would decrease

    B.

    The rate of oxygen consumption would increase

    C.

    The seeds would stop respiring immediately

    D.

    The amount of CO2CO_2 absorbed by the alkali would decrease

  2. 2.

    Which of the following is produced during glycolysis in addition to pyruvate and ATP?

    A.

    NADH

    B.

    Acetyl CoA

    C.

    FADH2FADH_2

    D.

    Oxygen

  3. 3.

    What is the role of ATP in a living cell?

    A.

    To store genetic information

    B.

    To provide an immediate source of energy for cell processes

    C.

    To act as a structural component of the cell wall

    D.

    To catalyze the reaction of photosynthesis

Download the worksheet for Molecular Biology - Cell respiration to practice offline. It includes additional chapter-level practice questions.

Photosynthesis

Subtopic

Photosynthesis under Molecular Biology for Grade 12 IB.

About Topic & Revision

Preview questions (no answers)

  1. 1.

    Why is the rate of photosynthesis low in the green part of the spectrum?

    A.

    Green light has too much energy

    B.

    Green light is mostly reflected or transmitted by chlorophyll

    C.

    Green light is used only for respiration

    D.

    Green light cannot penetrate the leaf cuticle

  2. 2.

    Which pigment is the main reaction center pigment in both photosystems?

    A.

    Chlorophyll a

    B.

    Chlorophyll b

    C.

    Beta-carotene

    D.

    Xanthophyll

  3. 3.

    Which of the following is an endergonic process in plants?

    A.

    Cellular respiration

    B.

    Photosynthesis

    C.

    Digestion of starch

    D.

    Diffusion of oxygen

Download the worksheet for Molecular Biology - Photosynthesis to practice offline. It includes additional chapter-level practice questions.