Science Group
Explore subjects and practice MCQs
7
Chapters
1,610
Total MCQs
Science Group
Answer: Sucrose is a disaccharide, while glucose, fructose and galactose are monosaccharides.
Answer: Thyroxine is a thyroid hormone whose structure contains iodine.
Answer: DNA exists as a double helix, resembling a twisted ladder.
Answer: Cholesterol is a steroid lipid found in animal cell membranes and used to make hormones.
Answer: Fluorine helps harden tooth enamel and reduces the risk of dental caries.
Answer: Keratin is a fibrous structural protein found in skin, hair and nails.
Answer: Water is polar, so it dissolves salts, sugars and many other substances easily.
Answer: DNA consists of two strands wound around each other to form a double helix.
Answer: Sodium ions are essential for conducting nerve impulses and regulating fluid balance.
Answer: Adenine pairs with thymine through two hydrogen bonds in the DNA double helix.
Answer: Metabolism is the sum of all the chemical reactions taking place inside the body of an organism.
Answer: Carbon dioxide gains hydrogen and electrons (is reduced) to form glucose during photosynthesis.
Answer: Photolysis is represented as 2H2O -> O2 + 4H+ + 4e-, so two water molecules release one oxygen molecule.
1214
Answer: Catabolism breaks down complex substances into simpler ones and releases energy.
Answer: Light reactions take place in the thylakoid membranes where chlorophyll and photosystems are located.
Answer: Anabolism is the constructive phase of metabolism that builds complex molecules using energy.
Answer: The Calvin cycle occurs in the stroma, the fluid-filled region of the chloroplast.
Answer: The electron transport chain produces most of the ATP through oxidative phosphorylation.
Answer: ATP is the energy currency of the cell because it stores and releases energy for cellular work.
Answer: The dark reaction uses ATP for energy and NADPH for reducing power to fix carbon dioxide.