1 Diagram 1 shows an organism. Which of the following A, B, C and D is dorsal? flag bookmark A A B B C C D D T4 Chapter 1.3 Communicating in Biology The dorsal side is the back (upper) surface of an animal. Label B points to the upper surface along the animal's back, so B is dorsal; the opposite (lower) surface is ventral.
2 The following statements are the characteristics of component R. - Has a double membrane - Interior contains aqueous solution that has enzyme - Site for aerobic respiration What is component R? flag bookmark A Vacuole B Chloroplast C Ribosome D Mitochondrion T4 Chapter 2.1 Cell structure and function A double membrane, an inner fluid (matrix) containing enzymes and being the site of aerobic respiration are all features of the mitochondrion. Chloroplasts also have a double membrane but they carry out photosynthesis, not respiration.
3 Table 1 shows the density of organelle X in two types of cells. | Type of cell | Density of organelle X (%) | |---|---| | Liver cell | 65 | | Flight muscle cell | 20 | What is the function of organelle X? flag bookmark A Form spindle fibres B Secretes mucus to protect the mucous membranes C Transports synthesised enzymes D Produces energy in the form of ATP T4 Chapter 2.1 Cell structure and function Liver cells make and send out many enzymes and proteins, so they have far more of organelle X than flight muscle cells. This fits the rough endoplasmic reticulum, which transports the proteins (enzymes) made by ribosomes. ATP production (D) would be highest in flight muscle, not liver.
4 Diagram 2 shows a process of absorption of substance Q into plant root hair cells. This absorption process requires energy. What is substance Q? flag bookmark A Water B Sodium ion C Oxygen D Glucose T4 Chapter 3.3 Movement of Substances Across a Plasma Membrane in Living Organisms The absorption needs energy, so it is active transport. Root hair cells take up mineral ions such as sodium ions by active transport against the concentration gradient. Water and oxygen move passively, and glucose is not absorbed from the soil.
5 Diagram 3 shows the set-up of apparatus prepared by a student to study the movement of water molecules by osmosis. Which of the following steps can be used to lower the level of coloured liquid solution in potatoes? flag bookmark A Replacing distilled water with a 20% sucrose solution B Replacing distilled water with a 40% sucrose solution C Replacing a coloured 20% sucrose solution with a 30% sucrose solution D Replacing a coloured 20% sucrose solution with a 40% sucrose solution T4 Chapter 3.2 Concept of Movement of Substances Across a Plasma Membrane Water moves by osmosis from a dilute solution to a more concentrated one. If the distilled water outside is replaced with a 40% sucrose solution, which is more concentrated than the 20% solution inside, water leaves the potato and the coloured liquid level falls.
6 The sequence of nitrogenous bases in a nucleotide chain in a segment of DNA molecule is AATTCCGG. What is the sequence of nitrogenous bases in the nucleotide chain beside this chain (double helix chain)? flag bookmark A ATCTATCG B CCGGAATT C AATTCCGG D TTAAGGCC T4 Chapter 4.5 Nucleic Acids In DNA, adenine pairs with thymine and cytosine pairs with guanine. So the complementary strand of AATTCCGG is TTAAGGCC.
7 Which of the following are the characteristics of enzymes? I Structure of enzymes are changed at the end of a reaction. II Enzymes are only required in small amounts. III The action of enzymes is specific. IV Reactions catalysed by enzymes are irreversible only. flag bookmark A I and II B II and III C III and IV D I and IV T4 Chapter 5.2 Enzyme Enzymes are needed only in small amounts (II) and each enzyme acts only on a specific substrate (III). Enzymes are not changed at the end of the reaction (I is wrong), and many enzyme reactions are reversible (IV is wrong).
8 Diagram 4 shows the mechanism of enzyme action. Which of the following is P? flag bookmark A Substrate B Active site C Enzyme D Enzyme-substrate complex T4 Chapter 5.2 Enzyme P is the part of the enzyme where the substrate fits and binds, which is the active site.
9 What is the process involved in nuclear division? flag bookmark A Meiosis I B Meiosis II C Cytokinesis D Karyokinesis T4 Chapter 6.1 Cell Division Nuclear division is called karyokinesis. Cytokinesis is the division of the cytoplasm, which follows nuclear division. (Note: the answer scheme gives C; on checking, our AI thinks D is more accurate, so both C and D are accepted.)
10 Diagram 5 shows a cell at one particular stage of meiosis. Which of the following is the final result produced by the cell division of the cell? flag bookmark A B C D T4 Chapter 6.3 Meiosis The cell shows homologous chromosomes in pairs, so it is in meiosis I. At the end of meiosis (after meiosis II) four haploid daughter cells are produced, each with one chromosome from each pair.