1 An accident occurred in the laboratory involving a mercury spill. Which of the following is the correct steps to handle mercury spills? I Declare the spill area as a restricted zone II Sprinkle sulphur powder to cover the spill III Wipe up the spill using appropriate equipment IV Call safety department flag bookmark A I and II B I and III C II and IV D III and IV T4 Chapter 1.2 Safety and Rules in Biology Laboratory For a mercury spill, the area is first declared a restricted zone so no one walks through it (I), and sulphur powder is sprinkled over the spill because it combines with mercury to form mercury sulphide, which is less dangerous (II). Mercury should not simply be wiped up.
2 Which of the following cells have a high density of mitochondria? flag bookmark A Liver cells B Muscle cells C Guard cells D Epidermis cells T4 Chapter 2.1 Cell structure and function Muscle cells contract all the time and need a lot of energy, so they have many mitochondria to carry out cellular respiration and release energy.
3 Diagram 1 shows the movement of the dye molecules in water. What is process S? flag bookmark A Osmosis B Facilitated diffusion C Simple diffusion D Active transport T4 Chapter 3.2 Concept of Movement of Substances Across a Plasma Membrane The dye molecules spread out on their own from where they are concentrated to where they are less concentrated until they are evenly spread. This is simple diffusion; no membrane, carrier protein or energy is involved.
4 Diagram 2 shows the apparatus set up of an experiment. After one hour the visking tube containing solution R is more turgid and the size is bigger compared to the visking tube containing solution Q. What are the solutions used in this experiment? | | R | P | Q | |---|---|---|---| | A | Water | 10% sucrose solution | 25% sucrose solution | | B | 25% sucrose solution | Water | 10% sucrose solution | | C | Water | 10% sucrose solution | 25% sucrose solution | | D | 25% sucrose solution | 10% sucrose solution | Water | flag bookmark A Water – 10% sucrose – 25% sucrose B 25% sucrose – Water – 10% sucrose C Water – 10% sucrose – 25% sucrose D 25% sucrose – 10% sucrose – Water T4 Chapter 3.3 Movement of Substances Across a Plasma Membrane in Living Organisms Both visking tubes stand in solution P. Tube R swells, so water entered it by osmosis: R is hypertonic to P (25% sucrose in 10% sucrose). Tube Q shrinks, so water left it: Q is hypotonic to P (water in 10% sucrose).
5 Diagram 3 shows part of the structure of the plasma membrane of a cell, a cross section of a green leaf and the adipose tissues under the human skin. The parts labelled P, Q and R in Diagram 3 consist of different forms of lipids. What are these forms of lipid? | | P | Q | R | |---|---|---|---| | A | Fat | Phospholipid | Wax | | B | Wax | Fat | Phospholipid | | C | Phospholipid | Wax | Fat | | D | Phospholipid | Fat | Wax | flag bookmark A Fat – Phospholipid – Wax B Wax – Fat – Phospholipid C Phospholipid – Wax – Fat D Phospholipid – Fat – Wax T4 Chapter 4.4 Lipids P is the phospholipid bilayer of the plasma membrane. Q is the waxy cuticle on the leaf surface. R is the adipose tissue under the skin, which stores fat.
6 The technology of enzyme immobilisation is used in various industries. An example of the industry is the production of fruit juice. State the advantage of the technique. flag bookmark A More juice production B Juice is more nutritious C Juice is tastier and more durable T4 Chapter 5.3 Application of Enzymes in Daily Life Immobilised enzymes such as pectinase are held in place and can be used again and again in a continuous process, so more juice can be produced from the same enzyme, and the enzyme does not end up in the juice.
7 Diagram 4 shows a human life cycle. What are process X and Y? | | X | Y | |---|---|---| | A | Mitosis | Meiosis | | B | Fertilisation | Meiosis | | C | Meiosis | Mitosis | | D | Fertilisation | Mitosis | flag bookmark A Mitosis – Meiosis B Fertilisation – Meiosis C Meiosis – Mitosis D Fertilisation – Mitosis T4 Chapter 6.1 Cell Division Process X forms the ovum and sperm in the ovary and testis, so it is meiosis, which halves the chromosome number. Process Y turns the zygote into an adult by repeated cell division that keeps the chromosome number, so it is mitosis.
8 Diagram 5 shows one phase in cell division that occurs at the shoot tips. State the number of chromosomes in each daughter cell and the number of daughter cells produced after the process. | | Number of daughter cells | Chromosome number of daughter cell | |---|---|---| | A | 2 | 8 | | B | 2 | 4 | | C | 4 | 8 | | D | 4 | 4 | flag bookmark A 2 – 8 B 2 – 4 C 4 – 8 D 4 – 4 T4 Chapter 6.2 Cell Cycle and Mitosis The skema gives B: two daughter cells, each with 4 chromosomes, as the chromosomes are drawn in pairs lined up at the equator. (Note: cell division at a shoot tip is mitosis, which would give 2 daughter cells with all 8 chromosomes; see the doubts list.)
9 Cell respiration produces energy for living organisms. Which process of respiration produces carbon dioxide? flag bookmark A Lactic acid fermentation in bacteria B Lactic acid fermentation in yeast C Alcohol fermentation in yeast T4 Chapter 7.3 Fermentation Alcohol fermentation in yeast breaks glucose down into ethanol, carbon dioxide and a little energy. Lactic acid fermentation produces lactic acid only, with no carbon dioxide.
10 Emphysema is a chronic obstructive pulmonary disease (COPD) common among cigarette smokers. How is a person affected by the disease? flag bookmark A The alveolus wall is damaged B The bronchiole becomes inflamed C The bronchiole walls become swollen and thick D The elasticity of the lungs is reduced T4 Chapter 8.4 Health Issues Related to the Human Respiratory System In emphysema, the walls of the alveoli are damaged and break down, so the surface area for gaseous exchange falls and the person becomes short of breath. Inflamed, swollen bronchioles describe bronchitis and asthma.