1 What is the correct step after forming a hypothesis? flag bookmark A Collecting data B Identifying problems C Controlling variables D Planning scientific investigation T4 Chapter 1.4 Scientific Investigation in Biology The steps of a scientific investigation are: identify the problem, form a hypothesis, identify and control the variables, plan and carry out the investigation, collect data, interpret the data and draw a conclusion. So controlling variables comes right after forming the hypothesis.
2 Diagram 1 shows several cells that form a tissue. Which of the following is the correct match about the tissue and its importance? | | Type of tissue | Importance | |---|---|---| | A | Muscle tissue | Involve in voluntary movement | | B | Nerve tissue | Coordinate body activity | | C | Epithelial tissue | Covers the hollow surface | | D | Connective tissue | Involve in transport of substances | flag bookmark A Muscle tissue – Involve in voluntary movement B Nerve tissue – Coordinate body activity C Epithelial tissue – Covers the hollow surface D Connective tissue – Involve in transport of substances T4 Chapter 2.4 Levels of Organisation in Multicellular Organisms The cells in the diagram are red blood cells. Blood is a connective tissue, and it transports substances such as oxygen, nutrients and wastes around the body.
3 Table 1 shows the condition of a plant cell that is immersed in distilled water for 20 minutes and then immersed in 30% sucrose solution. Which of the following condition of the cell will be observed if the cell is immersed in distilled water for another 20 minutes? flag bookmark A B C D T4 Chapter 3.3 Movement of Substances Across a Plasma Membrane in Living Organisms In the 30% sucrose solution (hypertonic) the cell lost water and became plasmolysed. When it is put back into distilled water (hypotonic), water enters by osmosis, the vacuole swells and the cytoplasm presses against the cell wall again (deplasmolysis). The cell becomes turgid like at the start, as in A.
4 Diagram 2 shows a treatment received by a boy in hospital. Which of the following is type of the solution? flag bookmark A Isotonic B Hypotonic C Hypertonic T4 Chapter 3.4 Movement of Substances Across a Plasma Membrane and Its Application in Daily Life Saline drip is isotonic to blood plasma, so the blood cells neither gain nor lose water. A hypotonic drip would make red blood cells swell and burst, and a hypertonic one would make them shrink (crenate).
5 Which of the following characteristic of saturated fats that distinguishes them from unsaturated fats? flag bookmark A Able to receive additional hydrogen atoms B Found in liquid form at room temperature C Has double bonds between carbon atoms D Contain high low-density lipoproteins (LDL) T4 Chapter 4.4 Lipids Saturated fats have only single bonds between carbon atoms, are solid at room temperature and raise the level of low-density lipoprotein (LDL) in the blood. Accepting extra hydrogen atoms, being liquid at room temperature and having double bonds are features of unsaturated fats.
6 Which of the following step can reduce the time taken to remove stains from clothes washed with bio detergent? flag bookmark A Increase the quantity of water used B Increase the temperature of water until 40 °C C Washing clothes using dry cleaning D Reduce the concentration of bio detergent used T4 Chapter 5.3 Application of Enzymes in Daily Life Bio detergents contain enzymes such as proteases and lipases. Warm water at about 40 °C is close to their optimum temperature, so the enzymes break down the stains faster. Reducing the detergent concentration would slow the process down.
7 Diagram 3 shows the graph of the effects of temperature that influence the enzyme activity. Which of the following statement is correct? I Enzyme is denatured at 30 °C II More products formed at 40 °C III Three-dimensional shape of enzyme is maintained at optimum temperature IV More enzyme-substrate complex is formed at 50 °C flag bookmark A I and II B I and IV C II and III D III and IV T4 Chapter 5.2 Enzyme The rate of reaction is highest at about 40 °C, the optimum temperature, so most product forms there (II), and the enzyme keeps its three-dimensional shape at the optimum temperature (III). At 30 °C the enzyme is still active, not denatured, and at 50 °C the rate has fallen, so fewer enzyme-substrate complexes form.
8 Diagram 4 shows a stage during a cell division. Which of the following is the number of chromosomes in the daughter cells produced at the end of the cell division? flag bookmark A 2 B 4 C 6 D 8 T4 Chapter 6.3 Meiosis Two chromosomes, each still made of two chromatids, are being pulled to each pole. Homologous chromosomes are separating, so this is anaphase I of meiosis. Each daughter cell at the end of the division receives 2 chromosomes.
9 The following information is the characteristics of a child with a genetic disorder. - Slanted eyes - Mentally retarded - Stunted body growth What is the cause of this genetic disorder? flag bookmark A Synapsis does not occur during prophase I B Cytokinesis does not occur during telophase II C Sister chromatid does not separate during anaphase II D Nuclear membrane does not form during telophase II T4 Chapter 6.4 Issues of Cell Division on Human Health These are features of Down syndrome, caused by an extra chromosome 21. The extra chromosome comes from non-disjunction during meiosis, for example when sister chromatids fail to separate in anaphase II, so a gamete gets two copies of chromosome 21.
10 Lactic acid is accumulated in an athlete's muscles after taking part in 200 m sprint. Which of the following statement contributes to the situation? flag bookmark A Oxygen debt in the muscle has been paid B Aerobic respiration in muscle increases C Glucose oxidation in muscle increases D Lactic acid fermentation in muscle increases T4 Chapter 7.3 Fermentation During a sprint, oxygen cannot reach the muscles fast enough, so the muscle cells carry out more lactic acid fermentation to get extra energy. This produces lactic acid, which builds up in the muscles.