1 The following information is method for managing biological waste. - Packed in biohazard plastic bags - Sterilised in an autoclave - Placed into a biohazard bin Which of the following materials is disposed using these methods? flag bookmark A Blood B Syringes C Gloves D Animal carcases T4 Chapter 1.2 Safety and Rules in Biology Laboratory Used gloves are non-sharp solid biological waste. They are packed in biohazard plastic bags, sterilised in an autoclave and put in a biohazard bin. Syringes are sharp waste and go into a sharps container, and blood is liquid waste.
2 Diagram 1 shows an animal cell. What is structure P? flag bookmark A Nucleus B Chloroplast C Golgi apparatus D Mitochondrion T4 Chapter 2.1 Cell structure and function P is a stack of flattened, curved sacs with small vesicles at the edges, which is the Golgi apparatus. It modifies, packs and transports proteins and lipids.
3 Which of the following is correctly matched for the cell component and its function? | | Cell component | Function | |---|---|---| | A | Plasma membrane | Maintains the shape of the cell | | B | Cytoplasm | Maintains turgidity of the cell | | C | Ribosome | Generates energy | | D | Smooth endoplasmic reticulum | Synthesizes and transports glycerol and lipids | flag bookmark A Plasma membrane – Maintains the shape of the cell B Cytoplasm – Maintains turgidity of the cell C Ribosome – Generates energy D Smooth endoplasmic reticulum – Synthesizes and transports glycerol and lipids T4 Chapter 2.1 Cell structure and function The smooth endoplasmic reticulum synthesises and transports lipids such as glycerol and fatty acids. The plasma membrane controls what enters and leaves the cell, turgidity is kept by the vacuole, and ribosomes make proteins (mitochondria generate energy).
4 Diagram 2 shows the condition of an onion cell before and after being immersed in solution X. What is solution X and the process involved? | | Solution X | Process involved | |---|---|---| | A | Hypotonic | Deplasmolysis | | B | Hypotonic | Osmosis | | C | Hypertonic | Haemolysis | | D | Hypertonic | Plasmolysis | flag bookmark A Hypotonic – Deplasmolysis B Hypotonic – Osmosis C Hypertonic – Haemolysis D Hypertonic – Plasmolysis T4 Chapter 3.4 Movement of Substances Across a Plasma Membrane and Its Application in Daily Life After immersion the vacuole has shrunk and the cytoplasm has pulled away from the cell wall. The cell lost water by osmosis, so solution X is hypertonic and the process is plasmolysis. Haemolysis happens only to animal cells such as red blood cells.
5 A student buys mango slices and sprinkles salty plum powder on the fruit slices. After 30 minutes, he noticed that the fruit slices become soft. What causes this condition? flag bookmark A Water diffuses into the mango cells by osmosis B Water diffuses out from the mango cells by osmosis C Salt diffuses into the mango cells by facilitated diffusion D Salt diffuses out from the mango cells by active transport T4 Chapter 3.4 Movement of Substances Across a Plasma Membrane and Its Application in Daily Life The salty powder makes the surface of the mango hypertonic to the cell sap. Water diffuses out of the mango cells by osmosis, the cells become plasmolysed and lose their firmness, so the slices turn soft.
6 The main source of food for livestock is grass. What is the example of polysaccharide in the grass that provides energy to the livestock? flag bookmark A Glucose B Sucrose C Cellulose D Glycogen T4 Chapter 4.2 Carbohydrates Grass is mostly cellulose, the polysaccharide of plant cell walls. Microorganisms in the stomach of ruminants such as cows digest cellulose, so it becomes their main energy source. Glucose and sucrose are not polysaccharides, and glycogen is stored only in animals.
7 Diagram 3 shows the graph of enzyme reaction rate for enzymes J, K and L influenced by surrounding pH. Which of the following are enzymes J, K and L? | | J | K | L | |---|---|---|---| | A | Salivary amylase | Trypsin | Lipase | | B | Pepsin | Salivary amylase | Trypsin | | C | Pepsin | Lipase | Trypsin | | D | Lipase | Salivary amylase | Pepsin | flag bookmark A Salivary amylase – Trypsin – Lipase B Pepsin – Salivary amylase – Trypsin C Pepsin – Lipase – Trypsin D Lipase – Salivary amylase – Pepsin T4 Chapter 5.2 Enzyme J works best at pH 2, the acidic stomach, so it is pepsin. K works best at about pH 7, the mouth, so it is salivary amylase. L works best at about pH 8, the small intestine, so it is trypsin.
8 Diagram 4 shows prophase I of meiosis in an animal cell. What is the number of chromosomes found in the daughter cell after completing its division? flag bookmark A 2 B 4 C 6 D 8 T4 Chapter 6.3 Meiosis The cell has two homologous pairs (bivalents), so it has 4 chromosomes (2n = 4). Meiosis halves the chromosome number, so each daughter cell has 2 chromosomes.
9 The following equation shows an aerobic respiration in human muscle cells. Glucose + Oxygen → X + Y + Energy What are X and Y? | | X | Y | |---|---|---| | A | Carbon dioxide | Water | | B | Carbon dioxide | Ethanol | | C | Lactic acid | Water | | D | Ethanol | Lactic acid | flag bookmark A Carbon dioxide – Water B Carbon dioxide – Ethanol C Lactic acid – Water D Ethanol – Lactic acid T4 Chapter 7.2 Aerobic Respiration Aerobic respiration breaks glucose down completely with oxygen into carbon dioxide and water, releasing a lot of energy. Lactic acid and ethanol are products of anaerobic respiration.
10 Microorganism such as bacteria plays an important role in the fermentation process to produce yoghurt. Why does the drink taste sour? flag bookmark A Glucose is broken down into lactic acid B Lactose is broken down into lactic acid C Fructose is broken down into lactic acid T4 Chapter 7.3 Fermentation Lactobacillus bacteria ferment lactose, the sugar in milk, into lactic acid. The lactic acid makes yoghurt taste sour and makes the milk proteins thicken.