OCR A Level Biology Paper 3 (2023/2024 Priority Topics) exam 70questions and answers lates, Exams of Nursing

Download OCR A Level Biology Paper 3 (2023/2024 Priority Topics) exam 70questions and answers lates and more Exams Nursing in PDF only on Docsity! OCR A Level Biology Paper 3 (2023/2024 Priority Topics) exam 70questions and answers latest update 2023/2024 graded A+ What do plants respond to for survival? - correct answers Biotic (living) and abiotic (non-living) factors What are tropisms? - correct answers Directional growth responses in plants What 3 things can plants release for survival? - correct answers Tannins, alkaloids and pheromones What controls the growth of a plant? - correct answers Plant hormones What is the role of gibberellin? - correct answers Growth regulation and stem elongation What is the role of cytokinin? - correct answers Promoting lateral bud growth How can phototropism be investigated? - correct answers Shining light onto one side of the plant and measuring stem elongation on each side. How can geotropism be investigated? - correct answers Allowing gravity to work on one side of the experimental plant and observing root growth. What are the commercial uses of auxins? - correct answers Promotes flowering and prevents fruit dropping so fruit grows larger. Used as a herbicide to kill weeds. What are the commercial uses of cytokinins? - correct answers Delays leaf loss and used in tissue culture to mass-produce plants. What are the commercial uses of gibberellins? - correct answers Fruit production, germinating seeds in brewing beer, sugar cane elongation, speeding up plant breeding. OCR A Level Biology Paper 3 (2023/2024 Priority Topics) exam 70questions and answers latest update 2023/2024 graded A+ What are the commercial uses of ethene? - correct answers Speeds up fruit ripening and enhances lateral bud growth. Inhibiting ethene prolongs shelf life. What are the two main divisions of the nervous system? - correct answers CNS and PNS What is the CNS divided into? - correct answers Brain and spinal cord What is the PNS divided into? - correct answers Sensory system and motor system What is the motor system divided into? - correct answers Somatic nervous system and autonomic nervous system What is the autonomic nervous system divided into? - correct answers Sympathetic nervous system and parasympathetic nervous system What is the function of the cerebrum? - correct answers Sensory perception, emotions, willed movements, consciousness, and memory What is the function of the cerebellum? - correct answers Fine motor control and voluntary movement. What is the function of the hypothalamus? - correct answers Controls homeostatic measures (thermoregulation and osmoregulation) What is the function of the medulla oblongata? - correct answers Controls non- skeletal cardiac and smooth muscles OCR A Level Biology Paper 3 (2023/2024 Priority Topics) exam 70questions and answers latest update 2023/2024 graded A+ When are identical twins formed? - correct answers When a zygote or fertilised egg cell divides by mitosis, but the two daughter cells split and each divide to form a new individual. How is reproductive cloning in animals achieved? - correct answers Embryo twinning or somatic cell nuclear transfer What are the advantages of using microorganisms in biotechnology? - correct answers Cheap, low temperatures and normal pressures can be used, portable, reduces waste, short life cycle, no ethical issues. What are 4 examples of the uses of microorganisms in biotechnology? - correct answers Yoghurt, bread, alcoholic beverages and cheese What are fermenters? - correct answers Containers that optimise the conditions for the growth of microbes in large-scale medicinal drug production. What do fermenters do? - correct answers Maintain optimum temperatures for enzymes, suitable nutrient and oxygen levels for respiration, and concentration of product to maximise yield. What are pathogens? - correct answers Organisms that can cause disease by living on or in a host. What are the 4 main types of pathogen? - correct answers Bacteria, fungi, viruses and protoctists How do plants defend against pathogens? - correct answers Using passive and active mechanisms. Active mechanisms are activated on detection of pathogens. OCR A Level Biology Paper 3 (2023/2024 Priority Topics) exam 70questions and answers latest update 2023/2024 graded A+ What are the two general features of inflammation that help to minimise the impact of an infection? - correct answers An increase in blood flow to the area of infection increases white blood cell levels at the sight of infection. Excess tissue fluid will drain into the lymphatic system where it will come into contact with lymphocytes. What is the role of T killer cells (cytotoxic T cells) in the immune response? - correct answers They recognise cells that present non-self antigens on their surface and release chemicals that destroy these cells. What is the function of B memory cells? - correct answers They are long-lived cells that remain dormant in the lymphatic system. On the second meeting with their target antigen, they rapidly divide and produce antibodies, which can destroy the antigen much more quickly compared to the first exposure. When do autoimmune diseases occur? - correct answers When our own B and T cells attack our own antigens and cells. What are antigens? - correct answers Proteins found in the membrane of pathogens that trigger immune responses What are antibodies? - correct answers Proteins produced by plasma cells in the specific response. What do vaccinations do? - correct answers Introduce a weakened disease antigen to stimulate an immune response. What are vaccinations used for? - correct answers Tackling epidemics and pandemics What is herd immunity? - correct answers Vaccinating the majority of the population (80-95%) to prevent a disease spreading from person to person. OCR A Level Biology Paper 3 (2023/2024 Priority Topics) exam 70questions and answers latest update 2023/2024 graded A+ What is ring vaccination? - correct answers Vaccinating people in the immediate area of a new disease outbreak. Most effective with livestock diseases. How is natural immunity achieved? - correct answers Through life processes How is artificial immunity achieved? - correct answers Through medicine What does active immunity involve? - correct answers The activation of the immune system and the production of antibodies What does passive immunity involve? - correct answers Supplying antibodies from another source. What is natural active immunity? - correct answers Immunity produced when one is infected with the real disease and produces memory cells. What is natural passive immunity? - correct answers Antibodies provided through the placenta or breastmilk. What is artificial active immunity? - correct answers Immunity provided via vaccination. Antibodies are made in response to an injected antigen. What is artificial passive immunity? - correct answers Immunity provided by injection of antibodies from an immune individual. Why must medicines continue to be developed? - correct answers To tackle new or existing diseases and antibiotic resistance.