Homeostasis and Response - topic 5 (paper 2)

• Abstinence: Deliberately refraining from having sexual intercourse
• Accommodation: The process of changing the shape of the lens to focus on near or distant objects
• Adrenaline: A hormone that is produced by the adrenal glands in response to fear or stress which increases the heart rate and boosts the delivery of blood to the brain and muscles as a part of the ‘fight or flight’ response
• Antidiuretic hormone (ADH): A hormone that increases the reabsorption of water in the kidney tubules
• Contraception: Methods used to prevent pregnancy
• Coordination centres: Areas of the body like the brain, spinal cord and pancreas that receive and process information from receptors
• Deamination: A process occurring in the liver that removes the amino group from an amino acid to produce ammonia
• Dialysis: A method of treating kidney failure or disease where the blood is artificially filtered to remove waste and toxins
• Effectors: Muscles or glands which bring about responses which restore optimum levels
• Ethene: A type of plant hormone which controls cell division and the ripening of fruits
• Follicle stimulating hormone (FSH): A female reproductive hormone that causes the maturation of an egg in the ovary
• Geotropism/Gravitropism: A plant’s directional growth response to gravity
• Gibberellins: A type of plant hormone which initiates seed germination
• Gland: A group of cells that secrete chemicals called hormones directly into the bloodstream
• Homeostasis is the maintenance of a constant internal environment.
• Homeostasis involves mechanisms to keep optimum conditions despite internal and external changes, which are needed for enzyme action and all cell functions.
• Glucagon: A hormone produced by the pancreas that causes glycogen to be converted into glucose and released into the blood
• Homeostasis controls blood glucose concentration, body temperature, water levels, and nervous and hormonal communication is involved in the automatic control systems, which detect changes and respond to them.
• Homeostasis: The regulation of the internal conditions of a cell or organism to maintain optimum conditions for function in response to internal and external changes
• The nervous system allows us to react to our surroundings, and coordinate actions in response to stimuli.
• Hyperopia: A defect of the eye where nearby objects appear out of focus (also called long sightedness)
• Receptor cells convert a stimulus into an electrical impulse.
• The electrical impulse travels along cells called sensory neurons to the central nervous system (CNS).
• In Vitro Fertilisation (IVF): Fertilising a woman’s egg using sperm outside of the body
• In the CNS, the information is processed and the appropriate response is coordinated, resulting in an electrical impulse being sent along motor neurons to effectors.
• Luteinising hormone (LH): A female reproductive hormone that stimulates the release of an egg
• The effectors carry out the response, which may be muscles contracting or glands secreting hormones.
• Automatic responses which take place before you have time to think are called reflexes.
• Myopia: A defect of the eye where distant objects appear out of focus (also called short sightedness)
• Fruit is picked when it is not ripe.
• Another way to clone a plant is to use tissue culture.
• Gibberellins can be used to increase fruit size, as the seeds in fruit produce gibberellins to increase fruit size.
• Ethene controls ripening, it is used in the food industry.
• When fruit is needed to be sold, it is exposed to ethene and warmer temperatures.
• The cells begin to form roots and shoots.
• This reduces wastage as more fruit is suitable to be sold and it does not ripen too early.
• Gibberellins are used in the brewing industry to increase the germination rate of barley seeds, which is used to make malt.
• Cells from the plant are taken and placed in a growth medium containing lots of nutrients.
• Hormones such as auxins are added to the growth medium.
• Gibberellins can be used to promote flowering, allowing the plant to flower in any conditions and with bigger flowers.