Neurones and synapses Samenvattingen, Aantekeningen en Examens

What is homeostasis? The regulation of the conditions inside your body and cells to maintain a stable internal environment, in response to changes in both internal and external conditions Name three coordination centres The brain, the spinal cord and the pancreas What is negative feedback? When your body brings the level of something (e.g. water or temperature) back to normal if it becomes too high or too low What detects a stimulus? A receptor, e.g. skin receptors detec...

AQA GCSE Biology - Paper 2 Graded A+ What is homeostasis? The regulation of the conditions inside your body and cells to maintain a stable internal environment, in response to changes in both internal and external conditions Name three coordination centres The brain, the spinal cord and the pancreas What is negative feedback? When your body brings the level of something (e.g. water or temperature) back to normal if it becomes too high or too low What detects a stimulus? A receptor, e...

AQA GCSE Biology - B5 What is homeostasis? The regulation of conditions inside the body to maintain a stable internal environment in response to changes in both internal and external conditions What things do automatic control systems regulate? Body temperature, blood glucose level and water content What are the three main components that work together in automatic control systems? Receptors, coordination centres and effectors What does negative feedback do? When the level of some...

negative tropisms - Answer-growth away from a stimulus Define homeostasis - Answer-Homeostasis is the regulation of internal conditions in the body. It is necessary to maintain optimal conditions for body functioning. These internal conditions can change as a result of processes within the body and as external conditions change. systems responsible for homeostasis - Answer-the nervous system - uses electrical impulses to communicate the endocrine system - uses chemical molecules to commun...

AQA GCSE Biology Topic 5 Homeostatis Homeostasis The maintenance of a constant internal state in a changing environment Why is homeostasis important? Homeostasis is important because it is essential for the survival of cells and enzymes Automatic control systems are made up of Receptors, coordination centres, effectors negative feedback a mechanism of response in which a stimulus initiates reactions that reduce the stimulus Receptor Detects change Coordination centre Receives an...

Describe the events of fertilisation that occur after the acrosome reaction. -Membrane of sperm and egg cell fuse together -cortical granules release contents into zona pellucida -Zona pellucida thickens -Haploid nuclei fuse Explain how phospholipids form a cell surface membrane -Hydrophilic parts associate with water -Hydrophobic parts repel water -a bilayer forms with hydrophobic parts pointing in towards the centre of the bilayer Describe the role of the CFTR protein in e...

AQA GCSE Biology topic 5 - Homeostasis and Response Homeostasis maintaining a stable environment e.g. nervous and hormonal communications, body temp, blood glucose levels. negative feedback A process that counteracts a change - increasing and decreasing levels to maintain homeostasis, e.g. sweating to lower the body temp the nervous system A system that manages the body through negative feedback, hormones and effectors made up of Central nervous system (CNS - brain + spinal cord), se...

homeostasis A tendency to maintain a balanced or constant internal state; the regulation of any aspect of body chemistry, such as blood glucose, around a particular level nervous system A conglomeration of billions of cells specifically designed to provide a communication network within the human body. receptors Special structures that allow living organisms to sense the conditions of their internal or external environment stimuli Changes, occurring within or outside the body, that affect...

AQA GCSE Biology - The Nervous System What does the nervous system enable humans to do? React to (their) surroundings (and) coordinate their behaviour What is the central nervous system? Brain and spinal chord What do your brain and spinal chord make up? C(entral )N(ervous )S(ystem) What are stimuli? Changes in the environment What are receptors? Cells detecting stimuli What is a nerve impulse? (An) electrical message Where does a nerve impulse travel? (Along a) neurone What is...

AQA BIOLOGY ESSAY TITLES VERSION 2 Biology essay titles Version 2 This document contains the essay titles and mark schemes used in AQA A-level Biology examinations since 2007. The specifications these exam questions came from are no longer in use, but the marking method has largely remained unchanged. Further guidance on the marking method used with the essay can be found in Paper 3 Essay marking guidance. Year Questio nTitle 7402/3 2017 7.1 The impo...