BIOLOGY AQA GCSE PAPER 2 (TRIPLE) (HIGHER)
What is homeostasis?
-regulation of internal conditions of a cell or organism to maintain optimum conditions for
function, in response to internal and external changes
how is homeostasis controlled
by negative feedback loop
what changes does homeostasis monitor
- blood glucose concentration
-body temperature
-water levels
How dose negative feedback work?
- receptors detect a stimulus (change in environment)
- this information is collected and processed by the co-ordination center ( e.g. brain or spinal
cord)
- the response is carried out by the effector (muscles or glands) to maintain optimum conditions
what are the two types of homeostatic responses
nerves and hormones
Compare nerves and hormones
- Nerves very fast action, but act for a very short time. They act on a precise area
-Hormones slower action, but act for a very long time. They act in a more general way
how dose the nervous system work
-receptor cells (e.g. skin), pass info along neurons as electrical impulses to reach the CNS
- CNS (brain & spinal cord) coordinates the response of effectors (muscles or glands).
What is a synapse?
Gap between neurons
how dose an electrical impulse cross the synapse
- neurotansmitters diffuse across the gap and bond to the second neurone, triggering another
electrical impulse
how dose a reflex reaction occur
, - stimulus is dected by receptor
- receptor genetrates electrical impulse, that pases along the sensory neurone to the relay
neurone (in spinal column)
- the relay neuron relays impulse to motor neuron which passes it to the effector
what is the method for investigating the effect of caffeine on reaction time
ruler drop test
- use the same hand
-rest arm on table while hand over the edge
- partner holds the ruler vertically above your hand with zero mark level with your thumb
- partner drops ruler with out warning, for you to catch
-convert reading from ruler to reaction time
- repeat the investigation with diffrent doses of caffiene
what are the control variables for the above investigation
- we should limit amount of times we repeat the test so not to allow nervous system to improve
reaction time
- using the same gender
-using people with the same experince to the test
how else can we test for peoples reaction time
- using a computer program, were every time an object appears the candidtes press it
what are the 5 brain tissues
- cerebral cortex
-cerebellum
-medulla
-pituitary gland
-hypothalamus
what is the function of the cerebral cortex
Controls consciousness, intelligence, memory and language
what is the function of the cerebellum
(conscious) controls muscular co- ordination
what is the function of the medulla
(inconscious) controls heartbeat and breathing
What is homeostasis?
-regulation of internal conditions of a cell or organism to maintain optimum conditions for
function, in response to internal and external changes
how is homeostasis controlled
by negative feedback loop
what changes does homeostasis monitor
- blood glucose concentration
-body temperature
-water levels
How dose negative feedback work?
- receptors detect a stimulus (change in environment)
- this information is collected and processed by the co-ordination center ( e.g. brain or spinal
cord)
- the response is carried out by the effector (muscles or glands) to maintain optimum conditions
what are the two types of homeostatic responses
nerves and hormones
Compare nerves and hormones
- Nerves very fast action, but act for a very short time. They act on a precise area
-Hormones slower action, but act for a very long time. They act in a more general way
how dose the nervous system work
-receptor cells (e.g. skin), pass info along neurons as electrical impulses to reach the CNS
- CNS (brain & spinal cord) coordinates the response of effectors (muscles or glands).
What is a synapse?
Gap between neurons
how dose an electrical impulse cross the synapse
- neurotansmitters diffuse across the gap and bond to the second neurone, triggering another
electrical impulse
how dose a reflex reaction occur
, - stimulus is dected by receptor
- receptor genetrates electrical impulse, that pases along the sensory neurone to the relay
neurone (in spinal column)
- the relay neuron relays impulse to motor neuron which passes it to the effector
what is the method for investigating the effect of caffeine on reaction time
ruler drop test
- use the same hand
-rest arm on table while hand over the edge
- partner holds the ruler vertically above your hand with zero mark level with your thumb
- partner drops ruler with out warning, for you to catch
-convert reading from ruler to reaction time
- repeat the investigation with diffrent doses of caffiene
what are the control variables for the above investigation
- we should limit amount of times we repeat the test so not to allow nervous system to improve
reaction time
- using the same gender
-using people with the same experince to the test
how else can we test for peoples reaction time
- using a computer program, were every time an object appears the candidtes press it
what are the 5 brain tissues
- cerebral cortex
-cerebellum
-medulla
-pituitary gland
-hypothalamus
what is the function of the cerebral cortex
Controls consciousness, intelligence, memory and language
what is the function of the cerebellum
(conscious) controls muscular co- ordination
what is the function of the medulla
(inconscious) controls heartbeat and breathing
