BIOLOGY - Response and regulation Flashcards
what does auxin mean
plant hormone involved in phototropism
what is benedict’s solution
chemical reagent used to test for glucose
what is blood plasma
the liquid part of blood that carries soluble substances around the body
what is diabetes
a condition which a persons blood glucose may rise to a fatally high level because the body does not produce enough insulin
• a condition
• persons blood glucose may rise to a fatally high level
• due to body not producing enough insulin
what is the effector
muscle glands that respond to stimuli
what are enzymes
biological catalysts that help to speed up the rate of chemical reactions (metabolism) in the body
what is evaporation in terms of sweat thing
• the process of water in sweat changing to water vapor
• it uses some body heat, cooling the body
what is glucagon
• protein hormone made by pancreas
• regulates blood glucose levels
• converts stored glycogen back into glucose
what is glycogen
• a substance stored in the liver and muscles
• is converted into glucose as the body requires energy for metabolism
what is gravitropism
the growth movement in a plant in response to the direction of gravity
what is homeostasis
when the body maintains constant optimal conditions in the body e.g. temperature, water levels in blood and glucose concentration
what are hormones
chemical (protein) messengers carried in the blood, which control many body functions
what are impulses
electrical signals carried by neurones (nerve cells)
what is insulin
• protein hormone made by pancreas
• regulates blood glucose levels
• converts excess glucose into glycogen
what is metabolism
the chemical process that occurs within a living organism in order to maintain life
what is negative feedback
a process in which a change in a factor, such as blood glucose level, brings about processes which change its level back towards normal again.
• a process which a change in factor
• e.g. blood glucose levels
• start processes to change level back to normal
what is a neurone?
what it do?
2 types of neurones + info?
• a nerve cell,
• they carry electrical impulses through body
• sensory neurones carry info from receptors to CNS
• motor neurones carry info from CNS to effectors
what is pancreas
a body organism that makes the hormone insulin
what is phototropism
the growth movement in a plant in response to the direction of light
what are receptor cells, and where are they found
cells that detect changes in the environment . found in sense organs
what is reflex action
fast, automatic responses to a stimulus. Has a protective function
what is a relay neurone
a neurone that transmits an impulse from a sensory neurone to a motor neurone
whats a sense organ
organs that collect info about the environment (internal and external) and send it to the CNS
what is a stimulus
a change in the environment that the body reacts to
what is thermoregulation
the process of the body controlling its internal temperature
what is tropism
a directional growth response of a plant to a stimulus
what is the role of the nervous system
to control and co-ordinate the senses and responses in the body
give an example of receptor cells and what they detect
tastebuds, detect chemicals in food
what is a nerve
a bundle of nerve fibres
nerve cells dont touch each other, a small gap is present, what is this gap called
synapse
describe how the nervous system works
1) stimulated receptors send nerve impulses
• along a sensory neurone to CNS
2) CNS co-ordinates the best response to the stimulus
3) sends electrical impulses
• along the motor neurone to effector
• which carries out the response
what is the term for when a plant grows towards the stimulus
positive tropism
where do plants grow towards and why
the light, for more photosynthesis
what is the advantage of positive phototropism in shoots
allows more photosynthesis
whichever way a seed is planted, the root always grows which way? and what tropism does it show
downwards (this shows positive gravitropism in roots)
what is the advantage of positive gravitropism in roots
can get water and minerals from soil
which part of the shoot is sensitive to light
the tip
what are the 5 parts of the eye and functions
-sclera
• protective, tough white outer coat
-cornea
• clear part of sclera
• allows light to enter
• refracts light entering
-iris
• coloured part of eye
• contains muscles that alter the size of the pupil
• control amount of light entering the eye
-pupil
• hole in the center of the eye
• lets light enter the eye
-lens
• changes shape to focus light onto the retina
What are the 4 other parts of the eye and functions
-choroid
• pigmented layer
• absorbs light to prevent reflection
• prevents light being detected several times
• Also contains blood vessels.
-retina
• light sensitive layer (photoreceptor cells) that detect light
• an image is formed here
-blind spot
• where the optic nerve leaves the eye
• there are no light sensitive cells here.
-optic nerve
• carries electrical impulses from retina to the brain
what happens when you shine light near the eye
and when there is no light
when shining light = pupils go smaller
when theres no light = pupils dilate
list some reflex actions
gag reflex
pupil size
flinching
which part of the eye could be damaged if the pupil size did not change in bright light
retina
what is the function of the co-ordinator
ensures the appropriate motor neurone is stimulated
suggest why in the withdrawal reflex, the spinal cord is involved but the pupil and blinking reflexes involve the brain
goes to whichever part of the CNS is closest for faster response
list 3 factors your body needs to keep constant
temperature
water
pH
chemical reactions in the cells produce waste products such as?
and where do they enter and afterwards?
urea and carbon dioxide
enter through tissue fluid and absorbed back into blood at the venous end of the capillary.
at the arterial end of the capillary, some parts of the plasma are forced out of the leaky capillaries, this fluid bathes the body cells and carries substances such as:
glucose and oxygen
what can too little water and too much water cause
too little = bodily fluids too concentrated and damage the body
too much = dilutes body fluids
what chemical allows the concentration of our body fluids to be maintained within safe limits?
hormones
what is the main fluid of the body
glucose
whats the word equation for aerobic respiration
oxygen + glucose ——-> carbon dioxide + water
on a hot day how is your urine production affected, and explain why
• less volume and more concentrated
• cuz more water lost as sweat, so to compensate, less water lost in urine to avoid dehydration.
what monitors the blood/glucose concentration
cells in the pancreas
what is type 1 diabetes caused by
-body overreacting to a virus, with result that the immune system destroys its own insulin producing cells in pancreas.
-possibly genetic
• just say immune system destroys its own insulin producing cells in pancreas
what is treatment for type 1 diabetes
-insulin injections
-low sugar/carbs diet
-metformin tablets
what is type 2 diabetes caused by
-old age is a common cause
-diet high in carbs/sugar
-obesity
what is treatment for type 2 diabetes
-insulin injections
-low carbs/sugar diet
-metformin tablets
what are symptoms of diabetes
-glucose present in urine
-uncontrollable blood glucose levels
-feeling tired
what is type 1 diabetes
when your pancreas doesnt produce insulin
what is type 2 diabetes
• pancreas still produces some insulin
• liver cells do not properly respond to the insulin produced
why should a diabetic person not eat a lot of sugary foods
they cant regulate their blood glucose concentration
what happens if a diabetic person gets injected with too much insulin
their blood glucose concentration would fall too low
what is the term for when someones blood glucose concentration falls too low
hypoglycaemia
what are all the parts of a vertical section through the skin
hair
sweat pore
epidermis
sweat duct
Capillaries
sweat gland
fat cells
oil gland
receptor cells
erector msucles
what do the receptor cells in the skin do
detect the temperature and send chemical impulses along sensory neurons to the brain
what happens if the body temperature goes above or below the optimum temperature of 37 degrees
brain sends messages to skin to carry out corrective mechanisms to get the body back to normal
what corrective mechanisms take place when you get too hot
sweat glands make more sweat, sweat travels up sweat duct and out of sweat pore onto the skin surface. Sweat evaporates from skin surface, increasing the cooling rate. body doesnt shiver.
erector muscle relaxes and hair flattens. less insulating air is trapped next to skin, so less insulation.
body vessel diameter widens .more blood flows to skin surface so more heat is lost by radiation. Cooling rate increases.
what corrective mechanisms take place when you get too cold
shivering - skin muscles contract and relax rapidly producing heat, warming up the blood. Body doesnt sweat
erector muscle contracts and hair strands. More insulating air is trapped next to skin so more insulation.
blood vessel diameter shrinks. less blood flows to skin surface so less heat is lost by radiation, cooling rate decreases.
what are stimuli detected by
receptor cells
there must be a reposnse that reverses stimuli. what are these responses made by
effectors
name 2 parts of the body that alcohol is absorbed through into the blood stream
stomach
small intestine
your body cells absorb alcohol and oxidise it, releasing heat, what happens to the heat
heat radiates from skin
oxidation of alcohol produces water as a waste product, this is excreted by the skin as sweat, what effect does this have on body fluids
decrease in body fluids - causes dehydration
is alcohol a depressant or a stimulant
depressant
what 4 effects does alcohol have on the nervous system
-slows reaction
-increase reaction time
-judgment is impaired
-loss of concentration
why do some people think that there should be a zero limit if you are driving for alcohol
Why do some people think that you should’ve even have any mg of alcohol before driving?
effects of alcohol start even at low levels
alcohol can be addictive, what does this mean
dependance and cravings, they need alcohol to function normally
name the liver disease that is caused by excessive, prolonged drinking of alcohol
cirrhosis
name another body organ that can be affected by the excessive alcohol consuption
heart
whats pros and cons of aspirin use
pro - pain killer
con - risk of stomach ulcers
name an illegal drug and the effect on the body
cocaine
effects such as
can make you feel happy or confident
increases your energy
can make you paranoid
drugs change various chemical processes in people’s bodies so that they can become dependent on them, what term is used to describe this dependance
addiction
when someone tries to give up a drug theyr dependant on, they can suffer symptoms, like cravings for nicotine and poor concentration, whats the term for these symptoms called
withdrawal symptoms
