B1.2 Coordination and Control Flashcards
Define ‘receptors’.
A cell that can detect stimuli.
Define ‘stimuli’.
Changes in the environment.
State what the receptors in the eyes are sensitive to.
Light.
Which body part coordinates a response when it receives information?
The brain.
What are the tongue and nose sensitive to and what does this allow us to do?
Chemicals.
Taste and smell.
What does ‘CNS’ stand for?
Central Nervous System.
What does the CNS include?
The brain and spinal cord.
why is it important for animals to detect changes in their surroundings
so they can avoid danger
light receptor cells contain?
nucleus, cytoplasm & cell membrane
what are the 2 main parts of the CNS?
spinal cord and brain
what type of cell carries information to and from the CNS
neurone cell
how do impulses get across synapses
signal is transferred across the gap by chemicals which are released. Chemicals diffuse across the gap and trigger a new impulse in the neurone on the other side - electrical impulses
where are hormones produced
the glands
what are the differences between hormones and the nervous system
hormones- slower, don’t target specific areas
CNS- short amount of time, target specific areas
where is FSH & LH produced
pituitary glands
where is oestrogen produced
ovaries
what are two functions of FSH?
causes egg to mature in an ovary
stimulates the ovaries to produce oestrogen
what is the function of LH
stimulates release of egg from ovary
what effect does oestrogen have on the production of FSH
inhibits the production of FSH
how do FSH and LH increase ferility
stimulates egg release in women’s ovaries
what does the combined pill contain? what are the advantages?
oestrogen and progesterone
reduces risk of cancer
very effective
how does oestrogen reduce fertility
gives high levels of it in the blood. Stops FSH so egg development stops so none are released during the menstrual cycle
how has the combined pill changed?
lower levels of oestrogen because it was causing blood clots
where are auxins produced on a plant?
tips of the roots and shoots
what is homeostasis
the maintenance of a constant internal environment in the body
why do humans become ill if our body temperature isn’t 37 degrees
enzymes controlling all reactions in the human body don’t work as well
what part of the body monitors your body temperature?
the brain
what causes the blood sugar level to drop
person may have done exercise
why does the body’s blood sugar levels need to be constantly maintained
provide body’s cells with a constant supply of energy
why would someone’s urine by more concentrated on a hot day?
more swear so more water would be lost through skin and less through urine - ion concentration would be higher
name the plant hormone that stimulates growth?
auxin
where do auxins grow?
tips of the roots and shoots
what do plant shoots grow towards?
light and against gravity
what do plant roots grow towards?
moisture and gravity
what do auxins control?
phototropism - light
gravitropism - gravity
what did scientists do to test if this was real about plant auxins?
they cut of the roots shoots tips and they did not grow towards the light - therefore proving it’s auxins
what side of the shoot do auxins concentrate on? this means what?
the darker side so the cells on the darker side grow faster causing it to bend towards the light
what side to auxins grow on the roots? this means that?
the lower side as auxins inhibits cell growth so the lower side grows more slowly - roots grow towards gravity
