Hormones Flashcards
(24 cards)
What are hormones
Hormones are chemicals released directly into the blood, they are carried in the blood plasma and travel slowly to other parts of the body but only affect target cells. They have long lasting affects
What do hormones do
Hormones control things in organs and cells that need constant adjustment
Where are hormones produced
In the glands.
What is the source, role and affect of adrenaline
Source: adrenal glands
Role: readies the body for a fight or flight response
Effect: increases heart rate, blood flow to muscles and blood sugar levels
What is the source, role and effects of insulin
Soucre: pancreas
Role: helps control blood sugar levels
Effect: stimulates liver to turn glucose into glycogen for storage
What is the source, role and effects of testosterone
Source: testes
Role: main male sex hormone
Effect: promotes male secondary sexual characteristics e.g facial hair
What is the source, role and effect if progesterone
Source: ovaries
Role: supports pregnancy
Effects: maintains lining of uterus
What is the source, role and effect of oestrogen
Source: ovaries
Role: main female sex hormone
Effects: controls the menstrual cycle, and promotes secondary sexual characteristics e.g widening of the good
What is the source, role and effect of ADH
Source:pituitary gland
Role: controls water content
Effect: increases the permeability of the kidney tubules to water
What is the source, role and effect of FSH
Source: pituitary gland
Role: female sex hormone
Effect: causes egg to mature in ovary, stimulates ovaries to produce oestrogen
What is the source, role and effect of LH
Source: pituitary gland
Role: female sex hormone
Effect: stimulates the release of an egg from an ovary
What are the differences between nerves and hormones
Nerves: act fast, last short time, act on precise areas
Hormones: slow message, last a long time, act in general areas
How do plants respond to changes in the environment
They sense direction of light and grow towards it to maximise light absorption for photosynthesis
They sense gravity so their roots grow in the right direction
Climbing plants have a sense of touch so they can find things to climb and reach the sunlight
How can plants respond to prescience of predators
Plants like white clover can produce substances that are toxic to cattle so the plant can avoid being eaten.
What are the plant growth hormones
Auxins
What do auxins do
Control growth at the tips of shoots and roots
They move through plants in solution dissolved in water
Promotes growth in the shoot but inhibits growth in the roots
Where is auxin produces
In the tips
How does auxin diffuse
Backwards to stimulate cell elongation process which occurs in cells behind the tips
What happens when a shoot tip is exposed to light
It accumulates more auxin on the side that’s in the shade which makes the cells grow faster on the sided shade so the shoot bends towards the light.
What does positively phototropic mean
Shoots grow towards light
What does negatively geotropic mean
Shoots grow away from gravity y
What happens when a shoot is growing sideways
Gravity produces an unequal distribution of auxin in the tip with more auxin in the lower side so the lower side will grow faster and bend the shoot upwards
What does positively geotropic mean
Roots grow towards gravity
What does negatively phototropic mean
Grows away from light
