Biology Flashcards
What is the word equation for photosynthesis
Light
Carbon dioxide + water ————-> glucose + oxygen
What affects the rate of photosynthesis
Light intensity, concentration of co2 and the temperature.
What are the graphs for rate of photosynthesis like for light intensity, co2 and temperature
With light intensity they are directly proportional until it reaches the limit where temperature and co2 must be increased. These same goes for co2 and temp except for if the temp exceeds maximum the rate decreases
What do root hair cells have to collect water
Large surface area to volume ratios
What do phloem tubes do
They transport food
What do xYlem tubes do
These take up water
What is transpiration
The loss of water from a plant
Hat is the stomata
These are tiny pores on the surface of a plant and allow oxygen and co2 to diffuse in and out the plant
What environmental factors affect the transpiration rate
Light intensity temperature and air flow
How are leaves adapted for photosynthesis
They are board in order to absorb morelight, he palisade layer has lots of chloroplasts, the upper epidermis is transparent. The waxy cuticle prevents water loss
What are shoots
Positively phototropisch and negatively gravitropix
What are roots
Negative phototropic and negative gravitropic
What uses do plant hormone shave
Selective weed killers, growing from cuttings, controlling flower and fruit formation, producing seedless fruit, controlling fruit ripening, controlling seed germination
How do selective weed killers work
They produce auxins which disrupt their normal growth pattern.
How are hormones used in growing cuttings
This is where a small part of a plant grows by adding root powder
How do hormones control flower formation
Gibberellins are hormones which stimulate seed germination. Theses can also reduce flower formation and improve fruit quality
Where do all the hormones come from
Many hormones are from the pituitary gland, thyroxine from the thyroid gland, oestrogen from the ovaries, adrenaline from the adrenal gland, Testosteron from the testier and insulin from the pancreas
What’s the difference between neurones and hormones
Neurones are fast and act on a specific area for a short amount of time. Whereas hormones are slow act for a long time and act a general area
What does adrenaline do
This happens when you panic and starts fight or flight, it only happens when your body detects a stressful situation
What does thyroxine do
It regulates metabolism.
What happens in the four stages of the menstrual cycle
In the first stage the uterus lining breaks down. Then the uterus is repeated. An egg is released. The lining is then mainrptained.
What are the four hormones in the menstrual cycle
Fsh, lh, oestrogen, progesterone
What does fsh do
It is released by the pituitary gland and causes a follicle to mature an ovary and stimulates oestrogen production
What doe oestrogen do
Released by the ovaries, causes uterus to thicken and grow,
Stimulates lh
