Transport Systems Flashcards
Describe xylem vessels
Xylem vessels are hollow, dead tubes
What do the walls of xylem vessels contain?
Rings of tough woody lignin for support
Describe a polem vessel.
Carry dissolved food from the leaves, up and down the plant. Polem cells are alive.
What cell controls the phloem unit?
The companion cell controls the polem vessel and provides energy
Describe how polem vessels transport food.
Food is transported in the cytoplasm strands through the sleeve plants from cell to cell
Describe a root hair cell.
~ Specialised plant cells found in roots which increases the absorbing area
~ Allows water from the soul to enter the cell by osmosis
What is transpiration?
The evaporation of water through the stomata
What factors affect transpiration?
Temperature, humidity and wind speed.
What would increase the rate of transpiration?
Increasing the temperature and wind speed
What would decrease the rate of transpiration?
Increase in humidity
At the lungs…
Oxygen diffuses into the blood. Carbon dioxide diffuses into the Aveolus
At the cells…
Oxygen diffuses into the cells. Carbon dioxide diffuses Into the blood
What is digestion?
Breakdown of large insoluble food molecules into small soluble food molecules
Why is digestion important?
Allows the food molecules to pass through the small intestine/gut wall and into the blood
What is peristalsis?
Food moves along the alimentary canal due to muscular contractions
What makes peristalsis work?
Saliva must be prescient in the digestive tract?
What is the small intestine?
Long tube where end products of digestion are absorbed
What are villi’s?
Small finger like projections where absorption takes place
Name 3 advantages of the small intestine
Folded on the inside ~ gives larger surface area
Thin walls ~ allows materials to absorb easier
Villi ~ absorbs food: finger like projections gives larger surface area
Name structures of alveoli and how they help it
Very thin lining - allow faster diffusion
Surface lining is moist - gases can dissolve before they diffuse
Millions of them - larger surface area
Any food that is not digested passes into the what?
Large intestine
Describe what a xylem vessel does?
Carries water and minerals from the souls to the leaves for photosynthesis.
