Transportation in detail Flashcards
Where does gas exchange take place?
The lungs
What is the job of the lungs?
How do the lungs do this?
To transfer oxygen to the blood and to remove waste CO2 from it
They contain millions of tiny air sacks called alveoli where gas exchange takes place
How are alveoli specialized to maximise diffusion of oxygen and CO2? (4)
They have: an enormous surface area a moist lining for dissolving gases very thin walls a good blood supply
What do villi provide?
Where are they found?
A very large surface area for digestion
On the inside of the small intestine
What do villi do?
Describe them in 3 points… (they look like bristles sticking out of a brush)
They increase the surface area of the intestine so that the digested food is absorbed much more quickly into the blood
They have a single layer of surface cells (between the air and the inside of the cell)
a very good blood supply to assist quick absorbtion
they are filled by a network of capillaries
What is active transport?
When a substance is absorbed against a concentration gradient through a partially permeable membrane requiring energy
What are root hair cells specialised for?
What adaption do they have for this? What does this mean?
Why are the cells needed? (simple)
Absorbing water and minerals
The cells on the surface of the plant root grow into long hairs so they stick out into the soil.
It gives the plant a big surface area for absorbing water and mineral ions from the soil
- most of the minerals and ions needed come from the soil, absorbed by the root hair cells
How do root hair cells absorb substances?
Why?
What does active transport allow?
What’s bad about it though?
What other type of living thing does active transport? - what do they transport?
Active transport
The concentration of minerals is usually higher inside the cell so normal diffusion doesn’t work.
The plant can absorb minerals from a very dilute solution against a concentration gradient, essential for growth.
It requires energy from respiration to work.
Humans transport glucose from the gut and from kidney tubules.
Where is active transport used in the body? Why?
What happens to glucose and amino acids when there’s a high concentration in the gut?
Low concentration?
In the gut - there is a low concentration of nutrients here but a high concentration in the blood
They diffuse naturally into the blood
The concentration gradient is the wrong way so active transport allows nutrients to be taken into the blood
What are the two types of vessel that transport things around the whole of the plant?
What do phloem transport?
Xylem?
Xylem and Phloem
Food
Water upwards into the plant
What are phloem tubes made from? Describe their shape..
What do they transport?
And in which direction?
Columns of living cells with small holes in the ends (like a sieve) to allow substances to flow through.
They are rounded cylindrical tubes with mesh bottoms, green
Food substances (mainly dissolved sugars) made in the leaves to the growing regions like shoots or to the storage organs like the root tubers.
Both directions
What are xylem tubes made from? Describe their shape..
What do they transport?
And in which direction?
Dead cells joined end to end with no end walls between them and a whole down the middle … a long hexagonal tube - brown
Water and minerals from the roots to the stems and leaves in the transpiration system
Upwards
What is transpiration?
The loss of water from a plant
What is transpiration caused by?
What does this create? Causing?
What does this mean for the roots? Causing?
The evaporation and diffusion of water form inside the leaves
A small shortage of water in the leaf so more water is drawn up from the rest of the plant in xylem vessels to replace it.
More water is drawn up from the roots causing a constant transpiration stream of water through the plant
What is the side effect of photosynthesis and why? Describe this…
Transpiration because of the way the leaves are adapted for PS.
They have to have stomata in them so that gases can be exchanged easily. Because there’s more water inside than outside the plant the water escapes through the leaves’ stomata.
