Unit 4.2 Plant tissues, organs and organ systems Flashcards
Epidermal tissue function is
covers the plant
Palisade mesophyll tissue function is
trap sunlight for photosynthesis - packed full with chloroplasts
Spongy mesophyll tissue function is
contains lots of air spaces to allow gases to diffuse in and out of cells
Xylem function
to transport water from the roots up and down the plant
Phloem function
to transport glucose from the leaves up and down the plant
Translocation…
Is the mass movement of sugars up and down the plant
Meristem tissue function
found at the growing tips (shoots and roots) and can differentiate into lots of different types of plant cells
Upper epidermis tissue function is
transparent so that light can pass through
Stomata function is
composed of 2 guard cells - this allows the gases to diffuse into and out of the leaf
The phloem tubes are made up of
elongated living cells
Xylem tubes/vessels are made up of
dead cells
Define the transpiration stream
movement of water from the roots, through the xylem and out of the stomata
Transpiration is
the evaporation of water from the leaves of a plant via its stomata
Transpiration is fastest when it is
windy, dry air, sunny and warm
Transpiration is slow when it is
cold, dark, humid and not windy
How can you estimate the rate of transpiration?
By measuring the rate of water uptake using a potometer
Name the cell that makes up the stomata
guard cells
How do guard cells respond when there is plenty of water available?
they become turgid and the stomata open
How do guard cells respond when there is not a lot of water available?
they shrink and become flaccid and the stomata close
How do they stomata respond to the dark
they close to conserve water
Which side of a leaf do you find more stomata
underside
Why is there fewer stomata on the upper surface of a leaf?
because it is sunnier and warmer - having less stomata reduced water loss
why is the upper epidermis transparent?
to allow light to pass through
What type of cells is the xylem made from ?
dead cells
Xylem tubes are strengthened by what material?
lignin
The movement of water from the roots up the stem and out through the leaves is called the…
transpiration stream
This word describes the evaporation and diffusion of water from the leaf via the stomata
transpiration
Phloem tubes are made up from what type of cell?
living cells
In a plant is glucose transported down the plant OR up and down the plant?
up AND down
The movement of glucose up and down the plant is called?
translocation
At night time what happens to the stomata?
they close (as no need to take in carbon dioxide)
In the night what process happens in the plant?
respiration ONLY
In the daytime what processes occur inside the plant?
Photosynthesis AND respiration
In the daytime how do the stomata respond?
they open
In dry conditions what happens to the stomata of a plant?
they become flaccid so that the stomata pore closes
Why does the stomata close in dry conditions?
reduce water loss
Which side of the leaf do you find the fewest number of stomata?
upper side
Why are there fewer stomata on the upper surface of the leaf
warmer and sunnier
Why are there more stomata on the under side of the leaf?
its cooler and in the shade
Equation for photosynthesis (word equation)
water + carbon dioxide = glucose and oxygen
How is the glucose used by the plant?
make cellulose store as starch used in respiration used to make amino acids which make proteins used to make fats and oils
