Plant tissues, organs and systems Flashcards
Name the parts of the plant
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Name the tissues of a plant
Epidermal tissue
Palisade mesophyll tissue
Spongy mesophyll tissue
Phloem tissue
Xylem tissue
What does the Epidermal tissue do
The epidermal tissue covers plants and protects them.
What does the Palisade mesophyll tissue do
The Palisade mesophyll contains chloroplasts for photosythesis
What does the spongy mesophyll do
Spongy mesophyll contains some chloroplast but it has large air spaces for diffusion (to allow for gases to diffuse in and out of cells)
What type of tissues are xylem and phloem tissues
Xylem and phloem tissues are the transport tissues in plants
What does the xylem tissue do
Xylem carries water and dissolved minerals from the roots to the leaves
What does the phloem tissue do
Phloem carries dissolved food from the leaves around the plant.
State the organs in a plant
Leaf, fruit, flower, stem and root are the organs in a plant
What do the root, stem and leaves form
The roots, stem and leaves form an organ system for the transport of substance around the plant.
Where is the meristem tissue found
Meristem tissue is found at the growing tips of roots and shoots
What does the meristem tissue do
The meristem tissue at the growing tips of roots and shoots is made up of rapidly dividing plant cells that grow and differentiate into all the other cell types needed.
Give the adaptation of the upper epidermis
The upper epidermis is transparent. This allows light to pass through to the photosynthetic cells below.
The upper epidermis is covered with a thin layer of oily material called the waxy cuticle. The waxy cuticle reduces the evaporation of water from the surface of the leaf. This helps to prevent the leaf from drying out.
Fill in gap
The lower epidermis has tiny pores called _____
What are the tiny pores found on the lower epidermis called
The lower epidermis has tiny pores called stomata
What do stomata do
Stomata allow carbon dioxide to enter the leaf and oxygen to leave
Stomata also help to control the amount of water vapour that can pass out of the leaf
Fill in the gap
On either side of the stomata there are _____
On either side of the stomata there are guard cells
What do the guard cells do
The guard cells control the opening and closing of the stomata.
Why are cells in the spongy mesophyll big
These cells have a big surface area for gas exchange
Why do many plant cells have many chloroplasts
Plant cells have many chloroplasts for photosynthesis
What do the epidermal cells often secrete
The epidermal cells often secrete a waxy substance that waterproofs the surface of the leaf.
Fill in the gap
Palisade mesophyll contains ______ cells
Palisade mesophyll contains palisade cells
What is the adaptation of palisade cells
Palisade cells are packed full of chloroplasts.
Chloroplasts contain chlorophyll which absorbs the light energy needed for photosynthesis
What is the key feature of the spongy mesophyll
The spongy mesophyll is full of air spaces.
The air spaces allow carbon dioxide to diffuse from the stomata through the spongy mesophyll to the palisade cells.
Oxygen also diffuses from the palisade cells through the spongy mesophyll to the stomata
What is translocation
Translocation is the movement of dissolved sugars from the leaves to the rest of the plant
Describe the process of translocation
Phloem tubes are made of columns of elongated living cells with small pores in the end walls to allow cell sap to flow through
The cell sap transports food substances (mainly dissolved sugars) made in the leaves to the rest of the plant for immediate use (for example in growing regions) or for storage
The transport goes in both directions
This process is called translocation.
What are phloem tubes made up of
They are made up of tubes of elongated cells
What are xylem tubes made up of
It is composed of
hollow tubes strengthened by lignin adapted for the
transport of water in the transpiration stream.
What are xylem tubes adapted for
Xylem tubes are adapted for the transport of water in the transpiration stream
Why is transport important
It is vital to move the food made by photosynthesis around the plant as al the cells need sugars for respiration as well as for providing materials for growth.
The movement of water and dissolved mineral ions from the roots is equally important as the mineral ions are needed for the production of proteins and other molecules within the cells
Why does the plant need water
Plants need water for photosynthesis - which is the process in which carbon dioxide and water combine to make glucose and oxygen.
The plant also needs water to hold itself upright. When a cell has plenty of water inside it, the vacuole presses the cytoplasm against the cell walls. This pressure of the cytoplasm against the cell walls gives support for young plants and for the structure of leaves.
This is the main method of support for young plants and soft-stem leaves
The changes in the mean width of the stomata in normal conditions are
an advantage to the plant.
Why is the stomata closed at midnight
But widest at midday.
How is this an advantage
stomata (almost) closed at midnight because there is no / less light for photosynthesis
This reduces/
prevents water loss
stomata open widest at midday as maximum light intensity for photosynthesis
The stomata open wide to take in most / more carbon dioxide for
photosynthesis
The changes in the mean width of the stomata in low atmospheric carbon dioxide
are different from the changes in normal conditions.
Explain how the difference helps the plant to survive in low atmospheric
carbon dioxide.
Stomata are open wider and for more time
This allows the plant to take in more carbon dioxide for
photosynthesis
Explain why the mean width of stomata is widest for a longer amount of time at midday, when in low atmospheric co2 than in normal conditions
