Plant Tissues, Organs And Organ Systems Flashcards
What tissues are doing in a leaf?
Upper epidermis
Palisade mesophyll
Spongy mesophyll
Lower epidermis
Xylem
Phloem
What is a tissue?
A group of specialised cells with similar structures working together to perform a common function
What is an organ?
A group of tissues that work together to perform a common function
What is an organ system?
A group of organs and that work together to perform an overall life process
What is the function of the epidermis tissue?
Covers and protects surface
Secretes a waxy substance which waterproof the leaf
What is the function of the palisade mesophyll?
Contains lots of chloroplasts which carry out photosynthesis
What is the function of the spongy mesophyll?
Contains some chloroplasts
Has big air spaces and large surface area for quick rate of diffusion of gases
What is the function of the xylem?
Carries water and dissolved minerals from roots to leaves
What is the function of the phloem?
Carried dissolved food from leaves around the plant
What is the function of the meristem tissue?
Contains stem cells which rapidly divide to differentiate into cells needed
What is the function of a root hair cell?
Uptake water by osmosis
Uptake mineral by active transport
How are root hair cells adapted?
Increase surface area
Large permanent vacuole - speed up water movement
Many mitochondria for active transport
How are xylem cells adapted?
Reinforced walls to support weight of plant
Narrow tube so sturdy water column
Spiral lignin so xylem can stretch as plant grows
How is the phloem adapted?
Many mitochondria for cells to load sugars from mesophyll cells
Siege tube elements contain little cytoplasm and no nucleus
Cross walls with pores to allow flow of sap
What is the function of a leaf?
Carries out photosynthesis
What is the function of the stem?
Support leaves and flowers
What tissues does the stem contain?
Meristem
Phloem
Xylem
Epidermal tissues
What is the function of the root?
Takes in water and minerals from soil
Anchored the plant so it doesn’t fall over
What tissues are there in roots?
Meristem at the ends
Xylem
Phloem
Epidermal
What is the function of flowers?
Sexual reproduction
What tissues are in a flower?
Xylem
Phloem
Stands
Anthems
Petal
What Is transpiration?
The loss of water vapour by diffusion from the leaves of the plant through the stomata when they are opened to allow gas exchange for photosynthesis
What is a transpiration stream?
The movement of water through a plant from the roots to the leaves as a result of the loss of water by evaporation by from the surface of leaves
What factors affect transpiration?
Higher light intensity and CO2 concentration - more stomata open for photosynthesis
Higher temperatures - more energy
Dry conditions - steep gradient
Windy conditions - maintains conc gradient
More leaves - larger surface area
