Unit 1 - Lesson 9: Plant Leaves Flashcards
What is the typical green leaf called?
Foliage leaf
What are the 2 parts of a leaf?
Petiole and leaf blade
What is the function of the leaf blade?
Photosynthesis
What are the functions of the petiole?
Supporting the leaf blade in the stem, passageway for water and nutrients between stem and leaf blade, moves leaf into best position for receiving sunlight and is the location where leaf vascular tissue connects to stem vascular tissue.
What does the cuticle look like and where is it found?
A waxy layer on the epidermis (produced by epidermal cells)
What is the function of the cuticle?
Reduces water lost by transpiration
Where is the epidermis found?
The outermost layer of cells covering the leaf
What is the function of the epidermis?
Protective barrier against water loss, infection and injury. Also regulates gas exchange.
Describe the palisade mesophyll and their location.
Tightly packed parenchyma cells with many chloroplasts. Located just under the upper epidermis.
What is the function of the palisade mesophyll?
Most photosynthesis happens here because of its ideal location (just below epidermis) and shape to receive the maximum exposure to light.
Describe the vascular bundles. What are the three components?
Tube-like tissues made up of the xylem, phloem and cambium.
What is the function of the xylem?
Transport water and dissolved mineral throughout plant (moves up from roots)
What is the function of the phloem?
Transports nutrients throughout plant (moves in all direction, otherwise stored in roots)
Describe the spongy mesophyll.
Irregular shaped and loosely packed parenchyma cells containing fewer chloroplasts than the palisade mesophyll
What is the function of the spongy mesophyll?
Large air spaces between the cells allow gases to exchange through diffusion and move more freely
Describe the guard cells.
A pair of cells that surround the stoma
What is the function of the guard cells?
Regulates the opening and closing of the store to control gas exchange and water loss.
What is the stoma?
Tiny pores on the surface of leaves
What is the function of the stoma?
Facilitates gas change and regulates water loss through transpiration
Is a leaf a tissue, an organ or an organ system and why?
A leaf is an organ because it is made up of tissues.
Why is a transparent cuticle important for plants?
It allows light to penetrate tissues that do photosynthesis while still acting as a barrier against water loss
Why is it advantageous for the palisade mesophyll to be more tightly packed?
Allows for more chloroplasts in a small area, leaf can absorb more sunlight, maximizes photosynthesis and produces more energy
