nutrition and transport in flowering plants 🪴 Flashcards
(19 cards)
What is the primary function of the leaf?
Photosynthesis
The leaf also forms other food substances such as fats and proteins.
What are the external features of a typical green leaf?
Leaf blade and leaf stalk
The leaf blade is flat, and the leaf stalk holds the leaf away from the stem.
What is the role of veins in a leaf?
Carry water, mineral salts, and manufactured food
Veins supply cells in the leaf blade and transport food to other parts of the plant.
How does the structure of the leaf blade aid in photosynthesis?
Large flat surface allows maximum light absorption
A thin leaf blade enables rapid carbon dioxide diffusion to inner cells.
How are leaves arranged around the stem?
In pairs or singly in an alternate arrangement
This arrangement prevents leaves from blocking each other and ensures adequate light.
What is the significance of the leaf stalk?
Holds the leaf blade away from the stem for light and air access
Some plants, like grasses and maize, may lack a leaf stalk.
Fill in the blank: The leaf is sometimes referred to as one of the principal factories of the world because it is where ______ occurs.
photosynthesis
True or False: The leaf blade is thick to maximize carbon dioxide absorption.
False
A large, thin leaf blade allows for rapid gas exchange.
What is the upper epidermis of a leaf made up of?
A single layer of closely packed cells
The upper epidermis is covered by a waxy and transparent cuticle.
What is the main site of photosynthesis in the leaf?
Mesophyll
The mesophyll lies just between the upper and lower epidermis.
What are the two types of tissue that make up the mesophyll?
- Palisade mesophyll
- Spongy mesophyll
Describe the palisade mesophyll.
Consists of one or two layers of closely packed, long and cylindrical cells containing numerous chloroplasts
Specialised for photosynthesis.
Describe the spongy mesophyll.
- Contains cells with an irregular shape
- Has numerous large intercellular air spaces
- Carries out photosynthesis but contains fewer chloroplasts than palisade mesophyll
- Cells covered with a thin film of moisture
- Contains transport tissue (xylem and phloem)
What is the function of the cuticle on the leaf?
Reduces water loss through epidermal cells
The cuticle covers the cells of both the upper and lower epidermis.
What are stomata?
Minute openings in the lower epidermis
Singular: stoma.
What role do guard cells play in the leaf?
Regulate the rate of transpiration by opening and closing the stoma
Guard cells contain chlorophyll, unlike other epidermal cells.
Fill in the blank: The lower epidermis consists of a single layer of _______.
closely packed cells
What is the vascular bundle in the mesophyll composed of?
Xylem and phloem
These transport tissues are grouped together within the mesophyll.
