Structure of plants Flashcards
What are the three main organs of a flowering plant?
Roots, stems, leaves.
What is the function of roots?
Absorb water and minerals, anchor the plant, store food.
What is the function of stems?
Support the plant, transport water (xylem) and food (phloem), store food.
What is the function of leaves?
Photosynthesis, gas exchange, transpiration.
What are the reproductive organs of flowering plants?
Flowers, seeds, and fruits.
What is the difference between monocots and dicots?
• Monocots have one seed leaf (cotyledon), parallel veins, scattered vascular bundles, and flower parts in multiples of 3.
• Dicots have two seed leaves, netted veins, vascular bundles in a ring, and flower parts in multiples of 4 or 5.
What are the four main types of plant tissues?
Dermal, vascular, ground, and meristematic tissue.
What is the function of dermal tissue?
Protection; the epidermis prevents water loss and acts as a barrier to pathogens.
Where is dermal tissue found?
Outer layer of roots, stems, and leaves (epidermis).
What is the function of vascular tissue?
Transport of water, minerals, and food. Includes xylem and phloem.
Where is vascular tissue found?
• Roots – Central vascular cylinder (stele).
• Stems – Vascular bundles (scattered in monocots, ring in dicots).
• Leaves – Veins (midrib and smaller veins).
What is the function of ground tissue?
Photosynthesis, storage, and support.
Where is ground tissue found?
• Roots – Cortex for storage.
• Stems – Pith and cortex for support and storage.
• Leaves – Mesophyll for photosynthesis (palisade and spongy layers).
What is the function of meristematic tissue?
Cell division for growth.
Where is meristematic tissue found?
• Apical meristems – Root and shoot tips (primary growth).
• Lateral meristems – Vascular cambium and cork cambium (secondary growth in dicots).
What is the structure and function of xylem?
• Made of tracheids and vessels.
• Transports water and minerals from roots to leaves.
• Provides structural support due to lignin.
What is the structure and function of phloem?
• Made of sieve tube elements and companion cells.
• Transports sugars and nutrients from leaves to the rest of the plant (translocation).
What is lignin, and where is it found?
A strengthening substance found in xylem walls.
What is the difference between tracheids and vessels in xylem?
• Tracheids – Long, narrow, with tapered ends.
• Vessels – Wider, have perforated plates, allow faster water transport.
What are sieve tube elements?
Living cells in phloem that transport food but lack nuclei.
What are companion cells?
Cells in phloem that support sieve tubes by controlling their functions.
What is the function of stomata?
Control gas exchange and transpiration in leaves.
What is the function of guard cells?
Open and close stomata to regulate gas exchange.
What is transpiration?
The loss of water vapor from leaves through stomata.
