Plant Body Flashcards
What are the two parts of the plant body?
Shoot and root systems
Shoot System
above ground. includes organs like leaves, buds, stems, flowers, fruits and leaves
Root System
below ground. anchors the plant absorbs water and mineral nutrients, storage and transport
Plant Cell differences from animal cells
One large central vacuole (storage), chloroplasts (photosynthesis), cell wall (structure)
What are the three basic types of cells
Parenchyma, Collenchyma, Sclerenchyma
Describe Parenchyma
Flexible, thin walled, spherical. Cell wall flattens when packed together. Have many chloroplasts which produce glucose via P.S. In roots and fruits they lack chloroplasts but have larger vacuoles to store starch and water. Forms the bulk of non-woody plants (ex. fleshy part of apple)
Functions of Parenchyma
Storage, P.S. (Photosynthesis), gas exchange, protection and tissue repair/replacement
Describe Collenchyma
Long strings; elongated cells occurring in strands or cylinders (ex. celery). Cell wall expands as the cell grows. It allows plants to bend but not break.
Function of Collenchyma
Provide support
Describe Sclerenchyma
Very thick secondary cell walls. Contain lignin -makes cell wall tough and hard. There are two types, Fibres and Sclereids.
Functions of Sclerenchyma
Primarily supports. Dies when completed growth and development, leaving empty box-like structures.
Fibres
Cells up to 50cm long that usually occur in strands like linen and flax
Sclereids
Thicker cell walls and may be single or groups of cells. Give pears their gritty texture, hardness to peach pits and walnut shells.
What are the four main types of Plant Tissue and what do they do?
Meristematic, Dermal, Ground, and Vascular tissue. Produce 3 organs of a plant: roots, stem, and leaves.
Meristematic Tissue
Undifferentiated embryonic plant tissue from which all other plant tissue develops.
M.Tissue Primary Growth
Located at tips of roots and stems (Apical Meristem), causes root and stems to grow larger. Tissue found along the stem and at the base of leaf blades are Intercalary Meristem.
M.Tissue Secondary Growth
Increases circumference of roots and stems, strengthens and provides support for taller growth. Occurs at Lateral Meristems.
What are the two types of Lateral Meristems
Vascular Cambium and Cork Cambium (outer bark of trees / protective layer)
What are the two types of Dermal Tissue?
Epidermal Tissue (epidermis) and Peridermal Tissue (Periderm).
Epidermal Tissue
Outer layer: includes cuticle, a waxy covering that reduces evaporation/predation
Peridermal Tissue
Only in woody plants for protection and support(bark=dead cells)
Types of Specialized Epidermal Tissue
Guard cells, Trichomes, Root Hairs
Guard Cells
Control opening/closing stomata for gas exchange
Trichomes
Tiny growths on surface of epidermis that may cool plant, reduce evapouration; secrete sticky/toxic substances that repel herbivores; have spikes that physically puncture the skin of the herbivore
Root Hairs
Tiny extentions of epidermal cells on roots which increase the surface area for absorption of water and nutrients
Ground Tissue
Contains all three cell types (p,c,s) and forms most of plant internal/external material. Has a wide range of functions including storage of starch, support and PS
What is Vascular Tissue
Internal system of tubes that run lengthwise throughout stem to connect roots and leaves. Two types: xylem and phloem.
Function of Vascular Tissue
To transport water and dissolved substances throughout the plant and to support the stem.
Xylem
Transports water and minerals from root to leaves. When mature they die leaving tubes for transport. Two types, Tracheids and Vessel Elements.
Tracheids
Most vascular plants. Long, thin, tapered ends. Water moves cell to cell through pits
Vessel Elements
Wider, shorter. Perforation in ends, water flows freely through perforation plates.
Phloem
Transports nutrients (eg. sugar) from source to growth areas or to roots for storage. Two types Sieve Tube Elements and Companion Cells.
Sieve Tube Elements
Living parenchyma. Long narrow cells stacked end to end, pores end in walls (sieve plates).
Companion Cells
Adjacent to every sieve tube element.
