Biology (Plant Tissues)

Parenchyma, Collenchyma, Sclerenchyma

Classifications of Ground tissues

Ground Tissues

Includes all tissues that are neither dermal nor vascular. Fills the space between them and carry out metabolic functions.

Photosynthesis, Storage of food, water, and waste, Healing and regenaration ofplant tissues

3 Functions of Parenchyma

Parenchyma

Thin-walled, living cells, loosely packed

Collenchyma

Unevenly thickened cell walls, living cells

Provides mechanical support and flexibility, Provides growth without breaking

2 Functions of Collenchyma

Sclerenchyma

Dead cells with very thick lignified walls

Fibers, Sclereids

Two types of Sclerenchyma

Provides strength, rigidity, and protection, Makes plant parts hard and woody

2 Functions of Sclerenchyma

Dermal Tissue

Simple permanent tissue. Outermost layer or “skin” of the plant

Epidermis, Periderm

2 Main types of Dermal tissue

Epidermis

Shield most important tissues beneath

Periderm

Secondary growth of plant tissue. Replacement of epidermis

Cuticle

Thin, waxy layer

Trichomes

Tiny, hair-like structures

Stoma

Tiny pores

Guard cells

Bean-shaped cells

Root Hairs

Microscopic tubular extensions of root

Cork

Outer protective layer

Cork Cambium

Merismatic layer

Phelloderm

Food and nutrient storage

Cuticle

Prevent water from escaping, and invasion of pathogens. Extra protection

Trichomes

Gas and nutrient transfer. Deter insects

Stoma

Exchange of water and gases

Guard Cells

Regulate opening and closing of stomata. Control gas exchange an water loss

Root hairs

Absorb water, minerals, and nutrients. Anchor the plant. Increase surface area

Cork

Waterproofing, protects against pathofens, injuries, and extreme temperatures.

Cork Cambium

Maintains secondary growth

Vascular Tissue

Lifelines of plants. Responsible for transporting water, minerals, and nutrients throughout the plant structure.

Xylem, Phloem

Main Types of Vascular Tissue

Xylem

Responsible for transporting nutrients and water upwards direction.

Tracheids, Vessel elements, Xylem Parenchyma, Xylem fibers

Cell types in xylem

Tracheids

Long, narrow cells with tapered ends

Vessel elements

Wider and shorter cell with perforated ends

Xylem Parenchyma

Involves various metabolic functions.

Xylem Fibers

Elongated and dignified. Give structural support

Phloem

Responsible for transporting sugar produced in photosynthesis to the entire plant, upward and downward direction.

Sieve Tube Elements, Companion cells, Phloem Parenchyma, Phloem fibers

Cell types in Phloem

Sieve tube elements

Main functional cell of the phloem, elongated, tube-like and has sieve like plates that let sugars pass through.

Phloem Parenchyma

Store and assist in transport

Phloem Fibers

Long and slender cell that provides structural support.

Transpiration

Water and minerals are transported to vessels due to this process

Translocation

Phloem functions through a process called ______