[ 2MID ] General Biology - Plant Tissues

Kingdom Plantae

includes green, brown and red algae, liverworts, mosses, ferns and seed plants with or without flowers.

Surface/Dermal Tissue

• This tissue forms the epidermis, usually one cell layer.

• covers and protects the surface of plant organs.

Stomata

The leaf opening for gas exchange

Trichomes

leaf hairs, protect against herbivores and damaging solar radiation

Root Hairs

These are slender projections in the epidermal cells of roots, which enable a cell’s modification to increase surface area of the root for absorption.

Cutin

A waxy substance that prevents water loss.

Cuticle

This protects against bacteria and other organisms that may cause harm to the plant.

Epidermis

An example of surface tissue that is also in the outer layer of leaves, stems, roots, flowers, and seeds.

Fundamental/Ground Tissue

• This forms the main bulk of plants. They fill most of the spaces in any plant organ.

• The cells that form this are involved in the production and storage of food, and serves as support for the plant.

Parenchyma

• most abundant, carry out photosynthesis, store protein and starch

• This best represents a typical plant cell.

• They are large, thin-walled, and usually have a large central vacuole. They usually contain plastids.

• This is capable of cell division and could give rise to more specialized cells, such as when roots develop from stem cuttings placed in water.

Collenchyma

• elongated, thick cell walls, areas of active growth

• This functions mainly as support. Similar in structure with parenchyma except that they have a thicker cell wall.

Sclerenchyma

• thick cell walls reinforced with lignin, programmed cell death, cell walls remain to provide support

• These are nonliving and function as a support to the mature parts of the plant.

Vascular Tissue

• Tissue comprised of the xylem and the phloem, the main transport systems of plants.

• These are complex conducting tissues that extend from the roots to the leaves of plants.

Xylem

carries water and minerals from roots to rest of plants, composed of dead cells. one-way

Phloem

composed of living cells, moves carbohydrates from production sites to where they are either used or stored; two-way.

Permanent Tissues

Groups of cells that have lost their ability to divide (differentiated) and are specialized for specific functions. They are classified into simple permanent tissues (parenchyma, collenchyma, sclerenchyma) and complex permanent tissues (xylem and phloem). These tissues provide support, transport nutrients, and perform various metabolic activities essential for plant growth and survival.

Meristematic Tissues

• consist of actively dividing cells responsible for growth. They are found in specific regions like the tips of roots and shoots (apical meristem), along the sides of stems and roots (lateral meristem), and at the base of leaves or nodes (intercalary meristem). These tissues help in primary and secondary growth, enabling plants to increase in size and develop new organs.

• are undifferentiated because their cells remain actively dividing and do not yet have specialized functions.

Cambium

A ring of meristematic tissues found inside a mature stem, which allows growth in diameter or increase in the thickness of stems or roots.

Vegetative Organs

These are organs that allow the plant to live and grow.

Root

This anchors the plant to the soil for support and absorbs water and minerals from the soil.

Stem

The main axis of the plant together with its branches. It functions as a support and for the transport of water and nutrients absorbed by the roots to the leaves.

Leaves

These are the chief organs of plants for photosynthesis and responsible for the manufacture of food.

Flowers, fruits, and seeds

These are the organs involved in reproduction. All these plant organs are made up of groups of similar cells with a common function (plant tissues).

Guard Cells

These are modified epidermal cells found on leaves that function to open or close the stomata.

Meristems

These are made up of embryonic tissues called meristematic tissues. This is the part of the plant where growth is the fastest.

Apical Meristems

These are found in the tip of the stems or roots that allow these organs to grow longer.

Lateral Meristems

These are found on the nodes of stems and are involved in the formation of branches.

Vascular Cambium

A type of cambium that produces new layers of vascular tissues.

Cork Cambium

A type of cambium that produces new layers of surface tissue called cork.

False; thin-walled, no central vacuole

MODIFIED TRUE OR FALSE.

The cells found in Meristematic Tissues are usually small, thick-walled, and with central vacuole.

Mitosis

The main function of meristematic tissues is to undergo cell division called _______.

Carbon Dioxide

What diffuses into the stomata during daytime?

Oxygen

What diffuses out of the stomata during daytime?

Cork

• An example of surface tissue that covers the outer surface of the bark of woody stems and roots. It is made up of dead cork cells that may be sloughed off.

• This protects the plant from mechanical injury.

Fibers

A type of sclerenchyma cell that is long and slender.

Sclereids

A type of sclerenchyma cell that is irregular in shape.

Lignin

An organic substance that makes the cell wall tough and hard.

Tracheids

These are elongated, hollow, and noliving cells with tapered ends. Water and minerals can pass between this through the pits or depressions found in its end walls.

Vessel Elements

These are hollow and nonliving, but are larged and without end walls. These form a continuous pipeline of water and minerals from the roots to the leaves.

Sieve Tube Members

These are elongated cells with few organelles and no nucleus.

Stoma

A Greek word that means “mouth,” that is why the stomata looks like tiny mouths.

Terminal Bud

This produces new leaves and other tissues during primary growth.

Lateral Bud

a small growth located at the junction between a leaf and the stem (in the leaf axil). It has the potential to develop into a branch, flower, or shoot.

Node

This is where the leaf or leaves are attached to the stem.

Internode

The region in between the nodes is ________

Fibrous Roots

the opposite of a taproot system. It is usually formed by thin, moderately branching roots growing from the stem. This is universal in monocotyledonous plants and ferns.

Taproot

a large, central, and dominant root from which other roots sprout laterally. Typically this is somewhat straight and very thick, is tapering in shape, and grows directly downward.

Adventitious Roots

These arise from an organ other than the roots, such as the stem or a leaf. This is the reason why you can propagate plants from stem or leaf cuttings.

Root Cap

The tip of the root is round in shape and covered with a structure called ____ ___.

Periderm

a protective tissue that is formed during secondary growth in the stems, branches and roots of most dycotyledons and gymnosperms.