Biology Ch 23 Test

What are stems three main functions?

1.produce leaves, branches, and flowers 2. to hold leaves towards the sunlight 3. to transport substances between roots and leaves

the funtion of roots?

Absorb water and dissolved nutrients, anchor plants, protect from harmful soil bacteria, and hold plants upright.

What elements are essential plant nutirents?

CPPNM: Nitrogen, phosphorus, potassium, magnesium, calcium

Differentiation

Cells develop into mature cells with specialized structures and functions

Endodermis

Completely encloses the root's vascular subsystem in a region called the vascular cylinder

Phloem

Consist of sieve tube elements and companion cells. Responsible for food/nutrients

Xylem tissue

Consists of Tracheids and vessel elements. Transports water

Sapwood

Covers heartwood. Contains active xylem that transports water and minerals

What are the four main TISSUE systems?

Dermal (skin), Vascular (bloodstream), Ground, and Meistematic

Casparian strip

Each brick shaped cell is surrounded on four sides by a waterproof strip

Parenchyma

Ground tissue consists mainly of these cells.Cells have thin cell walls and large central vacuoules sunrrounded by a thin layer of cytoplasm. Are the site of most of a plants photosynthesis.

Early wood

Growth beggining in the spring, the vascular cambium begins to grow rapidly which produces large light colored cell walls.

Bark

Includes tissues like cork, cork cambium and phloem.

Cortex

Inside the epidermis, a spongy layer of ground tissue.

Vascular Cambium

Lateral meristimatic tissue,produces vascular tissues and increases thickness of stems over time

Tracheids

Long narrow cells with walls that are impermeable to water. When they mature, they die, and their cytoplasm disintegrates.

Mesophyll

Makes up most of a leaf, ground tissue. Photosynthesis occurs here

Apical Meristem

Near the end or tip of each growing stem and root. A group of undifferentiated cells taht divide to produce increased length of stems and roots.

What are the layers of a mature root?

Outside layer, the epidermis, and a central cylinder of vascular tissue. Between the two tissues lies a large area of ground tissue.

What 3 kind of cells make up ground tissue?

Parenchyma, collenchyma, sclerenchyma

Companion cells

Phloem cells, surround sieve tube elements. Support the phloem cells and aid in the movement of substances in and out of the phloem.

Function of leaves

Plants main photosynthetic systems, help protect against water loss

Cork Cambium

Produces the outer covering of stems. Part of stem growth

Purpose of root hairs

Provide a large amount of surface area to aid in water absorbtion

Internode

Regions between the nodes

What three ways do plants move water through their xylem tissue?

Root pressure (osmosis), capillary action, and traspiration

What are the three principal ORGANS of seed plants?

Roots, stems, and leaves

Late wood

Smaller and thicker cell walls forming a layer of dark wood, grows in winter

Why is osmosis important?

THe high concentration of mineral ions in the plant cells causes water molecules to move into the plants by osmosis

What are the two main types of roots?

Taproots (dicots) and fibrous (monocots)

Petiole

The blade is attatched to the stem by this thick stalk

Heartwood

The older xylem near the center of the stem that no longer conducts water. Usually darkens with age because it accumulates impurities that cannot be removed.

Epidermal Cells

The outer covering of a plant consists of dermal tissue, which consists of a single layer of epidermal cells.

Taproot

The primary root grows long while the secondary roots remain small

Vessel element

They mature and die before they conduct water. The cell walls at both ends are lost when the cells die, transforming the stack of vessel elements into a continuous tube where water can move freely

Cuticle

Thick waxy coating of the epidermal cells

Palisade Mesophyll

Underneath the epidermis. Layer of mesophyll cells that are closely packed and absorb light that enters the leaf

Blades

Used to collect sunlight, thin flattened sections. attatched to the stem

What is the purpose of a root system?

Water and mineral transport

Pressure flow hypothesis

When nutrients are pumped into or removed from the phloem system, the change in concentration causes a movement of fluid in that same direction. As a result, pohloem is able to move nutrients in either direction to meet the nutritional needs of a plant

Transpiration Pull

When water is lost through transpiration, osmotic pressure moves water out of the vascular tissue of the leaf, then the movement of water out of the leaf "pulls" water upwards through the vascular system all the way from the roots

What are the two subsystems in vascular tissue?

Xylem: a water conducting tissue, and Ploem: a food conducting tissue.

Sink

a cell where the sugars are used or stored

Spongy mesophyll

a loose tissue with many air spaces between its cells.

Source

any cell which sugars are produced by photosynthesis

Adhesion

attraction between unlike molecules

Fibrous roots

branch to such and extent that no single root grows larger than the rest

How does water move from the root epidermis to the cortex?

by active transport and osmosis

Function of stems?

carries nutirents, defense system, subsystems lift water from roots to the leaves to carry the products of photosynthesis from the leaves back down to the roots

Sclerenchyma

cells have edxtremely thick, rigid cell walls that make ground tissue tough and strong

Collenchyma

cells have strong flexible cell walls that helpo support larger plants. Make up the "strings" in a stalk of celery.

Meristems

clusters of tissue that are responsible for continuing growth throughout the plants lifetime.

Cork

consists of cells that have thick walls and usually contain fats, oils, or waxes. Waterproof and help prevent water loss

Buds

contain underdeveloped tissue that can produce new stems and leaves

Root cap

covers fragile new cells produced by meristem tissue. protects the root as it forces its way through the soil

Secondary Growth

growth of width. Takes place in lateral meristematic tissues called the vascular cambium and cork cambium

The major force in water transport....

is provided by the evaporation of water from leaves during transpiration.

Plants keep their stomata open....

just enough to allow photosynthesis to take place but not so much that they lose an excessive amount of water

the leafs gas exchange subsystems helps to maintain homostaseous by

keeping the water content of the leaf relitively constant. Opening the stomata (water is abundant), closing the stomata (water is scarce)

Sieve tube elements

main phloem cells, the end walls have small holes in them for the movement of materials. As they mature, they loose their nuclei and most of the other organelles in their cytoplasm. It is a pipeline where sugars and other food are carried in a watery stream

Translocation

movement of water through a plant, getting water from the ground to the leaves

Primary Growth

of stems is produced by cell divisions in the apical meristem. Takes place in all seed plants. Growth in length

Pith

parenchyma cells inside the ring of vascular tissue

What are the three leaf functions?

photosynthesis, transpiration, and gas exchange

Stomata

porelike openings in the underside of the leaf that allow carbon dioxide and oxygen to diffuse into and out of the leaf

Meristematic Tissue

produces cells that are undifferentiated (they have not yet become specialized). Only plant tissue that produces new cells by MITOSIS

What are trace elements and what do they include?

required in small quantitites for plant growth: sulfur, iron, zinc, molybdenum, boron, copper, magnese, and chlorine

Wilting

results from loss of water and loss of pressure in the plants cells. Stomatas close and transpiration slows down

Trichomes

some epidermal cells have tiny projections, help to protect the leaf and also give it a fuzzy appearance

Transpiration

the loss of water through its leaves

Gaurd cells

the specialized cells in the epidermis that control the opening and closing of stomata by responding to changes in water pressure. epidermal cells found on the underside of leaves

Capillary Action

the tendency of water to rise in a thin tube. Water is attracted to the walls of the tube, and water molecules are attracted to one another.

What is the purpose of roots

to anchor a plant in the ground and absorb water and dissolved nutrients from the soil

The role of phloem in bark

transports sugars produced by photosynthesis

Nodes

where the leaves attatch to the stems