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