Plants Test
what is an apical meristem?
a group of undifferentiated cells that divide to produce increased length of stems and roots
what is a vessel element?
a kind of xylem cell that angiosperms have
what is the apical meristem of a root surrounded by?
a root cap that protects the root as it grows in the soil
what is the cortex?
a spongy layer of ground tissue
what is a tracheid?
a type of xylem cell that is a long, narrow cell with waterproof walls and is found in seed plants
what do plants require to grow, flower, and produce seeds
a variety of inorganic nutrients in addition to carbon dioxide and water
what do roots do?
absorb, anchor, protect, transport, and hold plants upright
what do the cell membranes of root hairs and other cells in the root epidermis contain?
active transport proteins
what types of structures does a mature root have?
an outside layer, the epidermis, and a central cylinder of vascular tissue with ground tissue in between
How are organs of plants linked together?
by systems and subsystems that run the length of the plant
what does the transport system of the stem do?
carries nutrients and must contain subsystems that can lift water from roots up to leaves and carry the products of photosynthesis from the leaves back down to roots
what is a familiar thing that is made up of collenchyma?
celery stalk walls
what is a parenchyma cell?
cells that function mainly in storage and photosynthesis
what are root hair cells in plants?
cells that provide a large amount of surface area and aid in water absorption
what is the vascular cylinder?
central region of a root that includes the vascular tissue
what are meristems?
clusters of tissues that are responsible for continuing growth throughout a plant's lifetime
what are the two types of ground cells with thicker cell walls?
collenchyma sclerenchyma
in what tissue are guard cells found?
dermal tissue
what tissue are root hairs found on?
dermal tissue
what types of tissues do vascular plants contain in each organ?
dermal, vascular, ground
where is the taproot mainly found?
dicots
what are the zones in a root?
division (apical meristem), elongation (after the apical meristem), maturation (after elongation)
how are vessel elements arranged?
end to end on top of one another like a stack of tin cans
how are sieve tube element cells arranged?
end to end to form sieve tubes
what does dermal tissue consist mostly of?
epidermal cells
what are some things that taproots do?
extend far to reach water and stay short to store sugars or starches
how tall can stems be?
few millimeters to 100 meters
what is an example of a fibrous root?
grass
what do root systems protect the plant from?
harmful soil bacteria and fungi
what does it mean to be undifferentiated?
have not yet become specialized for specific functions
where does most of the increase in root length occur?
immediately behind the meristem
where are the highly specialized cells (which make up the reproductive system of flowering plants) found in flowers produced?
in the meristems
where is the endodermis?
inside the cortex of a root
what type of growth do most plants have?
intermediate
what does the support system of the stem do?
is is a support system for the plant body by holding up its leaves and branches
why is it important that leaves have broad, flat surfaces?
it helps increase the amount of sunlight they absorb
what does the defense system of the stem do?
it protects the plant against predators and disease
how does the root cap protect the root?
it secretes a slippery substance that lubricates the progress of the root through the soil
where is the cortex?
just inside the epidermis of a root
what is the endodermis?
layer of cells that completely encloses vascular tissue
what are the plants main photosynthetic systems?
leaves
what is the only plant tissue the produces new cells by mitosis?
meristematic tissue
where are intermediate growth cells produced?
meristems
where is the fibrous root mainly found?
monocots
where is the apical meristem?
near the end or tip of each growing stem and root
what are both xylem and phloem made up of?
networks of hollow connected cells that carry fluids throughout the plant
what are the most important nutrients that a plant needs?
nitrogen, phosphorous, potassium, magnesium, calcium
what are examples of taproots?
oaks, hickory tree, carrots, dandelions, beets, radishes
what are the walls of tracheids pierced by
openings that connect neighboring cells to one another
in most plants, what does ground tissue consist mainly of?
parenchyma cells
what do root hairs do?
penetrate the spaces between soil particles and produce a large surface area through which water can enter the plant
what do the systems and subsystems in the plant do?
perform functions such as transport and protection and coordinating plant activities
what are companion cells?
phloem cells that surround sieve tube elements
what is the meristematic tissue?
plant tissue found only in the tips of shoots and roots, responsible for plant growth
what is intermediate growth?
plants grow and produce new cells at the tips of their roots and stems for as long as they live
what does the root's epidermal subsystem perform?
protection and absorption
what do guard cells on the underside of leaves do?
regulate water loss and gas exchange
What are the three principal organs of seed (vascular) plants?
roots, stems, leaves
what are the main phloem cells?
sieve tube elements
what does the phloem consist of?
sieve tube elements and companion cells
why do the walls of sieve tubes have holes in them?
so that materials can move through these holes from one adjacent cell to another
what type of cell walls do collenchyma have?
strong, flexible walls that help support larger plants
what do companion cells do?
support the phloem cells and aid in the movement of substances in and out of the phloem
what systems does a stem have?
support, transport, defense
what is the primary root?
taproot
what are the two main types of roots?
taproots and fibrous roots
what makes up the ground tissue?
the cells that lie between the dermal and vascular tissues
what is the thick waxy coating of the epidermal cell known as?
the cuticle
what do the actions of the genes that transform apical into floral meristems produce?
the modified leaves that become the flower's colorful petals, as well as the reproductive tissues of the flower
what happens as a result of the meristematic tissue that lines the stems and toots of a plant?
the plants also grow in width
what is differentiation?
the process in which cells become specialized in structure and function
what are trichomes in an epidermal cell?
the tiny projections which help protect the leaf and also give it a fuzzy appearance
how do roots grow in length?
their apical meristem produces new cells near the root tip
what is the structure of epidermal cells like?
their outer surfaces are often covered with a thick waxy layer that protects against water loss and injury
what happens to the cell walls of vessel elements when they die?
they are lost and transform the stack into a continuous tube through which water can move freely
what do the parenchyma cells do in leaves?
they are packed with chloroplasts and are the site of most of a plant's photosynthesis
what happens when tracheids mature?
they die and their cytoplasm disintegrates
what happens to vessel elements when they mature?
they die before they conduct water
how are the cells that originate in the meristems similar ar first?
they divide rapidly and have a thin cell wall
why must leaves contain subsystems that protect against water loss?
they expose a great deal of tissue to the dryness of the air
how do adjustable pores in leaves help
they help conserve water while letting oxygen and carbon dioxide exit and enter the leaf
what happens to the remaining organelles in the sieve tube cell after it matures?
they hug the inside of the cell wall and the rest of the space is a pipeline through which sugars and other foods are carried in a watery stream
what happens to sieve tube elements as they mature?
they lose their nuclei and most of the other organelles in their cytoplasm
what happens as the cells produced in the meristem differentiate?
they produce each of the tissue systems of the plant
what type of cell walls do sclerenchyma have?
thick, rigid walls that make ground tissue tough and strong
what is the structure of a parenchyma cell?
thin cell walls and large central vacuoles surrounded by a thin layer of cytoplasm
what are root hairs?
tiny cellular projections that cover the surface of a root
why do roots anchor?
to keep the plants in the soil and prevent erosion
what do the fibrous root systems produced by many plants help prevent?
topsoil from being washed away by heavy rain
what does the xylem consist of?
tracheids and vessel elements
what are the new cells produced in the meristematic tissue like?
undifferentiated
what is wider: tracheid or vessel element?
vessel element
What do roots absorb?
water and dissolved nutrients
what do plants transport?
water and nutrients to the rest of the plant
when does flower development begin?
when certain geners are turned on in a shoot apical meristem and transform the apical meristem into a floral meristem
what are the principal subsystems in vascular tusse?
xylem and phloem
do companion cells keep their nuclei and other organelles through their lifetime?
yes
does it take energy for a root to soak in water?
yes
do all seed plants have a tracheid?
yes, SEED plants
