Plant Biology Ch 4, 6, 7

cellulose

A carbohydrate that forms the structural component of plant cell walls

cell wall

A rigid layer surrounding plant cells, providing structure and protection

chloroplasts

Organelles where photosynthesis occurs.

chromoplasts

Plastids that store pigments responsible for colors in fruits and flowers.

cytoskeleton

a network of protein filaments providing structure and aiding in cell movement

amyloplasts

plastids that store starch

leucoplasts

colorless plastids involved in storage and biosynthesis

protoplasm

the living content of a cell, including cytoplasm and nucleus

cytoplasm

gel-like substance within the cell membrane excluding the nucleus

cytosol

the fluid portion of the cytoplasm

dictysome

another term for golgi apparatus in plant cells

endoplasmic reticulum (smooth and rough)

membrane-bound organelle involved in protein and lipid synthesis: rough ER has ribosomes, smooth ER does not

golgi apparatus

organelle involved in modifying, sorting, and packaging proteins and lipids

microbodies

small organelles involved in various metabolic processes

microfilaments

thin protein filaments in the cytoskeleton

microtubules

hollow protein tubes in the cytoskeleton

middle lamella

a pectin-rich layer between plant cell walls that cements cells together to form

mitochondria

organelles where cellular respiration occurs, producing energy

nucleolus

a structure within the nucleus where ribosomes are assembled

nucleus

control center of the cell containing genetic material

organelles

specialized structures within a cell performing specific functions

plasmodesmata

channels between plant cells for communication and transport

plastids

organelles involved in storage and synthesis of compounds

primary pit field

thin areas in the cell wall with plasmodesmata

ribosomes

structures where protein synthesis occurs

central vacuole

a large vacuole in plant cells for storage and maintaining turgor pressure

tonoplast

the membrane surrounding the central vacuole

nucleoplasm

the substance within the nucleus

microfibril

a component of the cell wall made of cellulose

hemicellulose

a polysaccharide in the cell wall that provides support

pectins

polysaccharide in the cell wall that acts like glue to bind adjacent cells together

lignin

a complex polymer providing rigidity to the cell wall

primary cell wall

the first-formed flexible cell wall layer

secondary cell wall

a thicker rigid cell wall layer formed inside the primary wall

benefit of unicellular organization

Simplicity in structure, rapid reproduction, and adaptability to changing environments

negative consequences of unicellular organization

Limited functionality and inability to perform specialized tasks

benefit of multicellular organization

Specialization of cells for specific functions, greater complexity, and ability to form tissues and organs

negative consequence of multicellular organization

Higher energy requirements and dependence on coordinated functioning of all cells.

plasmodesmata’s method of communication

microscopic channels that traverse the cell walls of plant cells, allowing direct communication and transport of substances (e.g., ions, nutrients, signaling molecules) between adjacent cells. They enable coordination and integration of cellular activities across the plant.

what are the components of plant cell walls

cellulose, hemicellulose, pectins, lignin, primary cell wall, secondary cell wall

angiosperm

flowering plants that produce seeds enclosed in fruit

axillar bud

bud located at the junction of a leaf and stem

bulbs

underground storage organs made of modified leaves

apical meristem

a region of actively dividing cells at the tips of roots and shoots

basal angiosperms

primitive flowering plants

circular bordered pits

structures in xylem cells for water transport

collenchyma cells

elongated cells with unevenly thickened walls that provide flexible support to growing parts of the plan

perforation

openings in vessel elements for water flow

companion cells

cells associated with sieve tube elements in phloem

corms

short vertical swollen underground stems

cortex

outer layer of tissue in stems and roots

cuticle

waxy layer on epidermis preventing water loss

cutin

waxy substance in the cuticle

distichious

leaves arranged in two vertical rows

decussate

opposite leaves arranged at right angles

epidermis

the outermost layer of cells in plants

eudicots

a major group of angiosperms with two seed leaves

fibers

long slender cells providing support

ground meristem

meristem producing ground tissue

guard cells

cells controlling the opening ofnstomata

internodes

stem segments between nodes

metaphloem

mature phloem tissue

metaxylem

mature xylem tissue

monocots

angiosperms with one seed leaf

nodes

parenchyma fr

Thin-walled, living cells involved in photosynthesis, storage, and secretion. They are the most common and versatile plant cells.

phloem

vascular tissue transporting sugars

phylotaxy

the arrangement of leaves on a stem

pits

thin areas in the cell wall for transport

pit membrane

the layer between pits in adjacent cells

pit-pair

two pits in adjacent cells

pith

central tissue in stems and roots

primary growth

growth in length from apical meristems

primary tissues

tissue formed during primary growth

protoderm

outermost layer of the apical meristem

protophloem

the first formed phloem

protoxylem

the first formed xylem

provascular tissues

tissues that develop into vascular tissues

rhizomes

horizontal underground stems

sclerids

short thick walled sclerenchyma cells

sclerenchyma

Thick-walled, dead cells that provide structural support. They include fibers and sclereids.

sieve areas

regions in the walls of sieve elements containing clusters of pores for transport between cells

sieve cells

sieve plates

sieve pores

openings in sieve plates that allow the movement of substances between sieve tube members in phloem

sieve tube

a series of connected sieve tube members that transport sugars and other nutrients in the phloem

sieve tube members

specialized phloem cells that form sieve tubes and are involved in nutrient transport

sieve element

a conducting cell in the phloem including sieve tube members and sieve cells

spiral

a helical arrangement of secondary cell wall thickenings in xylem elements aiding in water transport

stomata

pores in the epidermis of leaves and stems that allow gas exchange (CO2, O2 and water vapor) between the plant and the environment

tracheary element

water conducing cells in the xylem including tracheids and vessel elements

tracheids

long narrow xylem cells with tapered ends that transport water and provide structural support for

trichomes

hair like structures on the surface of plant epidermis that can reduce water loss, protect against herbivores, or aid in secretion

tubers

swollen underground stems that store nutrients such as potatoes

vascular bundles

strands of vascular tissue (xylem and phloem) that transport water, nutrients and sugars throughout the plant

vessel

a water-conducting structure in xylem composed of vessel elements

vessel elements

short wide xylem cells with perforations that allow efficient water transport

xylem

vascular tissue responsible for transporting water and dissolved minerals from roots to other parts of the plant

whorled

a leaf arrangement where three or more leaves grow at a single node in a circular pattern

opposite

a leaf arrangement where two leaves grow directly opposite each other at the same node