exam 1 Flashcards
protoplasm
organelles, lipids, proteins, and nucleic acids within the cell - no cell wall
primary cell wall
parallel cellulose microfibrils which cover plasma membrane, bound together by hemicellulose, walls are glued together by the middle lamella composed of pectin
secondary cell wall
like seed coats, tracheids xylem cells, between primary and plasma membrane
ribosomes
found in protein-rich seeds as well as plants with digestive enzymes
central vacuole
tonoplast membrane - stores water and salts, able to digest old organelles and recycle nutrients
mitochondria
cellular respiration
plastids
young type - 5 types, chloroplasts, amyloplasts, leucoplasts, chromoplasts, etioplasts
etioplast
occurs when tissues are grown without light - stage in the transformation of protoplastids to chloroplasts
leucoplasts
colorless - occurs in plants without light or underground - roots and seeds - lead to amyloplasts
amyloplasts
starch storage in nonphotosynthetic areas of plant
chromoplasts
store bright lipid pigments
dictyosomes
like the Golgi, but for plants
microbodies
spherical bodies that produce or use hydrogen peroxide - peroxisomes detoxify biproducts
glyoxisomes convert stored fats into sugar
plasmodesmata
a small stream of the ER and cytosol that passes through the plasma membrane of adjacent cells - occur in clusters called primary pit fields
what are the basic cell types in plants
parenchyma, collenchyma, schlerenchyma
parenchyma
thin primary cell walls, metabolically active, alive at functional maturity - make up phloem
what are the 4 kinds of special parenchyma
glandular, phloem, chlorenchyma, transfer cells
what are the benefits of parenchyma
inexpensive to build, most leaves are soft and made up entirely of parenchyma
collenchyma
unevenly thickened primary cell walls, allows for plasticity, occurs beneath the epidermis and supporting vascular bundles
what are the types of collenchyma
angular, annular, lamellar, lacunar
schlerenchyma
thick secondary cell wall, elastic strength, supoort the plant, dead at functional maturity
what are the two types of schlerenchyma
mechanical - long flexible fibers - brittle sclereids
conductive
what is conductive sclerenchyma
small plasmodesmata-rich area, two make up a pit pair, transports water, makes up tracheids and vessel elements in xylem
what are the three types of plant tissues
dermal tissue, ground tissue, and vascular tissue
what are the 5 types of dermal tissues
cuticle, guard cells, stomata, root hairs, trichomes
epidermis
single outer layer of parenchyma cells, protection, prevent H2O loss
cuticle
cutin - outer tangental walls coated, waterproof, not as rewarding to eat
guard cells and stomata
allow for gas exchange, stomatal pore surrounded by guard cells - help to regulate what comes in and out
how to guard cells work
swell by absorbing water - closed at night or during period of water stress
trichomes
epidermal cells that extend outwards - deter herbivory, minimize water loss, protect from sunlight, can act as secretory glands
root hairs
extension of root epidermal cells - help absorb more
what are the types of ground tissue
cortex and pith (eudicots)
cortex
interior to epidermis - homologous, composed mostly of photosynthetic parenchyma and some collenchyma
aerenchyma
cortex that is loosely packed with large cellular spaces
pith
interior to vascular bundles in ground tissue - soft spongy parenchyma - sometimes stores starch
vascular tissues
conducts materials throughout the plant - xylem (dead) and phloem (alive)
xylem
tracheid and vessel elements - all made up of sclerenchyma - dead at functional maturity - pit membranes
vessel elements
angiosperms - long-distance water and nutrient travel
phloem
sieve cells and sieve-tube members - parenchyma cells and plasmodesmata for sieve pores
sieve tubes
sieve plates - only in angiosperms
albuminous cell
nonflowering plants, control the phloem
companion cell
flowering plants - control the phloem - prominent nucleus and dense cytoplasm - complex network of passages
leaf axil
stem area right above where the leaf attaches - axillary bud, apical meristem, several young leaves
terminal bud
extreme end of a stem
phyllotaxy
positioning of leaves on a stem
what are the three major phyllotaxy
alternate - one each node
opposite - two each node
whorled - three or more
what are the external organization of stems
distichous - two rows from above
decussate - 4 rows from above
spiral - like a spiral staircase
what are the stem modifications
stolons - fall over and keep growing
tubers - like potatoes
bulbs - thick fleshy leaves
rhizomes - fleshy horizontal stems
