Chapter 23 Flashcards
What did plant ancestors look like
single celled, aquatic. like green algae
terrestrial life means
greater complexity and specialization
roots
uptake for water, minerals
shoots
places for photosynthesis, reproduction
special feature of plants
dynamic architecture: continually grow throughout their lives
angiosperms
flowering plants
-most complex and most recently evolved
monocots
one cotelydon, veins parallel, vascular bundles complex arrangement, fibrous roots, flowers in multiples of 3
eudicots
2 cotelydons, veins net like, vascular bundles in ring, taproot is present, flowers in multiples of 4 or 5
plant systems
root, shoot
plant organs
root, stem, leaf
2 stages of plants
vegitative: stems, leaves, no flowers
reproductive: flowers and fruits, as well as stems and leaves
root function
anchorage, absorbtion of water and minerals, storage
root forms
tap root, fibrous root, adventitious (roots from stem, not embryo)
shoot parts
stem, leaf, bud
bud
source of new growth in shoot, forms branches or flowers
terminal bud
tip of stems
axillary bud
in axils of leaves
stem function
support, transport, storage
-usually elongated, cylindrical, and vertical
rhizome root
long and horizontal
bulb root
short and horizontal
runner
vertical and flat
tuber root
varying positions around plant
types of roots
rhizome, bulb, tuber, runner, tap root, fibrous root
leaves function
photosynthesis
leaves morphology
broad and flattened for efficient gas uptake and light absorbtion
all organs have what 2 tissues
epidermis and vascular tissue
dermal tissue system
outer covering of plant
ground tissue system
carries out photosynthetic products, helps support plants
vascular tissue system
conducts water and solutes throughout the plants
bryophytes
simplest land plants. single layer thickness of photosynthetic structures. water conducting cells are not vascular, lack wall structure
plant cell contents
nucleus, mitochondria, ribosomes, golgi apparatus, endoplasmic reticulum (all in cytoplasm of plant and animal cells) cytoplasm and plasma membrane
special plant cell features
chloroplasts, vacuoles, cell walls, plasmodesmata
plasmodesmata
share small molecules between cells
primary cell wall
all new cell walls
secondary cell wall
added later, internal to primary wall, reinforce
plant cell types
parenchyma, sclerenchyma, transport
parenchyma
living cells, primary cell wall, metabolic processes
sclerenchyma
thick secondary walls strengthen with lignin, support and rigidity, dead cells, long slender (fibers)
transport cells tissue types
xylem and phloem
phloem tissue contains
sieve elements (elongated with holes)
xylem tissue contains
tracheids, vessel elements. tracheids are hollow dead tubes, no cytoplasm: contents break down as cell differentiates. all vascular plants have tracheids, angiosperms only have vessel elements
xylem
conducts water
phloem
conducts food
vessel elements
elaborate secondary walls, in angiosperms only
sieve elements contents
alive but lack nucleus, ribosomes, mitochondria, vacuole
every sieve element has
companion cells: provide metabolic functions for neighbors. retain nucleus, mitochondria, and has plasmodesmata
meristem
growing points, at tips of roots and shoots. cells are not differentiated and can still divide unlike a mature leaf
three types: root meristem, shoot meristem, vascular cambium
root anatomy
outside to inside: epidermis, cortex, vascular tissue stele, xylem and phloem
gymnosperms and eudicots stele arangement
ring formation
monocot stele formation
scattered- cannot form rings
leaf layers top to bottom
upper epidermis, spongy mesophyll, vascular bundles, palisade mesophyll, lower epidermis, stoma
secondary growth increases the
diameter, adds phloem and xylem to existent cambium
vascular cambium is
the third kind of meristem
-meristem is just cells that can undergo cell division before they become specialized. remember cells go: division- elongation- maturation in root
precambium turns into
vascular cambium
annual rings
as water level increases then decreases through the seasons, cells vary in size–> cause rings
