Chapter 35 Flashcards
Organs of a plant
root, stem, leaves
roots
multicellular organs
anchors plant
absorbs minerals and water
store organic nutrients
Tissues of plants
Dermal
vascular
ground
Dermal tissues
epidermis
peridermis
epidermis
make-up non woody plants
periderm
protective tissue ion woody plants
replaces the epidermis in older regions
vascular tissue
xylem
phloem
xylem
conveys water
dissolves minerals upward from roots and shoots
phloem
transport organic nutrients from where they are made to where they are needed
ground tissues
include cells specialized from storage, photosynthesis and support
pith
cortex
pith
internal to vascular tissue in the stem
cortex
external to vascular tissue
Parenchyma
perform the most metabolic functions
retain the ability to divide and differentiate
collenchyma
helps support young parts of the plant and shoot
provides flexible support without restraining growth
Sclerenchyma
dead at functional maturity
rigid due to thick secondary walls strengthened with lignin
sugar-conducting cells of the phloem
sieve-tube elements are alive at functional maturity
lack organelles
Meristem
tissue in plants consisting of undifferentiated cells
embryonic tissue
allows for indeterminate growth
gives rise to initials and derivatives
indeterminate growth
growth throughout a plants life
Initials
remains in the meristem
derivatives
become specialized in developing tissues
determinate growth
when plant organs cease to grow at a certain size
apical meristem
elongate shoots and roots through primary growth
primary growth
apical meristems elongate shoots and roots
lateral meristems
add thickness to woody plants through secondary growth
2 types: vascular cambium, cork cambium
vascular cambium
adds layers of vascular tissue
cork cambium
replaces the epidermis with periderm
three development processes of plants
growth
morphogenesis
cellular differentiation
Growth in plants
consists of cell division and cell expansion
cell division: increases the potential for growth
cell expansion
accounts for the actual increase in plant size
cells grow rapidly and “cheaply” by in taking and storing water in the vacuole
Morphogenesis
the development of body form and organization and is often controlled by homeotic genes
Pattern Formation
the development of specific structures in specific locations
positional information
determines pattern formation in the form of signals indicating to each cell its location
polarity (pattern formation)
having structural or chemical differences at opposite ends of an organism
provides one type of positional information
cellular differentiation
cells of a developing organism synthesizes different proteins and diverges into structure and function even though they have the same genome
depends on positional information and is affected by homeotic genes
phases changes
developmental phases
from juvenile phase to adult phase
vegetative growth
involved in flower formation
triggered by a combination of environmental cues and internal signals
meristem identity gene
causes the transition from vegetative growth to flowering
organ identity gene
plant homeotic genes
regulates the development of floral patterns
mutation in the organ identity gene can?
cause abnormal floral development
