Plant Development Flashcards
Vascular plants have 2 distinct organ systems
shoot system: stems and leaves and reproductive parts of the plant; above ground; light for photosynthesis
root system: plants absorts water water and minerals; underground
organs and tissues in plants
roots, stems and leaves; each include 3 tissues types (ground, vascular, dermal)
3 major functions of root system of seed plants
- anchoring plant to soil
- absorbing water/minerals and transporting them upwards
- storing products of photosynthesis - some can absorb moisture and exchange gases - usually underground
2 types of root systems
tap root systems: main root that grows down vertically, smaller lateral roots, deep into soil, good for dry soil plants, usually with dicots like dandelions
fibrous root systems: closer to surface, dense network, prevents soil erosion, usually monocots like grasses
root structures with evolutionary adaptions of specific purposes
bulbous roots - store starch
aerial roots and prop roots: above-ground that support additional anchoring
tap roots: some are for sugar and starch storage like carrots, turnips, beets
epiphytic roots: plants to grow on another plant
main function of stems (3-4)
- support to plant, holding leaves, flowers, buds
- connect roots to leaves
- transporting absorbed water and minerals from roots to rest of plant
- transporting sugars from leaves to desired locations throughout plant
4 types of stems
herbaceous - soft and greem
woody - hard and wooded
unbranches - single stem
branched - divisions and side stems
typical structures
nodes (point of attachment for leaves and flowers) and internodes (regions in between nodes)
tip of the shoot: apical meristem within the apical bud
auxilary bud: found in the area between the base of a leaf and stem where it can give rise to a branch of flower
reproductive shoot
flower
leaves
main site of photosynthesis - making food
green because of chlorophyll! but some leaves can have different colors with other plant pigments
petiole and veins
petiole: what attaches leaves to the plant stem
veins: vascular tissues like zylen and phloem through the leaves; also provide structural support
leaves changes to adapt to specific environments
coniferousplants of cold environments: smaller, needle leaves - small surface area and sunken stomata (gas exchange) for less water loss
– ex. cacti with spines and succulent stems
aquatic plants: leaves with wide lamina to float and thicker cuticle to repel water
2 types of plant tissue systems
meristematic tissue: undifferentiated like animal stem cells - continue to divide and growth of plant
permanent(non-meristematic): no longer actively dividing, meristems produce cells that quickly differentiate and become permanent tissues
3 main tissue types
dermal, vascular, ground
dermal tissue
protects the plant, gas exchange, water absorption; waxy cuticle to prevent evaporative water loss, stomatas for gas exchange, root epidermis don’t have waxy cuticle
root hairs - extension of root epidermal cells to increase surface area of roots and more absorption
trichomes - spiky outgrowths of epidermal tissue on stem and leaves which aid in defense against herbivores
types of cells: epidermal cells, guard cells - stomata, trichomes
ground tissue
different functions based on cell type and location
parenchyma - photosynthesis and storage in roots
collenchyma - shoot support of active growth
sclerenchyma - shoot support in areas of inactive areas
supportive matrix for vascular tissue, structural support, storage of water and sugars
vascular tissue
transport of water and nutrientss
xylem - water and nutrients from roots to different parts of plants plus structural support
phloem - food, organic compounds to other parts of plants
vascular bundle: xylem and phloem are adjacent to each other
cells: tracheids, vessel elements, sieve tube cells, companion cells
what all plants cells share
primary cell walls which are flexible and can expand as cell grows and elongates
some have secondary cell wall of lignin (wood) and inflexible for support