Chapter 34 Flashcards
Why the plant body is dynamic
Indeterminate growth
Indeterminate growth
plant growth in which the main stem continues to elongate indefinitely without being limited by a terminal inflorescence or other reproductive structure.
Functions of plant
Gains inorganic resources like sunlight, CO2, H20 \
Use photosynthesis to make organic molecules
Root system functions
Anchor plant to soil
Take up ions and water from soil
Conduct water and ions to shoot system
Obtain energy from sugar in the shoots
Store molecules produced by shoots
Where does a majority of photosynthesis occur in plants
Leaves due to a large surface area available for absorbing photons
Bulbs
Onion bulb store nutrients
Floral mimics
Modified to have different colors and attract pollinators
Succulent leaves
Succulent leaves store water
Traps
Modified leaf that traps insects for food
Tendrils
Allow vines to climb
Three tissue systems found in plants
Dermal tissue system
Ground tissue system
Vascular tissue system
What are features plant cells have not found in animals
- Surrounded by cellulose-rich primary cell wall and a rigid secondary cell wall
- Plant cells are interconnected by plasmodesmata
Dermal Tissue System
Consists of dermal tissue (skin tissue) also called epidermis (outermost layer of cells of any multicellular organism)
- Epidermal cells secrete cuticle
- Stomata
- Trichomes
Cuticle
Hydrophobic, waxy layer that covers shoots, protecting leaves and reducing water loss
Stomata
Part of dermal tissue system
regulate exchange of gases
– Open when plenty of water, allows CO2 to enter
– Close when H2O scarce, preventing excess water losss
Surrounded by two specialized guard cells, change shape to open or close the pore
Trichomes
Part of Dermal Tissue system
Hair-like appendages
- Keep plant cool and protect against damaging sunlight
- Minimize water loss
- Regulate gas exchange in shoots
- Provide barbs or toxins to protect from herbivores
Ground tissue system and types
Most photosynthesis and carbohydrate storage take place in ground tissue
Cells in ground tissue are responsible for most of the synthesis and storage of specialized products required for defense
Three cell types:
Parenchyma
Collenchyma
Sclerenchyma
Parenchyma
Type of cell in the ground tissue system
- Most abundant and versatile plant cells
- Primary site of photosynthesis in leaves
3.Mainly store starch in roots
These cells are totipotent
Alive at maturity and have functioning nuclei
Totipotent
Continue to divide and develop into a mature cell
Helps in repair of wounds and reproduction
New plants can grow from cuttings
Collenchyma
Type of totipotent cell in the ground tissue system
Have primary cell walls that continue to expand and provide flexible support to growing regions of shoots
Support growth: Found in elongating stems and leaf petioles, just underneath the epidermis