Lecture 11: Plant Structure Flashcards
What are the key features/functions (4) of a plant?
- gain energy through photosynthesis
- nutrients are absorbed through roots
- grow indeterminately
- stationary
Define: angiosperm vs gymnosperm
- angiosperm: flowering plants
- gymnosperm: coniferous trees
What is meant by phenotype plasticity?
the ability of one genotype to produce more than one phenotype when exposed to different environments
What is the general function of roots(2)?
- nutrient uptake and plant anchoring
Besides the main 2 general functions of plant roots, what are 3 other specialised functions of some plant species?
- storage (carrots and beats)
- anchoring (ivy)
- adventitious roots (roots that arise from non root tissue in response to stress conditions)
What is meant by morphologic diversity?
- evolutionary adaptations to the environment
There’s a wide diversity of leaves. Why?
Maximize SA while surviving environment (H2O dissapation) lead to evolutionary changes
List the 6 modified stems we discussed in class.
- cactus
- thorns
- tubers
- floral mimics
- traps
- bulbs
Explain the modified stem: cactus
- enlarged stem for water storage
- photosynthetic tissue on stem
- modified leaves to protect against herbivores (spiky)
Explain the modified stem: thorns
- modified stem tissue to protect against herbivores
Explain the modified stem: tubers
- stems grow underground and store carbs (starch like potatoes)
- nodes in stems give rise to new branches
Explain the modified stem: floral mimics
- attract pollinators
Explain the modified stem: traps
- trap insects
Explain the modified stem: bulbs
- thickened leaves store nutrients
Identify the structures with the red squares in the plant cell drawing
- see google doc
define: plasmodesmata
- gaps that connect adjacent cells
What are the 4 distinguishing structures in a plant cell that don’t exist in animals
- cell wall
- vacuole
- chloroplast
- plasmodesmata
List the 3 plant tissue systems
- dermal
- ground
- vascular
Explain the plant tssue system: dermal tissue
- aka
- function
- examples (3)
- AKA epidermis
- function: protect cell from water loss, disease, etc
- cuticle, stomata, trichomes
Explain the plant tissue system: ground tissue
- what are the 3 types
- parenchyma
- collenchyma
- sclerenchyma
Explain the plant tissue system: vascular tissue
- what are the 2 types; explain their functions
- xylem: transport H2O and dissolved nutrients from root to shoot
- phloem: transport sugars, amino acids, etc in both directions (root to shoot, shoot to root)
define: trichomes
- hair-like structures; physical deterrance against insects
Explain this type of ground tissue: parenchyma
- workhorse cells: involved in photosynthesis and storage; totipotent (can form a new plant)
Explain this type of ground tissue: collenchyma
- flexible, structural support
Explain this type of ground tissue: sclerenchyma
- structural support fibres: often dead tissue
- form the thick secondary wall made of lignin
Explain: meristems
- undifferentiated cells that can differentiate into distinct cells with specific properties
Define: apical meristems (location and function)
- located at the tip of root and shoots
- responsible for primary growth
What are 3 types of primary meristems
- ground meristem: ground tissue
- protoderm: dermal tissue
- procambium: vascular tissue
In a root, there are 3 zones. Can you state them and what falls under each zone?
- see google doc
What is the purpose of primary growth (2)?
- increases length of root and shoot
- increases absorption of light and nutrients
If shown a cross section of a root or shoot, can you identify the 3 types of tissue systems?
- see google doc
What is the purpose of secondary growth?
- increases width of roots and shoots
- only in plants with cambium (special type of meristem; aka lateral meristem)
define cambium
- special type of meristem (lateral meristem)
- forms cylinder around root, branch, or tree trunk
- cells grow laterally
Do you understand the secondary plant growth that is shown on the pie wedge on the google doc?
- see google doc
