Ch 32-34 Plant Biology Flashcards
What three tissue types make up a plant ? And which are alive or dead
- Parenchyma (alive)
- Collenchyma (alive)
- Sclernchyma (dead)
Parenchyma Tissue
- contains mesophyll cells (photosynthetic)
- are alive at maturity
- repairs plant wounds (cellular division)
Collenchyma
- elongated and alive at maturity
- supports young plants that grow rapidly because they are flexible
Sclerenchyma
- dead at maturity
- gives support to plants by using lighin and resist compression
- water resistant
- sclerids strengthen hard seed coats (peach pits)
What type of cells does the vascular tissue contain?
Tracheid cells
What does the xylem do? Is energy needed to transport water? How does it work? What theory is used to describe transport of water? How does it work
- xylem transports water
- does not use energy
- cohesion tension theory
1. water tension: water molecules hang on to each other, as one exits the other pulls it up like a conveyer belt
2. Water moves from an area of high water potential/concentration to low
What does the phloem do? What cells are found within the phloem? Is energy needed to transport sugars? What theory and model is used to describe how sugars are transported? How do they work?
-transports sugars and other nutrients
-companion cells alive at maturity, they load sugar into sieve tubes
-pressure flow theory: uses energy it is active transport
1. Companion cells transport sugars against concentration gradient into sieve tubes
2. Inside sieve tubes: increase in solute concentration that lowers water concentration inside
Water moves by osmosis
3. It increases water volume and pressure in sieve tube
4. The increase in pressure causes sugar fluid to flow toward sink areas
5. Sugars unload into sinks: high water concentration in tubes water goes out phloem by osmosis
-source to sink model
Source to sink model
-source: high sugar concentration, photosynthesis produces sugars and companion cells load sugar into sieve tubes
-sink: low sugar concentration, sugar goes where it is needed/ stored (roots/fruits)
SOLUTES MOVE DOWN THEIR CONCENTRATION GRADIENT FROM HIGH TO LOW
What does dermal tissue have?
Epidermal cells that contain a waxy cuticle
What does stomata do? What does it balance? Where are they found?
- allows for gas exchange
- controls/balances CO2 intake and water loss
- open: get CO2 but loses water
- closed: conserves water but can’t get O2
- underside of leaf
Monocot vs dicot
Look at other flash cards
What is primary growth? Do all plants show this? What areas show growth? What are meristems?
- plants grow root to tip
- no only vascular
- meristems are where cells continuously divide rapidly
- apical meristems vertical growth shoot to tip
- old tissue at bottom young at the top
- grows from nodes
What are the root systems?
- taproot: primary root; some branching, sturdy, strong support, reach water in deep soil, dicots
- fibrous: lots of branching, compete for water, shallow, reaches large areas, not a lot of support, monocots
What are some taproot adaptations? How do they help the plant?
- root hairs: increased surface area for absorbing water and nutrients
- mycorrhizae: symbiotic relationship between roots and fungus. Hyphae gives it a large surface area an increases mineral and water absorption
- nitrogen fixation and root nodules: bacteria infects roots plants get fixed nitrogen since plants lack the enzyme to break down nitrogen but the bacteria has it
What is secondary growth? How is it different from primary growth? Do all plants show secondary growth?
- roots and shoots have woody growth
- lateral meristems secondary xylem
