plants - lecture 1 Flashcards
What are plant microbodies?
- peroxisomes
- Glyoxysomes
What is the function of peroxisomes
ROS release for plant immunity
What is the function of Glyoxysomes
Acetyl CoA production from fatty acids
Why is it necessary for bacteria and plants to have strong cell walls?
Bacteria: crucial protection from a hostile environmnent.
Plants: crucial support as sessile organisms.
How do bacteria operate?
Operate in large colonies creating biofilms
What is a metzoan?
A multicellular organism
What are the 3 types of vegetative parts of a plant (non - flowering parts)?
- roots
- Stems
- Leaves
Function of the root system
take up of water, minerals e.g. nitrates (transpiration, capillary action, apoplastic and symplastic movement, osmotic pressure) UPWARDS
Function of the stems system
support vascular transport BOTH WAYS, prevent lodging
Functions of the leaves system
Photosynthesis, making of sugars and proteins
DOWNWARDS
What are the 5 plant kingdoms?
- algae
- Bryophytes
- Pteridophytes
- Gymnosperm
- Angiosperm
What do angiosperms have?
- fully enclose seeds which are flowering
How are the angiosperms divided into groups?
- Monocots
- Dicots
What are the qualities of monocots
- one cotyledon
- veins are usually parallel
- Vascular bundles usually complexly arrange
- Fibrous root system
- floral parts usually in multiples of 3
what are the qualities of dicots?
- two cotyledons
- Veins usually netlike
- vascular bundles arranged in a ring
- taproot usually present
- floral parts usually in multiples of 4s or 5s
What are the 3 functions of a root?
- Anchoring the plant
- Absorbing water and minerals (e.g nitrates)
- Storing carbohydrates (sucrose into starch)
What is the primary root?
- first root emerging from a germinating seed
Which plant types have a taproot system?
- most gymnosperms(pines) and eudicot angiosperms
What is a taproot system?
- A taproot, the main vertical root
- Lateral roots, or branch roots, that arise from the taproot
What type of root systems do monocots have?
- fibrous root system
What is a fibrous root system?
- Adventitious roots that arise from stems or leaves
- Lateral roots that arise from the adventitious roots
What are prop roots?
- supporting top heavy trees
What are examples of prop roots?
- Hala trees that grow in sandy soils in the South Pacific
What are Buttress roots
Aerial roots that support the tree
What are examples of buttress roots?
In tropical forests root systems of trees can be very shallow due to competition for resources.
What are strangling aerial roots?
germinate in the branches of tall trees, send aerial roots to the soil.
Eventually the “host” tree dies through shading
What are pneumatophores?
negatively geotropic roots to obtain oxygen which is
lacking in thick estuarine mud
What are the nodes and internodes in a stem?
nodes - the points at which leaves are attached
internodes - the stem segments between nodes
What is an axillary bud?
bud has the potential to form a lateral shoot, or branch, tip of the plant
What is an apical bud?
causes elongation of a young shoot, or part of it can differentiate to give rise to a reproductive organ
What is an rhizome?
Horizontal shoots that grow just below the the soil surface
What are stolons?
horizontal shoots that grow along the soil surface and allow asexual reproduction of plantlets at nodules along the stolon
What are tubers?
Tubers are enlarged ends of rhizomes or stolons for storing food
What are bulbs?
Bulbs such as this onion are vertical underground shoots that store food
What do leaves generally consist of?
flattened blade and a stalk called the petiole, which joins the leaf to a node of the stem
How do monocots and edicts differ In the arrangement of the veins?
Most monocots have parallel veins
Most eudicots have branching veins
What are the 3 types of leaf?
- simple
- compound
- doubly compound
What are tendrils?
Tendrils are modified leaves that plants such as this pea plant use to cling to objects.
Once attached the tendril coils pulling the plant closer to the support.
What are spines?
Spines are modified leaves and in this cactus.
What are reproductive lectures?
Reproductive leaves of some succulents such as this Kalanchoe form adventitious plantlets that fall off and take root in the soil
What are Bracts?
are modified leaves surrounding flowers. Some bracts are brightly colored and attract pollinators.
What type of tissue doe each plant organ contain
- Dermal
- Vascular
- ground tissues
What is dermal tissue?
A protective layer
What is vascular tissue?
continuous transport system arranged differently in each organ
What is ground tissue?
where most metabolic functions take place, macromolecules taken to other parts of the cell
What are the two dermal tissue systems?
- non woody
- woody
What forms the non woody parts dermal tissue?
Epidermis: single tissue
Cuticle (waxy coating): prevents water loss
Trichomes: diverse functions
What forms the woody parts of the dermal tissue?
Periderm: several tissues
Reinforced cell walls: lignin and suberin
Complex polyphenols
What tissues make up the vascular system?
- Xylem
- Phloem
What does the xylem do?
Upward transport of water and
dissolved minerals
Lignin-reinforced walls
What does the phloem do?
Transport of organic compounds
How are the vascular tissues arranged in roots in eudicts vs monocots?
- Very small in the eudicots compared to monocots
How are the vascular tissues arranged in stems in eudicots vs monocots?
eudicots- forms a ring of vascular bundles
monocots - stem with scattered vascular bundles
What is internal to the vascular tissue?
The pith
What is external to the vascular tissue?
cortex
What are the types of ground tissue?
Usually unspecialized cell types Often give rise to dermal and vascular tissues Groups of cells specialized for: Storage, photosynthesis, support
What are the 3 major types of ground tissues systems?
- Parenchyma
- Collenchyma
- Sclerenchyma
What is another function of ground tissue?
Ground tissue gives rise to other tissue systems:
- Water-conducting cells of the xylem
- Sugar-conducting cells of the phloem
