Plant Structure, Growth, and Development Flashcards
What are some basic characteristics of ALL plants?
- multicellular
- photosynthetic
- adapted to land existence (vertical growth, protection from desiccation)
- share a common ancestor with green algae (charophytes) THINK CHARA
What are the two major groups of angiosperms?
monocot and eudicots
What are some characteristics of a monocot in regards to embryos, leaf venation, stems, roots, pollen and flowers?
one cotyledon
parallel veins
Scattered vascular tissue
fibrous root system (no main root)
pollen grain w/ one opening
floral organs in multiples of three
What are some characteristics of a eudicot in regards to embryos, leaf venation, stems, roots, pollen and flowers?
two cotyledons
net-like veins
vascular tissue arranged in rings
taproot (main root) usually present
pollen grain w/ three openings
floral organs in multiples of four or five
What are the three basic plant organs?
roots, stems, and leaves
What is the basic morphology of vascular plants?
organisms that draw nutrients froms the ground and above the ground.
What are the two systems that the roots, stems, and leaves are divided into?
Shoot system - leaves and stem
Root system - root
What are the functions of roots?
anchor plant
absorb minerals and water from soil
stores carbs and other reserves
What is the first root to emerge?
the primary root
What branches from the primary root? What do these do?
lateral roots
these improve anchorage and improve water absorption
What is the difference in the root system that a tall plant would have versus a smaller plant?
Tall: have a TAPROOT system that has a large taproot that prevents the plant from toppling and lateral roots that stem from it that are responsible for absorption
Short: have a FIBROUS root system which consists of adventitious roots that arise from stems or leaves, lateral roots arise from these adventitious roots
Where does most of the absorption occur in roots?
Near the tips of the roots, called the root hairs.
These help to increase the surface area of roots.
What are some specializations of roots (5)?
Prop roots - support tall, heavy plants (corn)
Storage roots - (beets)
Pneumatophores - gas exchange for plants that grow in water (mangroves)
aerial roots - climbing, capture moisture in the air or perform photosynthesis, wrap around host in some cases, killing it.
buttress roots - for plants w/ shallow root systems to help w/ support
What is a stem made up of?
This is an alternating system of nodes and internodes.
Nodes are where leaves attach and internodes are the segments between the nodes
What is the tip of the shoot that grows in an elongating direction?
The apical bud
What is an axillary bud?
this is a structure that has the potential to form a lateral branch, thorn, or flower.
What are the 3 specializations of stems?
Rhizomes (root-like) - Underground, horizontal stems
Stolons - aboveground, horizontal stem (strawberry plant), grow along surface and allow plant to reproduce asexually
Tubers - Storage stems (potatoes), enlarged ends of rhizomes or stolons that store food
What are the basic functions of leaves?
The main photosynthetic organ
exchange gases with atmosphere
dissipate heat
defend themselves against herbivores and pathogens
What attaches the leaf to the stem at an axillary bud?
petiole
What is the flattened portion of a leaf called?
the blade
Leaves have vascular tissue that run throughout them, what is the difference of the veins in a monocot and a eudicot?
monocot - parallel veins
eudicot - branching veins
What are some ways that taxonomists will classify angiosperms based on leaf morphology?
simple leaves vs compound leaves
Simple: have a single undivided blade
Compound: have multiple leaflets branching off of petiole
What are 4 specializations that leaves have?
- Spines - perform photosynthesis (cactus)
- Tendrils - support (pea plant), coils around support and brings plant closer to the support
- Reproductive leaves - some make plantlets that fall to soil and take root
- Storage - onions have modified leaves that store food
What are the three tissue systems that are continuous throughout the entire plant (from inside to outside)?
Vascular, ground, and dermal
What is the function of the dermal tissue system?
forms the outer protective covering of a plant
first line of physical defense
What are some modifications of the dermal tissue system?
epidermis - found in NONWOODY plants, epidermal cells closely packed together, exposed to air and covered w/ WAXY CUTICLE which protects them from water loss
Periderm - found in WOODY plants which replaces the epidermis in older regions of stems and roots
Root Hairs - increase surface area of root for water absorption
Trichomes - Protect plant from sun and moisture loss, also discourages herbivory
Guard Cells - control the leaf stomata
What is the basic function of the vascular tissue system of a plant?
to transport materials through the plant and provide mechanical support.
What are the two types of vascular tissue and their basic functions?
Xylem - conducts water and dissolved material upwards from roots to shoots.
Phloem - Transports sugars from where they are made to where they are needed.
What is the name for the COLLECTIVE name for vascular tissue of a root or stem?
Stele