Angiosperm Morphology and Meristems Flashcards
What are 2 seed bearing plants?
Gymnosperms (Cone bearing plants)
Angiosperms (Flowering plants)
What does Gymnosperm means ?
What about Agiosperm?
Gymnosperm means naked seed.
Angiosperm means enclosed seed
Describes all Dicots characteristic:
- Two seed leaves
- Netted leaf veins
- Flower parts in 4s & 5s
- Primary taproot
- Stem vascular bundles are in a ring
- Pollen mostly tricolpate (three pores)
> 50% are woody
Describes all Monocots characteristic:
-One seed leaf
-Parallel leaf veins
- Flower parts in 3s
- Fibrous root system
- Stem vascular bundles are scattered
- Pollen mostly monosulcate (single pore)
< 10% woody
Dicots Morphology & Meristem:
shoot system above ground : leaves, stems, buds, flowers, fruits.
Root system below ground: roots
What is the meristem?
A tissue that contains
actively dividing cells.
What are the 4 types of meristem ?
- Apical Meristems
- Axillary buds have axillary meristems
- Lateral meristems
- Intercalary meristems
What is the Apical Meristems?
The apical meristem is a primary
meristem which through cell division adds
to the shoot length (height). Situated at the top of shoot tip’s plant.
What each leaf consist of ?
Each leaf consists of a blade (lamina) and
stalk (petiole) and attaches to the stem at
a node.
What is region of stem between two nodes?
internode
What is between leaf petiole and the stem ?
An Axillary bud (contains an axillary meristem).
Axillary bud
- Can give rise to an axillary branch or flowers
- Axillary buds may remain dormant – under
hormonal control (Auxins)
What the root system consist of ?
- The root system consists of a primary or tap root and a series of lateral roots branching from it.
- At the tip of each root is a root apical meristem, a primary meristem adding to root length.
Monocot Morphology :
When shoot is vegetative, the shoot apex (apical meristem) is very close to soil level and not obvious (a protected meristem)
* The vegetative apical meristem produces leaves inserted at nodes - the internodes are very
short, 1 to 2 mm, so no obvious stem.
Monocot morphology in Grasses :
- Leaves consist of a blade and a sheath
- There is an axial (axillary)
bud in each leaf axial which can give rise to a branch (tiller).
What is a tiller ?
Basic unit of a grass, arise from axillary buds
located at basal apical meristem, refer to all shoots that arise after initial parental shoot grow from seed.
Monocot Root system :
- Fibrous root system.
- Initial seminal root
system (seed roots) are
replaced with an adventitious root system
that arises from the nodes
at the base of the stem.
What is an Intercalary meristem ?
What it does ?
Where does it occurs ?
-It’s a meristem between two differentiated tissues.
-Facilitates longitudinal growth of plant organ.
pical meristem.
-Occur in the region of the nodes of grasses and are
responsible for (stem) culm extension.
What happens when the grass plant becomes
reproductive ?
- The apical meristem
stops producing leaves and forms into the flowering structures - The internodes elongate and push the flowers upwards on the true stalk or culm.
What is lateral meristem ?
What it does ?
- Vascular cambium and cork cambium are lateral meristems.
- Produce tissues that increase the girth (diameter/width) of roots and stems (secondary growth).
What the vascular cambium produces?
Produces additional vascular tissue, secondary xylem and secondary
phloem.
What the cork cambium produces in woody species?
In woody species, the cork cambium produces the outer bark.
