Week 3 - Leaves Flashcards
Learn about different kinds of leaf modifications and venation
What is the edge of a leaf called?
Apex
The stalk-like portion of the leaf is the?
Petiole
What are composed of cells that serve in conduction of food and water and to
some degree, in support?
Veins
Leaf venation in monocots is….and in dicots is…. .Some net veined leaves with lateral veins are called….and In other leaves, several strong veins enter the base of a leaf from the petiole and spread
through the blade like the fingers from the hand. These are termed ….
a) parallel ,net-like pattern, pinnately venated , palmately veined
b) net-like pattern, parallel,palmately veined , pinnately venated
c) pinnately venated, parallel venation, palmately veined, net-like pattern
An outgrowth known to be on the inner (upper) surface of the leaf, found between the sheath and blade is called ?
Ligule
The zone at the junction of sheath and blade on the outer (lower) surface is known
as the?
Collar
The blades of compound leaves
are divided into leaflets, each usually with its own small petiole called the ?
petiolule
The arrangement of leaves on the stem is called ?
Phyllotaxy
- leaves one per node
- leaves two per node
- three or more leaves per nodes
- leaves not aligned with their nearest neighbours
a) Alternate, opposite, spiral, whorled
b) Opposite, spiral, alternate, whorled
c) spiral, alternate, whorled, spiral
d) whorled, opposite, spiral, alternate
e) Alternate, opposite, whorled, spiral
e) Alternate, opposite, whorled, spiral
They grow indefinitely and contain cells capable of sensing
contact with another object, what are they ?
Tendrils (leaf tendrils)
The leaves are thick and fleshy, a shape that reduces the
surface-to-volume ratio and favours water conservation., These are ?
Succulent leaves
The term that refers to the expanded petiole of a leaf, often resembling a
more or less parallel-veined leaf in out-look?
Phyllodium or phyllode
Function of phyllodium or phyllode?
Serve the function of a leave
modified leaves by their position just below an axillary bud or shoot on the node, with projections from the margins of blades
Leaf spines
Function of leaf spines
absorb and reflect excessive sunlight and spine tips act as places where dew may condense, drip to the
soil and provide moisture for the plants.
Reduce transpiration
Insectivorous plants usually grow in habitats that are?
Poor in nitrates and ammonia
Specialized leaves that capture and digest insects
Insectivorous plants (leaves)
Trap leaves that move during capture are?
Active traps
Trap leaves that are incapable of movement are ?
Passive traps
Best known trap leaves are ?
Passive traps : Nepenthes sp. (Pitcher plants) and Sarrencia spp.
Active traps : leaves of Venus Flytrap (Dionaea muscipula)
Function of bud scales
Protection for newly formed leaves and branch growth
What is a bud scale?
one of the leaves resembling scales that form the sheath of a plant bud. ( Leaves convert into bud scales)
What is the role of bud scales?
Protection and photosynthesis
Description of bud scales
Waxier and tougher than normal leaves
The rachis is an extension of the ?
Petiole of a compound leaf that bears leaflets
How are leaflets arranged?
Always arranged in rows
Prevention of tearing:
Making the leaf small, tough or compound.
The term phyllodium refers to the ?
Extended leaf base
Has no lamina
Leaves that are sessile lack?
A Petiole
Leaf-like or scale-like structures found at the base of a petiole are?
Stipules
