Leaves and Modified Structures Flashcards
What is the cell type for photosyntheis
parenchyma cell
monocot vs. eudicot leaves
Monocot: Parallel veins with a uniform mesophyll layer
and large bundle sheath cells in leaf
Eudicot: Net-like leaf veins with distinct palisade and
spongy mesophyll layers in leaf
identify monocot vs. eudicot stomata
Monocot: parallel venation is associated with the uniform distribution of stomata
Eudicot: In eudicot leaves, the arrangement of veins can vary. Eudicots may have reticulate (net-like) venation
petiole
A petiole is a slender, stalk-like structure that connects a leaf to the stem of a plant. It serves as the bridge between the leaf blade (the expanded, flat part of the leaf) and the stem or branch from which the leaf grows.
rachis
central, main axis or stalk that gives rise to smaller structures or appendages, often in a linear arrangement
leafle
a small, individual segment or division of a compound leaf.
differences between simple and compound leaves
Simple leaves have a single, undivided blade, while compound leaves are divided into leaflets.
Simple leaves are attached directly to the stem or branch by a petiole, while compound leaves have a rachis to which leaflets are attached.
Simple leaves are continuous structures, while compound leaves are subdivided into multiple units (leaflets).
The overall shape and venation pattern of simple leaves can vary, but they do not have the distinct leaflet structure found in compound leaves.
Identify pinnate
Leaflets in a pinnately compound leaf are attached to the rachis along its length. The attachment can be opposite (two leaflets at each attachment point, directly across from each other) or alternate (one leaflet at each attachment point, staggered along the rachis).
Identify doubly pinnately compound
a type of compound leaf in which multiple leaflets are arranged along a central stalk or rachis, much like the individual leaflets on the vanes of a feather.
Identify palmate
Leaflets are attached to the petiole at a single point, known as the point of attachment, or the leaf base. The leaflets radiate outward from this central attachment point, resembling the fingers of a hand or the lobes of a palm leaf.
What are the leaf venation types and identify them
Parallel Venation (Parallel-Pinnate Venation):
Description: In leaves with parallel venation, the major veins (veins that carry water and nutrients) run parallel to each other, often in a uniform manner from the base of the leaf to the tip.
Examples: Parallel venation is commonly found in monocots, which include grasses, lilies, and orchids. Grass leaves, for instance, have prominent parallel veins.
Reticulate Venation (Netted Venation):
Description: Reticulate venation, also known as netted venation, is characterized by a branching pattern of veins, forming a network of interconnected veins throughout the leaf.
Examples: Reticulate venation is common in eudicots, which are one of the two major groups of flowering plants. Many trees, shrubs, and broadleaf plants, such as oaks and maples, have reticulate venation.
Palmate Venation:
Description: In palmate venation, several major veins radiate outward from a single point of attachment at the base of the leaf, much like the fingers of a hand radiating from the palm.
Examples: Palmate venation is often found in palmately compound leaves, where leaflets are attached to the petiole at a single point. Examples include the horse chestnut and poison ivy.
What are the leaf arrangment terms
Alternate: In an alternate leaf arrangement, a single leaf is attached at each node along the stem, alternating sides as you move up the stem. This arrangement creates a staggered pattern along the stem.
Opposite: In an opposite leaf arrangement, two leaves are attached at the same node along the stem, directly across from each other. This arrangement creates a paired pattern along the stem.
Whorled: In a whorled leaf arrangement, three or more leaves are attached at the same node along the stem, forming a circular or star-like pattern around the stem. The leaves radiate from a central point.
Rosulate: Rosulate leaf arrangement is a specific type of whorled arrangement where leaves form a tight rosette or cluster at the base of the stem, often close to the ground. This is common in plants like dandelions.
Spiral: In a spiral leaf arrangement, leaves are attached in a spiral pattern along the stem, with no specific pattern or regularity in the spacing between leaves. This arrangement is less common and can be challenging to discern.
