plant organs: Stems Flashcards
what are the four primary functions of stems
support, translocation, photosynthesis, and storage
what does the stem support
the green tissues (leaves)
what are some ways stems can grow
erect, twining, or prostrate
what is responsible for translocation in the stem
the vascular bundle, also known as the xylem and phloem
what is an example of a plant that has poorly developed leaves so the stem in the main place of photosynthesis
cactus
in some plants what can stems also be modified as
food storage
ex. sugar cane, asparagus
how do stems grow and develop
stems contain meristems which develop leaves, branches, tillers, adventitious roots, and buds
what are the internodes
the distance from one node to another
how are dicot vascular bundles arranged
in a circle around the central pith core
what do dicot stems have to increase girth
vascular cambium
what does the node do in dicots
it is a place of attachment for one or more leaves as well as buds which can grow into branches
how do monocots increase their thickness
by cell expansion (not cell division)
how is the vascular bundle arranged in monocots
they are scattered throughout the outer layer of pith
the stems are usually ____ in monocots
hollow
monocot nodes are usually ____
solid
where do leaves originate in monocots
at the nodes
in monocots where is the meristem located
the base of the leaf
how are leaves attached in monocots
attached at the nodes by a sheath
how are the leaves attached in dicots
directly at the node or by petiole
what are tillers and what causes them to grow
they are side shoots. the ability to produce tillers is controlled by genetic and environmental conditions
what are environmental conditions that can increase tilling
when plants are placed further apart they have an increased light penetration causing more tilling.
optimum amounts of food and water are also important
what is apical dominance in plants and how is it caused
the top of the plant is the main point of growth.
it is caused by hormones in the plant apex.
this results in the formation of branches from the buds along the stems
in apical dominance what happens if the apex is removed
allows the lower buds to develop more lateral branches
when is apical dominance beneficial and not beneficial
it is undesirable in trees (would cause them to grow tall in weird ways)
beneficial in scrubs (you can make them dense and full)
what is the axillary bud
the bud found in the leaf axil
what is the axil area
the upper angle created between leaves at the point of connection with a stem. its where the axillary bud is found
what is the stem of a cereal crop called
culm
after 4-5 leaves have been produced on a cereal plant what will happen
it’ll begin to tiller
what is a tiller
aside shoot that is produced when the axillary bud at a stem node breaks dormancy and begins to grow
after the tiller produces about tree leaves ut generally begins to develop its own secondary adventitious roots from lower stem nodes
