Stems Flashcards
What is a stem?
a plant organ consisting of nodes and internodes
What is a node?
the point leaves are attached on a stem
What is an internode?
the stem segments between nodes
What is the 3 main purposes of a stem?
Structure, protection, and transport of nutrients
How does the stem provide structure?
the stem holds up the plant allowing it to grow towards the light
How does the stem provide protection?
thorns, bark
How does the stem transport nutrients through the plant?
Vascular tissue transport water and other nutrients through the plant
What is an apical bud?
The growing shoot tip that grows long
What is an axillary bud?
lateral growth, branch, thorn or flower
What are the two types of stems
herbaceous and woody
What is wood?
a natural composite of cellulose fibers embedded in a matrix of lignin
what are meristems?
a region of undifferentiated cells that produce new tissues through cell division
What does it mean when meristems are dormant?
they are regions the have the potential to develop new stems, leaves and roots but are in “arrested development”
what does it mean when meristems are active
the meristems are growing into new stems, leaves, and roots
What is primary growth?
growth in length
What is secondary growth?
growth in thickness
what plants have secondary growth?
secondary growth occurs in gymnosperms and many true dicots, but is rare in monocots
What parts of the plant experience secondary growth?
stems and roots rarely the leaves
What does secondary growth consist of?
tissues in the vascular cambium and cork cambium
do primary growth and secondary growth occur at different times?
no they are simultaneous
What is the anatomy of a tree trunk?
Bark, vascular cambium, and secondary xylem
What does the bark consist of?
layers of periderm, and Secondary phloem
What is the use of the layers of periderm?
Protection from disease and pests, insulation from fire
What is the use of the phloem?
they are living cells that conduct nutrients down the tree
