27: secondary growth Flashcards
which meristem has cells that are actively dividing?
shoot apical meristem
disadvantages of growing tall?
- more support is needed
- more leaves = requiring more transport capacity
- apical growth is no longer a problem solver
what is the solution to the tall problem?
increasing the diameter provides more support and transport tissues
most of a plant’s volume is generated by?
elongation of cells
lateral meristems
add thickness to woody plants in secondary growth
2 types of lateral meristems?
- vascular cambium
- cork cambium
vascular cambium
adds layers of secondary xylem (wood) and secondary phloem
cork cambium
replaces the epidermis with the periderm - basically the bark
secondary growth is a characteristic of?
seed plants like gymnosperms and eudicots
secondary growth occurs in?
the mature stem
___ interweave in secondary vasculature, enabling lateral transport
rays
what develops from undifferentiated parenchyma cells?
the vascular cambium + secondary vascular tissue
in a woody stem, the vascular cambium is located?
outside the pith and primary xylem, but inside the primary phloem and cortex
in a woody root, the vascular cambium forms exterior to the ___ and interior to the ___ and ___
primary xylem, primary phloem and pericycle
early wood formed in spring has thin cell walls to maximize?
water delivery
later wood formed in late summer has thick wall cells to contribute more?
stem support
dendrochronology
the analysis of tree ring growth patterns, can be used to study climate change
soft wood
uniform texture (conifer)
hard wood
variable texture with color variations (dicots)
sap wood
actively conducting, lighter in color
heart wood
no longer conducting, darker in color
what cells within the root also contain suberin?
endodermis
which diameter is larger, vessel element or tracheid?
vessel element
which wood is predominated by tracheids and small amount of parenchyma?
soft wood
