Read Cambium, Wood and Bark
Lateral meristems add secondary tissues and produce wood, bark and seasonal growth rings.
Living-system questions are solved by matching a structure or organism to its function, process and stated condition.
Track the cambia
Vascular cambium adds secondary xylem inward and secondary phloem outward. Cork cambium (phellogen) produces phellem outward and phelloderm inward; the periderm replaces the outer epidermis.
Read the wood
Sapwood is functional younger xylem that conducts water; heartwood is older and often darker. Primary xylem remains innermost as secondary xylem accumulates outward. Earlywood and latewood together make annual rings; clear seasonal differences produce more distinct rings. Bark includes living and non-living tissues.
OlympIQ exam lens
- ✓Vascular cambium: secondary xylem in, phloem out.
- ✓Phellogen: phellem outward, phelloderm inward.
- ✓Sapwood conducts; primary xylem remains central.
- ✓Annual rings reflect seasonal growth.
An annual ring is one year of secondary xylem, not a mixture of heartwood and sapwood.
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