Gymnosperms

Gymnosperms

Subphylum Spermopsida (seed bearing plants) True roots (with vascular tissue) Reproduction without water (evolved flower) Protective covering around embryo (seed) – can survive winter Improved conducting tissue: thicker and stronger xylem. Became taller.

Class Gymnospermidia ‘naked seeds’ (conifers – cone bearers) 1. Evolved in the early Mesozoic in cooler, isolated areas. 2. Adapted to cool, dry climates; dominant type of tree type in Canada. 3. Leaves = needles. Don’t freeze and carry sap; This allows conifers to continue on with photosynthesis in the winter.

Redwood Trees Sequoia Tree 4. Superior (very thick) xylem; allows for tall growth Sequoia Tree Redwood Trees

5. Cones for reproduction; protects the seeds through the winter 5. Cones for reproduction; protects the seeds through the winter. Airborne pollen eventually pollinates the egg. 6. The seed develops scales and when mature, the scales open and the seed is distributed by the wind.

The cone is made up of a very short branch with many small, rounded,  leaf-like structures (scales) attached to a central stem. A female cone lives and grows for several years, becoming much larger than a male cone. An ovule develops on each scale of a female cone.  Inside the ovule, an egg cell is produced.  If fertilization occurs, an embryo grows inside the ovule.  The ovule hardens, becoming a seed. Eventually the scales spread, allowing the seeds to fall.  If conditions are favourable where it falls, the embryo inside the pine seed will grow into a new tree.

Seedling sporophyte (2N) Adult sporophyte (2N) Gametophytes Seedling sporophyte (2N)

Your question to answer after the song: What do tree rings mean?

(ancient gymnosperms) The Cycads (ancient gymnosperms) Believed to have been the main nourishment for the herbivorous dinosaurs.

WHERE THEY ARE FOUND

Lab Be able to identify: Douglas Fir Yellow Cedar Blue Spruce Ponderosa Pine Engleman Spruce Juniper