PHYLUM GYMNOSPERMOPHYTA
1.
Observe living conifers on campus. Notice the types of leaves, distribution of
leaves, and the pattern of branching.
2.
Does "conifer" always mean "evergreen"? Answer with at least one example.
3.
Examine cuttings, herbarium sheets, and preserved conifer plants on
demonstration.
4.a.
Study the cross sectional aspect of a Pinus 5-needle leaf and label the epidermis,
hypodermis, sunken stomata, mesophyll cells, and endodermis. Add vascular
tissue to the illustration. Indicate those tissues with chloroplasts.
4.b.
Examine a Pinus 1-year stem section and label: periderm, cortex, resin canals,
primary and secondary xylem, rays, primary and secondary phloem, pith, and
cambium.
4.c.
Now study cross, radial, and tangential sections of Pinus wood.
4.d.
How do the rays appear in each section?
4.e.
Look for tracheids with bordered pits. Be able to explain the organization and
function of the bordered pits.
4.f.
Observe a Pinus root cross section slide and describe secondary growth, if
present.
4.g.
Label the zones of tissue in the drawing below.
4.h.
Add rays to the drawing.
4.i.
Does the root have pith?
4.j.
Do you see resin canals?
4.k.
Observe a male strobilus longitudinal section. Sketch microsporangia into the
drawing below.
4.l.
What describes the position of the microsporangia relative to the sporophyll?
4.m.
Now observe a male strobilus cross section. How many microsporangia are borne
on each microsporophyll?
4.n.
Observe the longitudinal section of a young ovulate cone scale. Add a bract,
megasporangium, megasporocyte, and pollen grains to the drawing.
4.o.
How are the megasporangia positioned on the cone scales?
4.p.
What is the approximate ages of the ovulate cone slides?
4.q.
Examine slides of a free-nuclear gametophyte and a mature gametophyte with
archegonia. Add archegonia, a megasporangium, megagametophyte(s), pollen
grains, and pollen tubes to the drawing below. If pollen with pollen tubes are not
present on your slide, look at the proembryo slide.
4.r.
Observe a seed with a mature embryo. How many sporophytes do you see?
4.s.
Which way relative to the nucellar end has the embryo grown?