Gymnosperms Flashcards
How was “gymnosperm” coined
From two latin words : gymnos = naked, and
sperma = seed
What’s the main difference between gymnosperms and angiosperms
The major difference between the two groups of seed plants (Gymnosperm
and Angiosperm) are:
1. Gymnosperms seeds are not enclosed, while that of the angiosperms are.
Reproductive structure of gymnosperms are?
Their reproductive structure are cones
When did the gymnosperms developed
They developed in the palezoic era (3500mya-299 mya}) and become the dominant seed plant in the mesozoic era (145mya)
Examples of gymnosperms
Conifers, cycads, gingkos, gnetophytes
Smallest gymnosperm
Zamia Pygmea
Tallest and largest gymnosperm
Sequoia sempervirens
Also the tallest tree.
The largest plant is also a conifer callled giant sequoia (sequoiadendron gigantum)
Life cycle of gymnosperms
Shows alternation of generation.
Dominant phase is the sporophyte
Arrangement of sporophylls in gnosperms
They’re arranger on a central axis in form of cone/strobilus
Ancestral history of the gymosperms
They’re said to developed from a group, the pteridosperms (seeded ferns)
True fern?
They reproduce from spores not seeds
About cones
They’re unisexual
Are gymnosperms homosporous or heterosporous
They are heterosporous i.e the produce both male and female spores(gametophytes)
Thickest tree
The thickest treewith greatest trunk diameter is Montezuma cypress
(Taxodium mucronatum)which is 11.5m in diameter.
