biodiversity of plants Flashcards
Currently there are different plant species on earth, which are said to have emerged from
a simple unicellular algae. These plants have been classified into four plant groups
namely:
- Bryophytes- mosses, liverworts, and hornworts
- Pteridophytes-ferns
- Gymnosperms- conifers, cycads, ginkgo biloba and pine tree
- Angiosperms- flowering plants
BRYOPHYTES
examples
Mosses,
liverworts & hornworts
bryophtyes
Structure of dominant generation
- Thallus plant: no true roots, stems or leaves
- Gametophyte is dominant
- Leave-like structures, stem-like structures and rhizoid
bryophytes vascular tissues
no xylem or phloem tissues
bryophytes spores/seeds
Sperm cells and egg cells in male and female reproductive organs.
Spores: spread through wind
No seeds
bryophytes fruit bearing
dont bear fruit
bryophytes dependancy on water for reproduction
needs water for reproduction, sperm swim in water
PTERIDOPHYTES example
frens
pteridophytes : Structure of dominant generation
- True leaves, roots and stem
- Sporophyte is dominant
- Gametophyte: Prothallus
- Roots: adventitious roots
- Leaves: monocot Leaves (sessile leaves) & dicot leaves (attached to petiole)
sessile leaves
Plants that have their leaves directly connected to the stem have sessile leaves.
They lack a leaf stalk (petiole) that attaches a leaf to the stem.
Examples of plants with sessile leaves are grass plants, achyranthes, saffron, etc.
pteridophyte, vascular tissues
Possess
xylem
and
phloem
pteridophyte, seeds and spores
Sperm and egg cells onprothallus
No seeds
pteridophyte fruit bearing
non fruit bearing
pteridophytes dependancy on water for reproduction
need water for reproduction
which diagram best explains the evolutionary chain of plant growth
phylogenetic trees
fern root thingies
rhizoid
