Characteristics
- usually terrestrial (they are the most important terrestrial producers)
- multicellular
- eukaryotic
- cellulose cell wall
- chloroplasts (which contain chlorophyll a and b as primary pigments and carotenoids and xanthophylls as accessory pigments)
- autotrophs
A very generalized plant cell looks like this:
Image from http://leavingbio.net/CellStructure_files/CellStructure.htm
The simplest plants (eg. mosses) are thalloids (telepes) - like in algae and fungi - and while their cells may exhibit different shapes and functions, they are not particularly specialized and don't form large groups of specialized cells (tissues -szövetek).
In higher plants, cells are specialized for different functions - groups of specialized cells form tissues (plant parts). Cells found in different tissues will have different characteristics based on their function.
In higher plants, cells are specialized for different functions - groups of specialized cells form tissues (plant parts). Cells found in different tissues will have different characteristics based on their function.
eg. vegetative parts: root, stem, leaves; reproductive part: flower
Origin
- move from water to land occurred about 500 million years ago
- green algae on the edges of seas and oceans slowly adapted to life on land
- advantages to life on land: more light, more CO2, less competition
- the first land plants may have looked like mosses, we don't know for sure because there is no fossil record
- 1st fossils are about 400 million years old: psilophytes
Images from http://blass.com.au/definitions/psilophyte
Adaptations to land:
1. epidermis (bőrszövet) - covers outside, prevents drying out
2. vascular tissue (szállítószövet) - to transport nutrients between roots, stem and leaves
3. supporting tissue (támasztószövet)
4. reproduction independent of water - gamete dispersal by wind or animals
Reproduction in plants
- alternation of generations (see previous notes)
- in plants the sporophyte and gametophyte usually look different from each other
- in mosses the gametophyte is dominant, in higher plants the sporophyte is dominant and the gametophyte is found in the reproductive part of the plant
Classification
- non-vascular plants (edénytelen növények) eg. mosses
- vascular plants (edényes vagy hajtásos növények)
a) non-flowering plants eg. ferns (use spores for reproduction)
b) flowering or seed plants (virágos vagy magvas növények)
b1) gymnosperms or conifers (nyitvatermők) eg. pine tree
b2) angiosperms or flowering plants (zárvatermők)
b2i) monocots (egyszíkű) eg. grasses
b2ii) dicots (kétszíkű) eg. roses
Image from http://www.emc.maricopa.edu/faculty/farabee/biobk/biobookdiversity_5.html
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