Most algae are photoautotrophic and carry on photosynthesis. Some forms, however, are chemoheterotrophic and obtain energy from chemical reactions and nutrients from preformed organic matter. Most species are saprobes, and some are parasites.
Reproduction in algae occurs in both asexual and sexual forms. Asexual reproduction occurs through the fragmentation of colonial and filamentous algae or by spore formation (as in fungi). Spore formation takes place by mitosis. Binary fission also takes place (as in bacteria).
During sexual reproduction, algae form differentiated sex cells that fuse to produce a diploid zygote with two sets of chromosomes. The zygote develops into a sexual spore, which germinates when conditions are favorable to reproduce and reform the haploid organism having a single set of chromosomes. This pattern of reproduction is called alternation of generations.
while seed plants have the following charactriestics
All seed plants have seeds which contain an embryo, a seed coat and stored food. The seed coat protects the seed, allowing it to remain dormant until the weather is just right for germination. At that point, the leaves of the embryo absorb water and the radical or root emerges, shortly followed by the plumule or shoot. The stored food nourishes the seed, allowing it to thrive until it becomes fully established.
Seed plants all have vascular systems consisting of xylem and phloem. Food is produced in the flood and moves through tubes called the phloem, which distribute it through the plant, giving the cells energy. The xylem, on the other hand, bring water up from the roots, keeping the plant hydrated and enabling photosynthesis.
All seed plants have some means of dispersal
to scatter their seeds at a distance from the mother plants, ensuring
that offspring will grow and spread. Many seed plants use fruit for
disposal. Birds, mammals and other animals eat the fruit, swallowing the
seeds. Later, the mammals excrete the seeds, depositing them in a new
location where plants can spring up.
- Most fungi grow as tubular filaments called hyphae. An interwoven mass of hyphae is called a mycelium.
- The walls of hyphae are often strengthened with chitin, a polymer of N-acetylglucosamine. ...
- Fungi disperse themselves by releasing spores, usually windblown. ...
- Fungi are heterotrophic.
- adaptation that makes each colonies land
2) Structural support (cellulose & lignin) also roots as both anchors and a means of extracting water (& soluble nutrients) from soil.
3) Vascular nutrient movement rather than passive diffusion
4) Reproduction – pollen & seeds - haploid life stage become reduced then miniature. Central cell, double fertilization so the zygote has endosperm- the seed. Protected seeds in ovaries and floral symbioses with pollination partners.
What morphological trait was lost in plants and fungi but may have been
present in the lineage leading up to fungal and animal lineages?
long as ecological interactions are maintained; (2) by analysing known cases of trait loss, specific factors
promoting compensated trait loss can be identified and (3) genomic sequencing is a key way forwards in
detecting compensated trait loss.
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