Why is there so much discussion about green algae (chlorophyta)?
this is the group of algae that is ancestral to all terrestrial plants; without them, there may have been terrestrial organisms that are different than the forms today
They are also populated in variability and forms (appearance)
Why do we thing GA are ancestral?
they have more in common with plants than any other group
- chlorophylls a and b, carotenoids (same as plants)
- major storage food is starch like plants
- some may or may not have flagella (very few terrestrial plants produce flagella)
- green algae (most) have celulose
- coenocytic (multinuclear)
- motile or nonmotile
Characteristics of n
most haploid with signle nuclei; others have many nuclei
- chloroplast varies greatly
- - shape corresponds to shape of the cell
most contain structures like flagella (whiplash or tensel)
Structure found inside chloroplasts: __
- seen in __: How does it look?
- center of __ is __; __ is located around it; common among __.
- spiral with round structures
- green algae
If it is motile, it must have __. It is very common to have __ with __ other than chlorophyll. What does it allow? Which then causes what?
- flagella/ cilia (no cilia in algae)
- an orangey eyespot
- allows detection of direction of light cells and intensity
- respond by moving toward or away (really intense light breaks down chlorophyll)
Even if the adult may not be __, __ can be produced.
Can this occur the other way around?
- motile reproductive cells
What kind of reproduction do they undergo?
asexual (mitosis) and sexual reproduction (isogamous, anisogamous, oogamous)
all three life cycles exhibited(but most common is the alternation of generations)
Majority reside in __.
Can be __ or __; can also __.
Cn live in __.
What is the advantage of green algae to a sloth?
- attached to something
- attach to snow
live in association with other organisms (symbiotic)
Describe their association with trees.
- on trees (moist environment) facing the N side because it receives less light
- unicellular or colonial
Unicelular and motile organisms can be __.
Colonial and motile can be __ (they have a __ around).
- gelatinous matrix
The first life cycle with no diploid organisms (also called __)
What is the difference between the gametes and spores in this one?
plant (n) --(mitosis)--> gametes (n)--(fertilization)--> zygote (only 2n organism) --(meiosis)--> spores (n) --(mitosis- can't do meiosis because there's no pairing of homologs)-->plant (n)
difference: gametes fuse with each other; spores do not)
The second life cycle with no haploid organism (also called __)
plant (2n)--(meiosis)-->gametes (n)--(fertilization)--> zygote (sn)------(mitosis)-----> plant (2n)
Third lifecycle with alternation of generations: both diploid and haploid organisms
Difference between this and the others?
plant (2n)----(meiosis)----> spores not gametes (n)---(mitosis)---> plant (n) ---- (mitosis)--->gametes (n)----fertilization---> zygote (2n)-----mitosis---->plant (2n)
it has two different kinds of individuals; same species
The diploid and haploid plants in an alternation o generations life cycle may: __
Usually one of the two plants __, e.g. a fern is the diploid plant in its life cycle
- 1) look identical
- 2) look completely different and be different sizes
"dominate" the life cycle
In zygomatic and alternation of generations: Gametes produced by __
In gametic mitosis, gametes are made from __.
Plants form gametes by __.
Characteristics of chlorophyta
1) most variable phylum: __
2) __ or __
3) Most __, but some __.
1) unicellular, colonial, filamentous, multicellular, coenocytic
2) motile/ non-motile (adult organism, spores, gametes)
3) uninucleate, multinucleate
1) amount? how large? most contain?
What is a pyrenoid?
1) many;wide variety of shapes; most contain pyrenoids
pyrenoids: proteinaceous core surrounded by starch for food storage
Motile cells (adult, spores, gametes) contain a __; site of __. __.
- red-orange eyespot
1) Most reproduce __.
May be __.
Exhibit which life cycles?
- both sexually and asexually
- isogamous, anisogamous, oogamous
- all three types of life cycles: most haplobiontic, haploid
- some haplobiontic, diploid
- some diplobiontic
a) majority live in __, but some are __.
b) __ or __.
c) May grow on __.
4) A few live on __ (unicellular, non-motile)
e) May live in association with __, e.g. animals, fungi (lichens)
- freshwater, marine
- free-living, attached
- tree trunks
- other organisms
Human Relevance of Chlorophyta (Green Algae)
Used less than __ in most other phyla
Major use is as a __
__: gathered from __ in parts of Asia, Chile, Germany, Iceland. Texture of them is like __. Finely chopped and used in __, __ and __.
- shallow intertidal zones
- wax paper
- soups, salads, relishes
__: a small __ algae that is very easy to culture. Contains most __ humans need except __. In culture, it may produce up to __ and all needed essential amino acids (the building blocks of proteins.
Has an __ and __; without __, may cause physiological problems.
The Japanese process __into a white, tasteless powder that is added to wheat flour.
Cultured in Taiwan and exported to the US, where it is sold in health food stores
- vitamin C
- 50% protein
- unpleasant flavor and texture
Source of __,a precursor of vitamin A
The motile unicellular alga __ produces approximately __ of its dry weight as __. Some species are commercially grown in highly saline ponds or lakes for their __.
__ was considered for use in long-range __. __ could generate __ through photosynthesis using __ produced by astronauts. As the algae multiply, excess could either be eaten or fed to other food organisms, e.g. freshwater shrimp
- space exploration
Some green algae have been used extensively in __, partly because __.
e.g. __ was the first algae to be grown in __ and was used to figure out the __ of the __.
- they are easy to culture
- pure culture
- biochemical pathway
- Calvin cycle of photosynthesis
__ has been important in genetic research.
In the future, some green algae may be used to :
- extract metals from waste water
- produce hydrogen that could be used as a fuel
- production of biofuels (ex: bioethanol)