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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)
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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
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Body types
- unicellular
- colonial
- coenocytic (multinuclear)
- filamentous
- motile or nonmotile
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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)
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Structure found inside chloroplasts: __
- seen in __: How does it look?
- center of __ is __; __ is located around it; common among __.
- pyrenoids
- spirogyra
- spiral with round structures
- pyrenoid
- protien
- starch
- green algae
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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
- pigments
- allows detection of direction of light cells and intensity
- respond by moving toward or away (really intense light breaks down chlorophyll)
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Even if the adult may not be __, __ can be produced.
Can this occur the other way around?
- motile
- motile reproductive cells
- no
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What kind of reproduction do they undergo?
Life cycles?
asexual (mitosis) and sexual reproduction (isogamous, anisogamous, oogamous)
all three life cycles exhibited(but most common is the alternation of generations)
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Majority reside in __.
Can be __ or __; can also __.
Cn live in __.
What is the advantage of green algae to a sloth?
freshwater
- attached to something
- float
- attach to snow
live in association with other organisms (symbiotic)
camouflage
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Describe their association with trees.
- on trees (moist environment) facing the N side because it receives less light
- unicellular or colonial
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Unicelular and motile organisms can be __.
Colonial and motile can be __ (they have a __ around).
- chlamydomonas
- pandorina
- gelatinous matrix
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The first life cycle with no diploid organisms (also called __)
What is the difference between the gametes and spores in this one?
zygotic meiosis
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)
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The second life cycle with no haploid organism (also called __)
plant (2n)--(meiosis)-->gametes (n)--(fertilization)--> zygote (sn)------(mitosis)-----> plant (2n)
gametic meiosis
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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
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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
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In zygomatic and alternation of generations: Gametes produced by __
In gametic mitosis, gametes are made from __.
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Plants form gametes by __.
mitosis
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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
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Chloroplasts:
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
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Motile cells (adult, spores, gametes) contain a __; site of __. __.
- red-orange eyespot
- light
- perception
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Reproduction
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
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Habitat
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
- snow
- tree trunks
- other organisms
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Human Relevance of Chlorophyta (Green Algae)
Used less than __ in most other phyla
Major use is as a __
algae
food source
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__: gathered from __ in parts of Asia, Chile, Germany, Iceland. Texture of them is like __. Finely chopped and used in __, __ and __.
- Ulva
- shallow intertidal zones
- wax paper
- soups, salads, relishes
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__: 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
- Chlorella
- unicellular
- vitamins
- vitamin C
- 50% protein
- unpleasant flavor and texture
- purification
- Chlorella
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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 __.
- beta-carotene
- Dunaliella
- 14%
- beta-carotene
- beta-carotene
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__ 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
- chlorella
- space exploration
- Chlorella
- O2
- CO2
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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 __.
- research
- they are easy to culture
- Chlorella
- pure culture
- biochemical pathway
- Calvin cycle of photosynthesis
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__ has been important in genetic research.
Acetabularia
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In the future, some green algae may be used to :
(three things)
- extract metals from waste water
- produce hydrogen that could be used as a fuel
- production of biofuels (ex: bioethanol)
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