Micro Exam 4 Algae

What does Polyphyletic mean in terms of algae?

non-monophyletic

Where are algae found?

Primarily aquatic, including planktonic, benthic, and neustonic zones.

What is phytoplankton?

algae and small aquatic plants

What is zooplankton?

animals and nonphotosynthetic protists

What are some terrestrial habitats where algae can be found?

On moist surfaces, as endosymbionts in various organisms, and in association with fungi to form lichens.

What are the classical classification schemes for algae based on?

Cellular properties such as cell walls, chlorophyll, and flagella types.

What is the thallus in algae?

The body of an alga, which can vary in form from unicellular to multicellular.

How do algae reproduce asexually?

Through fragmentation, spores (zoospores and aplanospores), and binary fission.

What are pyrenoids?

associated with the synthesis and storage of startch

What is the thallus in algae?

The body of an alga, which can vary in form from unicellular to multicellular.

How do algae reproduce asexually?

Through fragmentation, spores (zoospores- motile and aplanospores- nonmotile), and binary fission.

What are Chlorophyta and what’s special about them?

Green algae can reproduce sexually or asexually. Direct progenitors to land plants. Some have holdfasts (root like structure).

Can be unicellular, colonia, or multicellular.

Live in marine, freshwater, or moist terrestrial habitats.

What key traits suggest a close relationship between green algae and land plants?

Similar chloroplast structure, thylakoid arrangements, cell wall composition, and starch synthesis.

What are the three groups of green algae most similar to land plants?

Zygnematophyceae, Coleochaetophyceae, and Charophyceae.

What is a stigma?

aids in phototaxis

What shape is a Volvox colony?

A hollow sphere.

What organism do Volvox cells resemble?

Chlamydomonas

Where is Prototheca commonly found?

In soil

Why are some Charophyta called "stoneworts"?

They precipitate calcium and magnesium carbonate, forming a limestone coating.

What minerals do some Charophyta extract from water?

Calcium and magnesium carbonate.

What are the earliest eukaryotes to possess the mitochondria?

Euglenoids

What are the characteristics of euglenoids?

1/3rd have chloroplasts

flexible pellicle

no sexual reproduction

no cell wall

What is one characteristic of Stramenopila

Tinsel (hairy) flagella

What are the major groups within Supergroupf of Stramenopila?

Oomycetes

Diatoms

Brown algae

What are Chrysophyta?

Subgroup within stramenopila that includes golden-brown and yellow-green algae and diatoms.

What are special characteristics of Diatoms?

Frustule: silica containing cell wall (like a petri dish)

• Epitheca (the larger half)

• Hypotheca (the smaller half)

What are Phaeophytes?

Brown algae (kelp).

Alternation of generations

multicellular seaweeds

What are Rhodophytes?

Red algae (lacks flagella and centrioles)

Special photosynthetic pigment (phycoerythrin)

Source of agar

Contain Floridean starch

What are Pyrrhophyta?

Dinoflagellates.

What is the ecological significance of diatoms?

They play a crucial role in aquatic ecosystems and contribute to the global carbon cycle.

What are some examples of algae that can cause human health issues?

Toxic dinoflagellates and diatoms can lead to various forms of shellfish poisoning.

What is the role of zooxanthellae in marine ecosystems?

They are unarmored dinoflagellates that live in symbiosis with marine organisms.

What is a Theca?

Protective sheath

What are harmful algal blooms (HABs)?

Toxic blooms of algae that can cause health issues like paralytic shellfish poisoning