Notes on Brown/Red Algae, Reproduction, Eukaryotes, Green Algae, and Bioluminescent Dinoflagellates

Brown Algae

Structurally complex; can be filamentous or multicellular. Pigment: Fucoxanthin. Size range: microscopic to over $50\ \mathrm{m}$ long. Important as a food source and provides alginic acid.

Fucoxanthin

The brown pigment found in Brown Algae.

Alginic Acid

A product derived from Brown Algae, used as an emulsifier in various industries.

Red Algae

Multicellular algae. Pigment: Phycobilins (red photosynthetic pigment) in plastids. Growth forms: attached or free-floating, filamentous or fleshy. Derived products: Carrageenan and Agar.

Phycobilins

The red photosynthetic pigment found in Red Algae, giving them their red coloration.

Carrageenan

A product derived from Red Algae.

Agar

A product derived from Red Algae.

Asexual Reproduction (Algae)

Occurs through mitosis.

Sexual Reproduction (Algae)

Occurs under unfavorable conditions; involves syngamy (fusion of haploid gametes) to form a diploid zygote, followed by zygospore formation and meiosis to produce four haploid individuals.

Syngamy

The pairing and fusion of morphologically similar haploid gametes to form a diploid zygote ($n + n \rightarrow 2n$).

Zygospore

A structure formed after gamete fusion, which then undergoes meiosis to produce four haploid individuals ($2n \xrightarrow{\text{Meiosis}} 4\,n$).

Domain Eukarya

Organisms characterized by having membrane-bound nuclei. Includes four kingdoms: Protista, Fungi, Plantae, and Animalia.

Green Algae (Chlorophytes)

The most diverse group of freshwater algae. Share traits with plants: cell walls made of cellulose, chlorophylls $\mathrm{a}$ and $\mathrm{b}$, and starch as carbohydrate storage material. Growth forms: unicellular, filamentous, or colonial.

Bioluminescent Dinoflagellates

Dinoflagellates that produce a bioluminescent glow, often highlighted in nature programs.