Phylum Chrysophyta (Kenai and Laura)

Phylum Chrysophyta

Golden Brown Algae: Reproduction

• Reproduce by means of cell division or production of a zoospore

• Cell division - the process by which an entirely new organism is produced in some unicellular organisms
• Zoospore - an asexual organism that moves by use of a tail-like projection or flagellum

Golden Brown Algae: Cell Wall

• Have diverse structures that resembles to the roots, leaves and stalks of a true plant

• Cell walls are made of cellulose

• Outsides of the walls are covered by a gelatinous pectic compound call algin

Diatoms: Cell Wall

• Named frustule

• Have double shells, or frustules that are largely constructed of silica or silicon dioxide

Golden Brown Algae (Chrysophyceae)

• Cell wall very hard/excellent protection to the diatom

• Two main shapes: pennate and centric

• Distinguished on the basis of the shape of their frustules

• Less diverse than the diatoms

• Remains of the cell wall clump together and form diatomaceous earth or diatomite

Diatomaceous earth

• Huge deposits of diatomaceous earth exist in most regions of the world

• Laid down during the flood (creation scientists' belief)

• Used for many purposes
• ex: filtering liquids/abrasive(toothpaste/insects)

Diatoms: Reproduction

• Some species lack cell walls others have pectin-rich walls

• Asexual reproduction

Diatoms

• Nuclear and cytoplasmic division

• Daughter cells each have only one wall and half the volume of the parent cell

• Important in the open waters of the oceans

• Unique type of algae

• Thus daughter cell is smaller than the parent

• Continued asexual reproduction results in reduction of their size

• Single-celled eukaryotic organism

• Control the productivity and biomass of the especially tiny size fractions of the phytoplankton

• Normal cell size is restored by discarding the old walls and reproducing sexually, first forming a zygote and new walls

• Genetic information secluded into sub-cellular compartments called nuclei

• Distinct because they form complex outer cell walls, sometimes called skeletons

Continued...

• Initially categorized as plants

• Most are photosynthetic but require an exogenous source of vitamins for growth

The Major Classes of Chrysophyta

Yellow Green Algae: Cell Walls

• Most xanthophytes produce a cell wall

• Many cases some become heterotrophic when there is inadequate light or if dissolved food is plentiful

• not usually composed of cellulose (plants) or of chitin (fungi)

• Diatoms (Bacillariophyta)

• Most often found in similar cases to diatoms (two cylindar halves that fit together)

Yellow-Green Algae (Xanthophyceae)

• Many found are sessile or free-living (colonial)

• Live as naked cells in a gelatinous envelope or in filamentous forms

• Golden Brown Algae (Chrysophyceae)

• Produce long chains of cells

• Includes more than 600 species

• Yellow Green Algae (Xanthophyceae)

• Generally are not abundant when they are found

• Many species have only been found once

• Lack the brown pigment fucoxanthin (unlike other chromists)

• Instead they have chlorophyll c

Chrysophyta: A Summary

• Gives them a yellowish-green color

Yellow Green Algae: Reproduction

• Makes them difficult to recognize as chromists

• Usually asexual

• This is a unicellular marine or freshwater organism within the kingdom protista

• Sporangium forms (1st step)

• Cross wall develops at base of parent organism and new organism (2)

• No specific cell wall type

• A single zoospore emerges through an opening

• New separated zoospore begins creating a new filament

• Reproduce asexually and sexually

• Important factor of the plankton and nanoplankton that form the foundation of the marine food chain

Breakdown of the Presentation

Works Cited

• Description of what Chrysophyta

• The major classes of Chrysophyta (Diatoms)

http://www.encyclopedia.com/topic/Chrysophyta.aspx#1

http://www.ucmp.berkeley.edu/chromista/chrysophyta.html

https://microbewiki.kenyon.edu/index.php/Chrysophyta

https://prezi.com/khpoxnrmobg6/phylum-chrysophyta/

http://lifeofplant.blogspot.com/2011/05/chrysophytes.html

http://www2.mcdaniel.edu/Biology/botsyl01/microalg/diatomsf/diatoms.htm

http://science.jrank.org/pages/205/Algae.html

http://www.ucmp.berkeley.edu/chromista/xanthophyta.html

• Food habits of this organism

• Habits of reproduction

• Cell wall structure

• Living Area

Chrysophyta: Habitat

• Predominantly found in freshwater environments

• Few found in marine or soil and snow

• Widely distributed in mostly cold-temperate lakes, ponds, bogs, and ditches

• Some species are common members of the phytoplankton, and nanoplankton that is the foundation of the aquatic food chain

• ex: Dyno Byon - contains algae that form colonies called holdfasts.

• holdfasts - def: a special structure used by an organism to anchor itself.

• They form long strands that attach to a surface in the water

• Allows the colony to not be at the mercy of the currents

• When a colony use holdfasts, it is called a sessile colony.

• Sessile colony - a colony that uses holdfasts to anchor itself to an object.