Ch. 18 Part 2

Question 1

Phylum Dinophyta

Answer 1

o Dinoflagellates
o Red tides: sudden multiplication of dinos
o Some produce neurotoxins that accumulate in shell fish
o Cellulose “armor plates” inside cell membrane
o Two flagella in intersecting grooves
o One trails behind cell- acts as rudder

Question 2

Key features of phylum dinophyta

Answer 2

 Disc shape chloroplasts
 Xanthophyll pigments
 Chlorophyll a and c
 45% non photosynthetic
 Chromones remained condensed and visible throughout cell life
 Starch food reserve
 Tiny projectiles that fire when irritated

Question 3

Phylum Cryptophyta

Answer 3

o Marine and freshwater
o Two flagella
o Plates on inside of plasma membrane
o Single two-lobed chloroplasts with starch granules surrounding a central pyrenoid
o Nucleomorph: vestigial nucleus of primitive symbiotic organism
o Gullet lined with ejectosomes
o Sexual reproduction unknown

Question 4

Phylum Prymnesiophyta (haptophyte)

Answer 4

o Freshwater and saltwater
o Major component of marine plankton
o Most unicellular
o Two smooth flagella of similar length inserted at the apex
o Pigments and food reserve similar to chromophyta
o Haptonema: third flagellum

Question 5

Charophyta

Answer 5

o Stoneworto Shallow freshwater lakes
o Ponds
o Often precipitate calcium salts on surfaces
o Axis with short lateral branches in whorls
o Sexual reproduction is oogamous
 Male gamete is mobile and female gamete immobile
o Multicellular antheridia

Question 6

Phylum Myoxmycota

Answer 6

o Plasmodial slime molds
o Without chlorophyll
o Geed on bacteria and other organic particles
o Consists of plasmodium
 Protoplasm containing many diploid nuclei
 No cell wall
 Flows rapidly and rhythmically
 Found on damp forest debris, under logs, on dead organic material
o Sexual reproduction
 Plasmodium converts inti separate small sporangia that contain spores
 Many diff forms are seen in diff species
 Spores often distributed in mass of threads called capitellum

Question 7

Dictyosteliomycota

Answer 7

o Individual amoebalike cells feed independently
o Clump and move in pseudo plasmodium mass
o Crawls like garden slug
o Transforms in sporangium like mass of spores

Question 8

Oomycota

Answer 8

o Water molds
o Cottony growth on fish
o Dead insects found there
o Range from spherical cells to branching coenocytic hyphae
o Coenocytic hyphae are not divided into individual cells and may form large thread masses *mycelia)
o Share features with brown algae
 Oogamy
 Cellulose
 Zoospores with two flagella
 Diploid lifestyle
o Downy mildew on grapes
o Potato blight
o 1846 famine in Ireland