Chapter 22: Protists

Question 1

1. Characteristics of Excavates

Answer 1

•Hollow ventral feeding groove •Single cell w/ flagella •Lack Mitochondria -> Adaption to parasitism

Question 2

1a. Diplomonoadida (double cells)

Answer 2

(double cells)

• two nuclei
• multiple symmetrical flagella
• some free living
• some parasites

Question 3

1b. Parabasalia (parasitic)

Answer 3

(parasitic)

• flagella buried into cytoplasm
• undulating membrane -> Moves through viscous fluids Parabasal bodies (the Golgi apparatus of the cell)

Question 4

2. Characteristics of Dicicristates

Answer 4

Protozoa - ingest food and move (animal like)

• Disk-shaped mitochondrial cristae
• Single-celled
• Highly Motile Flagella
• Most photosynthetic
• Some parasitic

Question 5

2a. Euglenoids

(Eu- “good”) (-glen- “eye”)

Answer 5

• (freshwater)
• Most are autotrophs
• Photosynthetic
• Pellicle
• 2 Flagella
• Eyespot
• Movement

Question 6

2b. Kinteoplastids

Answer 6

• Heterotrophs
• Animal parasites
• 2 flagella
• kinetoplast
• Large DNA and protein deposit

Question 7

3. Characteristics of Alveolates

Answer 7

•Small, membrane bound vesicles called alveoli under plasma membrane

Question 8

3a. Ciliophora

Answer 8

• Heterotrophs
• Swim using Cilia
• Complex cytoplasmic structures
• Pellicle Has two nuclei
• Micronucleus (all genes- reproduction)
• macronucleus (some genes- metabolism)
• Some parasitic
• some Symbionts

Question 9

3b. Dinoflagellata

Answer 9

• Shell of cellulose plates
• spin-like swim using flagella
• primarily marine
• autotrophs and heterotrophs
• Phototrophs
• Major primary producer (corals depend on them)
• Some are bioluminescent
• Some cause red tides
• When coral stressed- coral bleaching

Question 10

3c. Apicomplexa

Answer 10

• Non-motile animal parasites
• Apical complex - attach and invade host cells •reproduction: both sexual and asexual
• no food vacuole - absorb through plasma membrane

Question 11

4. Characteristics of Heterokonts

Answer 11

•Two different flagella

-smooth and hairy

•mostly on eggs and sperm

Question 12

4a. Oomycota (water moulds)

Answer 12

•Fungus- like water moulds, white rusts, downy mildews

• live as saprophytes or parasites
• grow as masses of hyphae
• >Form a network called mycelium
• secrete enzymes to digest organic matter
• sexual and asexual reproduction

Question 13

4b. Bacillariophyta: Diatoms

Answer 13

• Photoautotrophs
• Carbon-fixing marine plankton
• Bilateral and radial
• Asexual and sexual reproduction

Question 14

4c. Chrysophyta: Golden Algae

Answer 14

•Moslty photoautotrophs
•Not enough light -> heterotrophs
•Colonial forms
-Each cell with pair of flagella
•Brown colouring from Fucoxanthin

Question 15

4d. Phaeophyta: Brown Algae

Answer 15

• Photoautotrophs
• multicellular marine forms
• Contain fucoxanthin, algin

•Kelps: Largest, most complex protists

• Differentiated structures:
• Blades
• Stipes
• Holdfasts

•Alternation of generations:
Sporophyte (diplod) and gametophyte (haploid)

Question 16

5. Characteristics of Cercozoa

Answer 16

• Amoebas
• Single-celled
• Move by stiff, filamentous pseudopodia
• Many produce hard outer shells - tests

Question 17

5a. Radiolaria: Radiolarians

Answer 17

• Marine heterotrophs
• Glassy internal skeleton
• Axopods
  
  • Raylike cytoplasmic structures
  • Provide buoyancy
  • Used in feeding

Question 18

5b. Foraminifer: Forams

Answer 18

• Marine heterotrophs
• Cytoplasm extends through perforations in shells
  • traps prey
• Spiral shells containing calcium carbonate
• Some with algal symbiont

Question 19

5c. Chlorarachniophyta

Answer 19

•Autotrophs

• Contain chloroplast -> photosynthetic
• Also heterotrophs

-> filamentous pseudopodia – engulf food

Question 20

6. Characteristics of Amoebozoa

Answer 20

a. Amoebas
- Most amoebas

b. Slime moulds
i. Cellular
ii. Plasmodial
- Complex life cycle
- fruiting bodies forms spores by asexual or sexual reproduction

Question 21

6a. Amoebas

Answer 21

• Most amoebas
• Marine, freshwater, soil
• Heterotrophs
• Some parasitic -> amoebic dysentery
• Unsupported pseudopod
• Asexual -> binary fission
• Single-celled

Question 22

6b. Slime Moulds

Answer 22

Cellular slime moulds

• Single and multicellular
• Fruiting body – holds spores
• Sexual
• Meiosis->haploid
• Fusion->diploid
• Asexual->haploid
• Plasmodal slime moulds
• Plasmodium - Mass of cytoplasm with many nuclei
• Fruiting bodies – hold spores
• nuclei enclose into single cells
• Meiosis ->haploid spores
• Fusion -> diploid zygote

Question 23

7. Characteristics of Archaeplastida

Answer 23

• Includes land plant and two protist groups
• all photoautotrophs

Question 24

7a. Rhodophyta: The Red Algae

Answer 24

• Most small marine seaweeds
• Typically multicellular
• Plant-like bodies
• stalks and leaf-like blades
• cell walls of cellulose and pectin
• Accessory pigments phycobilius
• Alternation of generations but no flagellated gametes

Question 25

7b. Chlorophyta: The Green Algae

Answer 25

• Same pigment as plants
• Symbionts
  • with fungi or animals
• Sexual
• Unicellular ->diploid
• Multicellular ->haploid
• Asexual ->haploid
• Genomes most similar to plants
• Charophytes: Likely algal ancestor of land plants

Question 26

8. Opisthokonts

Answer 26

• Single posterior flagellum
• Group also includes animals and fungi

a. Choanoflagellata (choanoflagellates)

• Collar of microvilli surrounds single flagellum
• Most sessile
• Likely ancestors of fungi and animals