Week 2

Question 1

What are protists (protozoa)

Answer 1

Single-celled eukaryotes that are not plants, animals, or fungi (NOT PROKARYOTES)

Question 2

List subcellular specialization in Protozoa

Answer 2

 Excretion (contractile vacuoles)
 Locomotion (cilia, flagella, pseudopodia)
 Digestion (oral groove, lysosomes)
 Reproduction (micronucleus)
 Defense (extrusomes)
 External support (test)
 Internal support (cytoskeleton)

Question 3

Micronucleus function

Answer 3

Comparable to gonad “master copy”

Question 4

Macronucleus function

Answer 4

Working copies, contains millions of copies of certain genes

Question 5

Asexual fission

Answer 5

Transverse – fission plane cuts across kinetids (organism splits)

Question 6

Sexual conjugation

Answer 6

conjugation – involves meiosis and exchange of haploid micronuclei (macronucleus degenerate prior to conjugation) (organisms come together)

Question 7

2 main groups of Euglenozoa

Answer 7

Euglenoidea and Kinetoplastida (both use flagella for movement)

Question 8

Euglenoida characteristics

Answer 8

• autotrophs, heterotrophs (switch between the two)
• chloroplasts, pyrenoids
• pellicle reinforces cell membrane and provides flexibility and contractility
• 2 flagella
• clonal reproduction

Question 9

Kinetoplastida characteristics (+2 diseases)

Answer 9

heterotrophs, mostly parasitic, kinetoplast (large mass of DNA in single mitochondrium), undulating membrane
 Cause 2 diseases: Leishmania and Trypanosoma (Chagas disease or African Sleeping Sickness)

Question 10

Chlorophyta

Answer 10

Green algae - close relative to green plants (example for evolution of multicellularity)

Question 11

Gonidia

Answer 11

Daughter colonies via division of aflagellated cells

Question 12

Choanoflagellata characteristics

Answer 12

• Heterotrophic
• Single flagellum with collar
• Suspension feeders
• Solitary or colonial
• Sister taxon to metazoa

Question 13

Alveolata characteristics

Answer 13

Corticle alveoli (cortical vesicles that support cell membrane)

Question 14

3 taxa of alveolates

Answer 14

Dinoflagellata
Ciliophoran
Apicomplexa

Question 15

Dinoflagellata characteristics

Answer 15

2 flagella, silica test
Red tides+bioluminescence

Question 16

Cingulum

Answer 16

(dinoflagellates)
Transverse groove that also has a flagellum

Question 17

Sulcus

Answer 17

(dinoflagellates)
Longitudinal groove in which one flagellum lies

Question 18

Theca

Answer 18

(dinoflagellates)
Rigid cellulose, often sculpted skeleton, occurs in the alveoli

Question 19

Ciliophora characteristics

Answer 19

multiple cilia, 2 types of nuclei, cristae, carbs stored as glycogen

Question 20

Crista

Answer 20

(ciliophora)
Folds of inner mitochondrial membrane

Question 21

Protist defense structures (5)

Answer 21

(1) Extrusomes
(2) Trichocysts
(3) Toxicysts
(4) Mucocysts
(5) Haptocysts

Question 22

Extrusomes

Answer 22

(protista)
membrane-bound defensive structures

Question 23

Trichocysts

Answer 23

(protista)
Long nail-like spines that are presumably used in defense

Question 24

Toxicysts

Answer 24

(protista)
Discharge a long thread with a toxic bulb at the base - used for defense and for capturing prey

Question 25

Mucocysts

Answer 25

(protista)
Release mucus filaments - used in defense or prey capture

Question 26

Haptocysts

Answer 26

(protista)
Harpoon-like structures used by suctorians for prey capture - similar to nematocysts

Question 27

What species/group causes malaria?

Answer 27

Plasmodium

Question 28

2 types of psuedopodia

Answer 28

Lobopodia and filopodia

Question 29

Actinopoda (characters/grouping)

Answer 29

Characters:
- Axopodia (needle like psuedopodia) used for prey capture, flotation, locomotion, attachment
- mostly organic test (sometimes silica)
Groups: Radiolaria and Heliozoa

Question 30

Porifera characteristics/apomorphies

Answer 30

• Sessile adult with internal aquiferous system (filter feeding through ostia pores)
• Pinacocytes
• Mesohyl
• Archeocytes
• Sclerocytes
• Porocytes
• Stereoblastula

Question 31

Pinacocytes

Answer 31

(porifera)
Pavement-like cells

Question 32

Mesohyl

Answer 32

(porifera)
Connective tissue layer between pinacoderm and the choanoderm

Question 33

Archeocytes

Answer 33

(porifera)
Large, macrophage like cells are progenitor cells in mesohyl

Question 34

Sclerocytes

Answer 34

(porifera)
Secrete the spicules

Question 35

Porocytes

Answer 35

(porifera)
Miniature sphincter valves - single cells - create ostia - several cells - dermal pores

Question 36

Stereoblastula

Answer 36

(porifera)
Solid ball of cells - arises from coeloblastula

Question 37

Describe the water flow of porifera/aquiferous system

Answer 37

Water enters via flagella/cilia movement in ostium -> choanocyte chamber/spongocoel -> exits via osculum

Question 38

Porifera body plans (3)

Answer 38

Asconoid
Synconoid
Leuconoid

Question 39

Hexactinellida apomorphies

Answer 39

• Siliceous spicules
• 6 -rayed
• Syncytium
• Secondary silicification

Question 40

Demospongiae apormorphies

Answer 40

• Siliceous tetraxons
• Spongocytes and spongin

Question 41

Calcarea apomorphies

Answer 41

• Calcium carbonate (calcite) spicules
• Large choanocytes
• Coeloblastula larva

Question 42

Characteristics of metazoa

Answer 42

• motile
• heterotrophic
• mulitcellular
• develop from embryo (embryogenesis)
• somatic differentiation (soma versus germ line)
• specialized tissues (epithelium shells and connective tissue)

Question 43

Embryogenesis (benefits)

Answer 43

Creates cellular diversity
Maintneance of stem cells
Coordination of function

Question 44

Advantages of multicellularity (2 main examples)

Answer 44

1. Division of labour (efficiency X complexity)
2. Increase in size

Question 45

Mechanisms of metazoan origin (2)

Answer 45

Clonal development and aggregation

Question 46

Clonal development

Answer 46

Multicellularity arises by serial cell division without separation of sister cells

Question 47

Aggregation

Answer 47

Separate cells converge and adhere to each other