Protist and Fungi diversity

Question 1

What are protists?

Answer 1

Structurally and functionally diverse group of eukaryotes that span all four supergroups (excavata, Unikonta, SAR, Archaeplastida)

Question 2

What are the defining qualities of supergroup excavata?

Answer 2

1. Some members of supergroup have an excavated feeding groove on the side of the cell body.
2. Corkscrew flagella
3. Free-living (autotrophic) and parasitic (trypanosomes) species

Question 3

What is mixotrophy?

Answer 3

Primarily autotrophic, but heterotropic with limited access to light.

Question 4

What is Euglenozoa?

Answer 4

Type of freeliving/parasitic phylum in supergroup Excavata that are mixotrophic.

Question 5

What are euglenids?

Answer 5

Lineage of phylum euglenozoa that are unicellular, freshwater, mixotrophic organisms with a contractile vacuole, membrane bound nucleus and one or two polar flagella.

Question 6

What is the SAR clade?

Answer 6

Highly diverse group of protists defined by DNA similarities and consists of stramenopiles (diatoms, brown and golden algae), alveolates (dinoflgellates), and rhizarians.

Question 7

What are diatoms and what do they look like? What do they do?

Answer 7

Unicellular stramenopile algae with a two-part glass like wall of silicon dioxide. Major component of phytoplankton and are found in the ocean and lakes.

Question 8

What is diatomaceous earth made of?

Answer 8

Sediments of fossilized diatom walls.

Question 9

What’s the difference between brown and golden algae?

Answer 9

Golden Algae: stramenopile with yellow and brown carotenoids (pigments) with a simple structure, mostly in groups of unicellular organisms

Brown Algae: stramenopile with large complex multicellular structures (e.g. kelp, giant seaweed)

Question 10

What are the plant-like structures of an algae?

Answer 10

Holdfast: anchors algae
Blades: leaf-like structures that perform photosynthesis
Stipe: supports leaflike blades and brings it closer to the sun

Question 11

Are the generations of the algae life cycle heteromorphic, or isomorphic?

Answer 11

Heteromorphic

Question 12

What is the life cycle of brown alga?

Answer 12

1. diploid sporophtye produces haploid via meiosis spores in the diploid sporangia
2. haploid zoospores mature into haploid female and male haploid gametophytes via mitosis
3. mature haploid sperm is produced from haploid male gametophyte which is released to fertilize a haploid egg in a haploid female gametophyte to form a diploid zygote
4. Diploid zygote undergoes mitosis to develop into a diploid sporophyte

Question 13

What are Dinoflagellates?

Answer 13

A group of flagellated alveolates made of cellulose that are a major component of phytoplankton. Explosive growth results in mass production of toxins that kills many invertebrates and fishes.

Question 14

What is the archaeplastida? What are the types?

Answer 14

A diverse photosynthetic protist supergroup that includes red and green algae found in diverse habitats. Can be unicellular (chlamydomonas), grouped (Volvox), multicellular (Ulva, Caulerpa)

Question 15

What is red algae?

Answer 15

Type of non-flagellate archaeplastida that are red due to pigment phycoerythrin and are mostly multicellular.

Question 16

What are the three main components of algal cell structure?

Answer 16

1. Cell wall: made of cellulose, some carbohydrates, and proteins (for transport); rigid when mature but permeable to water, gases, minerals.
2. Vacuole: regulate water content to maintain turgor pressure
3. Pyrenoids: Site of starch synthesis within chloroplasts

Question 17

What is the life cycle of green algae?

Answer 17

Sexual: Mature haploid cells develop into gametes due to nitrogen stress and fertilize into a diploid zygote, which bursts releasing haploid spores

Asexual: Mature haploid cell grows via mitosis and releases individual zoospores which mature into mature cells

Question 18

What is the difference between heterogamy and isogamy?

Answer 18

Heterogamy: gametes are morphologically different (brown algae)

Isogamy: gametes are morphologically identical

Question 19

Where did fungi originate?

Answer 19

aquatic, single-celled flagellated protist

Question 20

How do fungi obtain nutrients?

Answer 20

Saprophytic heterotroph, parasitic heterotroph, mutualistic heterotroph

Question 21

What is mycelia?

Answer 21

Network of branched hyphae that maximize surface area for absorption

Question 22

What is the difference between septate hyphae and coencytic hyphae?

Answer 22

Septate: divided into cells by septa and have pores for movement of organelles

Coenocytic: lack septa and have a continuous cytoplasmic mass with many nuclei

Question 23

How do fungi reproduce?

Answer 23

Sexual reproduction, or asexual reproduction (moulds and yeasts)

Question 24

what is ascomycetes?

Answer 24

Diverse group of fungi that live in marine, freshwater and terrestrial habitats. Can reproduce sexually via spores in asci in ascocarp fruiting body, or asexually via conidia.

Question 25

What is basidiomycetes?

Answer 25

Group of fungi that include mushrooms, mycorrhize and plant paraistes that have sexual spores in basidium within basidiocarp fruiting body.

Question 26

What is the difference between basidiomycetes and ascomycetes spores?

Answer 26

basidiomycetes: externally produced

ascomycetes: internally produced

Question 27

What roles do fungi play in the ecosystem?

Answer 27

• decomposer of organic material including cellulose and lignin
• mutualist (mychorrhizae, lichen)
• pathogen
• recycle chemical elements between abiotic environment and biotic environment

Question 28

What roles do fungi play in human life?

Answer 28

They are edible (cheese, alcohol, bread) and have medicinal properties (produce antibiotics)