Gilmour - Eukaryotic Microbial Diversity

Question 1

Do Eukarya show greatest diversity in metabolism or size and shape?

Answer 1

size and shape, they have less diversity in metabolism

Question 2

name the 3 high level divisions within Eukarya

Answer 2

fungi and animals
primary endosymbiotic algae and plants
protists

Question 3

describe the morphology and give 2 organisms found in the opisthokonta group

Answer 3

have backward pointing flagellum (eg spermatozoa and zoospores)
animals/fungi/microsporidia/choanoflagellates

Question 4

what is reduction/degenerative evolution and give an example

Answer 4

the loss of structures in complex organisms eg the loss of flagellum in some fungi

Question 5

describe the link between choanoflagellates and choanocytes and why its significant

Answer 5

choanoflagellates are unicellular and resemble choanocytes, however choanocytes are found in sponges - link between microbial and multicellular eukaryotes

Question 6

which organisms have moved in and out of the opisthokonta group?

Answer 6

IN: microsporidians (protists) because highly conserved peptide seq only found in animals and fungi
OUT: slime moulds (from fungi to protists)

Question 7

define primary endosymbiotic bacteria

Answer 7

early eukaryotic cells with mitochondria - used cyanobacteria as foodstock leading to the creation of the chloroplast (this is indicated by the presence of the double membrane)

Question 8

name the 2 types of primary endosymbiotic algae we studied

Answer 8

chlorophyta (green algae)

rhodophyta (red algae)

Question 9

name 2 green alga and compare their morphology and genetics

Answer 9

Chlamydomonas reinhardti
- unicellular/ 2 anterior flagella/genetics well understood, uses mating types
Dunaliella
- unicellular/halotolerant/no cell wall/genetics not well understood

Question 10

describe the morphology of rhodophyta and their uses

Answer 10

many multicellular, some unicellular/filamentous
often found in association with seaweeds
red pigment from phycoerythrin
used in food - nori/laverbread

Question 11

which 2 groups once made up the protists and what does this signify?

Answer 11

was algae and protozoa - shows how genetics have led to major reclassifications in phylogeny

Question 12

which 2 major traits seprate primary and secondary endosymbiotes?

Answer 12

1) more than 2 membranes around secondary endosymbiotic chloroplast
2) mixotrophy/heterotrophy widespread in secondary endosymbiotes

Question 13

which noticeable feature of secondary endosymbiotes make them different from primary endosymbiotes

Answer 13

often have major and minor nuclei

Question 14

describe the morphology of diatoms and name the group they belong to

Answer 14

can be pennate (look like stretched lemon) or centric (look like petri dish) diatoms
responsible for approx 20% world photosynthesis
have silica cell walls
asexual reproduction results in decreasing size, this is reversed in sexual repro
are secondary endosymbiotes

Question 15

describe the morphology of brown algae and name the group it belongs to

Answer 15

can get up to 70m (kelp)
fucus is type of seaweed
posses vacuoles of leucosin used for energy storage
no xylem/transport systems therefore not plants
are secondary endosymbiotes

Question 16

describe the morphology of a group of the haptophytes, name a species and explain its importance

Answer 16

coccolithophores eg Emiliania huxleyi
CaCO3 exo skeleton of coccoliths (=protection)
forms 1000km blooms - important C source when they die and sink to sea floor

Question 17

describe the morphology, grouping and importance of the Dinoflagellates

Answer 17

2 different flagella - transverse and longitudinal - spinning swimming motion
are grouped as alveolates (have alveoli)
several species are toxic (eg Gonyaulax) which forms red tides (leads to bioaccumulation in species)

Question 18

describe the morphology and grouping of the alveolates and give an example of one

Answer 18

contain alveoli beneath outer membrane (includes the ciliates eg Paramecium)
contains 2 nuclei (1 diploid - generates macronucleus with many DNA copies & micronucleus for sexual repro)
Apicomplexans - contain apicoplast (derived from endosymbiotic chloroplast) used for entry into host eg Plasmodium falciparum

Question 19

briefly describe the morphology, sexual life cycle and name a species of slime mould

Answer 19

move using pseudopodia - based on actin polymerisation
amoeba aggregate into large fruiting bodies (cAMP is aggregating molecule)
Dictyostelium is a cellular slime mould - the
individual cells remain cellular.

Question 20

give 2 examples of a type of Discoba and their metabolic activities

Answer 20

Euglena is a secondary endosymbiote which can lose flagella and grow heterotrophically/ v acid tolerant
Trypanosomes not secondary endosymbiotes and cause major diseases eg African Sleeping Sickness

Question 21

Metamonada are protists that have lost their ______ via degenerative evolution, name a species

Answer 21

mitochondria

eg Giardia lamblia