Lecture 12

Question 1

when was luca

Answer 1

3.6 billion years ago

Question 2

how long ago did eukaryogenesis take place

Answer 2

2 billion years ago

Question 3

draw a tree with bacteria archaea eukaryotes and LUCA

Answer 3

luca diverges into bacteria and archaea, archaea splits into eukaryotes 2 billion years ago

Question 4

now draw the tree as a ring

Answer 4

luca into archaea and bacteria into eukaryotes

Question 5

what is eukaryogenesis

Answer 5

the eubacterium ends up inside an archaebacterium

an archaebacterium consumed a heterotrophic eubacterium

Question 6

the trapped eubacterium becoming a mitochondrion gave ____ which enabled….

Answer 6

energy which enabled eukaryotic cells to grow significantly bigger

Question 7

features of eukaryotes

Answer 7

membrane bound organelles
nucleus
mitochondria 
phagocytosis
meiosis
large genomes

Question 8

all multicellular organisms are

Answer 8

multicellular

Question 9

are eukaryotes multicellular or unicellular

Answer 9

both (all eukaryotes were unicellular 1 billion years ago)

Question 10

what the four major lineages to multicellular eukaryotes

Answer 10

animals plants fungi red algae

Question 11

what is an animal

Answer 11

multicellular eukaryote
no cell wall 
motile (at least at some stage) 
heterotrophic 
blastula in development

Question 12

how many times did multicellularity evolve

Answer 12

25 times in four different lineages

Question 13

bilaterian are divided into which two groups

Answer 13

protostomes and deuterostomes

Question 14

draw the modern bilateral tree

Answer 14

ancestrial bilaterian breaking into deuterostomia and the branch for protostomia which is split into two, lophotrochozoa and ecdysozoa

Question 15

examples of deuterostomia

Answer 15

chordates echinoderms and relatives

Question 16

examples of lophotrophochozoa

Answer 16

annelids molluscs and relatives

Question 17

examples of ecdysozoa

Answer 17

arthropods, nematodes and relatives

Question 18

what group are moulting animals

Answer 18

ecdysozoa

Question 19

describe the lophotrochozoan grouping

Answer 19

loose grouping, mostly with spiral cleavage and trophophore larvae (sometimes further divided into lophotrochozoan and spralia)

Question 20

what is the most diverse eukaryotic group

Answer 20

insects

Question 21

describe eocyathispongia qiania

Answer 21

3 openings loads of pores in body wall

Question 22

what are choanocytes

Answer 22

specialised flagella on collar cells (found on sponges)

Question 23

how do sponges eat

Answer 23

intracellular digestion (phagocytosis) through collar

Question 24

when does ephydatia muelleri sneeze

Answer 24

when inedible ink is poured on it/works with agitation

Question 25

what releases the sneezing behaviour

Answer 25

application of glutamate releases behaviour, GABA and nitric oxide is also involved

Question 26

reorganisation of sponges (4)

Answer 26

sponges can reconstitute themselves
break up sponge into cells
allows it to sit ends up reforming
odd behaviour for an animal, but based on recognition of self

Question 27

what is a choanoflagellate

Answer 27

very similar to sponge choanocyte

shows social behaviour by cells, this could be the origin of sponges and of animals

Question 28

dictyostelium (3)

Answer 28

social amoeba- slime mould
solitary and social phases
slug, stalk, mound

Question 29

what releases cAMP

Answer 29

starving cell releases cAMP
then cAMP relay during aggregation
unrelated cells join together

Question 30

cAMP to ______ order

Answer 30

mound to slug or to stalk and fruiting body

Question 31

structure of choanoflagellate

Answer 31

stalk, single cell, flagellum