becoming multicellular

Question 1

how many clades of the 1119 major euk ones are simple multicellularity

Answer 1

30

83 single celled

Question 2

what do simple multicellular orgs look like?

Answer 2

• filaments
• hollow balls
• sheets

Question 3

6 simple multicellular orgs evolved coenocytic organization. define

Answer 3

• nuclei divide multiple times but cells are not partitioned

- mitosis w/our cytokinesis

Question 4

properties of simple multic. (3)

Answer 4

1. adhesion molecs stick adjacent cells together
2. most cells retain full range of function incl repro
3. every cell is in contact w the env

Question 5

how many times did complex multicellularity evolve?

Answer 5

at least 6

Question 6

characteristics of complex multic. (7)

Answer 6

1. highly developed adhesion
2. cell-to-cell communication
3. tissue/organ differentiation
4. only some cells do repro
5. cell/tissue loss can be lethal
6. interior and exterior cells
7. specialized growth and development (gene regulation)

Question 7

diffusion

Answer 7

movement of molecs from areas of high [] to low []

Question 8

bulk transport

Answer 8

by which molecs move through orgs @ rates faster than those possible by diffusion

Question 9

what transmembrane pro’s facilitate adhesion in animals?

Answer 9

cadherins and integrins

Question 10

gap junctions

Answer 10

pro channels that allow xchange of ions and signaling molecs

Question 11

plasmodesmata

Answer 11

allow xchange of ions and signaling momlecs

Question 12

blastula

Answer 12

fert eggs that have undergone repeated mitosis