Ch. 32 Part 1: Animal Body Plans

Question 1

In Complex Multicellular Organisms, bulk flow

Answer 1

circumvents the limitations of diffusion

Question 2

Complex multicellularity depends on

Answer 2

cell adhesion, communication, and a genetic program for development

Question 3

Animals

Answer 3

• Multicellular
• Heterotrophic eukaryotes with tissues that develop from embryonic layers
• can be characterized by “body plans”

Question 4

Views of animal phylogeny

Answer 4

continue to be shaped by new molecular and morphological data

Question 5

3 types of body cavities

Answer 5

1) Coelomate
2) Pseudocoelomate
3) Acoelomate

Question 6

Pseudocoelomate

Answer 6

exists between the endoderm and mesoderm

false

Question 7

Acoelomate

Answer 7

no body cavity

Question 8

Coelomate

(eu)coelomate

Answer 8

within mesoderm only

true

Question 9

Unicellular

Answer 9

• cell is autonomous
• can do all functions by themselves
• all prokaryotes, many eukaryotes

Question 10

Simple Multicellularity

Colonial

Answer 10

• • Cell adhesion molecules maintain structural integrity (Cadherins)
• Little intercellular communication or nutrient transfer
• Very little differentiation; cells retain most/all functions
• Nearly all cells in direct contact with external environment
• Little cost to losing a cell
• Common in algae

Question 11

Advantages to colonial vs. unicellular

Answer 11

1) Avoid being eaten: size can be a deterrent
2) Maintain position in water column
3) Flagellar currents and filter feeding (suspension)

Question 12

Disadvantages to colonial vs. unicellular

Answer 12

Cells no longer act in a corporative manner

-susceptible to “cancer”

Question 13

Complex Multicellularity

Answer 13

• Highly developed adhesion mechanisms
• Specialized structures for intercellular communication
• Complex patterns of tissue and organ development guided by regulatory gene networks
• 3- dimensional organization
• plants, fungi, animals

Question 14

Complex Multicellularity features

Answer 14

1) Adhesion
2) Communication
3) Development
4) Key innovation in multicellularity

Question 15

Adhesion types

Answer 15

a) cadherins: cell = cell
b) integoins: cell = extracellular matrix (ECM) (critical in animals - no walls)
c) ECM
d) pectins
e) gap junctions: animal: physical connection and intracellular communication (tubes)
f) plasmodesmata: plant: physical connection and intracellular communication (tubes)

Question 16

Communication types

Answer 16

a) gap junctions
b) plasmodes
c) integral (plasma membrane) receptors
d) intracellular receptors

Question 17

Development

Answer 17

molecular signals direct differential gene expression leads to cellular => tissue => organ differentiation

a) division of labor because of
b) different environments

Question 18

Key innovation in multicellularity

Answer 18

ability to enable cells to differentiate in Space instead of Time

Question 19

Biological Design Principles

Answer 19

2nd law of Thermodynamics

diffusion

Question 20

2nd Law of Thermodynamics

Answer 20

• disorder is spontaneous in our Universe
• i.e. high concentration to low concentration
• disorder to order is not spontaneous, but can occur if work is done (input of energy)

Question 21

Diffusion

Answer 21

particles spontaneously move from areas of high concentration to low concentration

has to go through the diffusion path: O2 => membrane (SA) => Cytosol (V) => mitochondria

Question 22

Size limits on cells

Answer 22

SA = 4 * pi * r^2
V = (4/3) * pi * r^3
radius is the only thing varied

SA/V ratio decreases as radius increases

Question 23

Fiele’s Law

Answer 23

Js = DA (∆c/∆x) => linear Js vs [C]

Js = diffusion rate of s (flux)
D = diffusion coefficient (empirically determined) solubility (how fast)
A = surface area
∆c = concentration gradient
∆x = path length

Question 24

Field’s Law and diffusion

Answer 24

increase in D, A, or ∆c will increase Js

decrease in ∆x will increase Js

Question 25

Multicellularity and size of organisms

Answer 25

1) Multicellularity (complex)
2) Size
3) Animal Body Design
4) Body Cavities
5)

Question 26

Multicellularity (complex)

Answer 26

• exterior > interior
• exterior < interior
  (i. e. O2 > ; < CO2)
• nutrients/waste
• temperature, pH, light physical force gradients
• shape

Question 27

Size

Answer 27

If small, then diffusion can work

If larger, then diffusion is insufficient (limiting); therefore, resorts to bulk flow

Question 28

Bulk Flow

Answer 28

a means by which molecules move through organisms at rates beyond those possible by diffusion alone across a concentration gradient (moving faster)

Question 29

3 types of Animal Body Designs (trends)

Answer 29

1) Symmetry
2) Body Cavities
3) Germ layers

Question 30

3 types of Symmetry

Answer 30

1) Asymmetric
2) Radial
3) Bilateral

Question 31

Asymmetric

Answer 31

no mirror image when cut

i.e. sponge

Question 32

Radial Symmetry

Answer 32

• mirror image
• many possible planes
• i.e. circular
• probably started here

Question 33

Bilateral Symmetry

Answer 33

• mid-sagittal plane (left and right)
• mirror image
• one possible plane
• i.e. humans

Question 34

(frontal) coronal plane

Answer 34

dorsal/ventral

Question 35

Traverse plane

Answer 35

anterior/posterior

Question 36

Germ Layers

Answer 36

embryonic tissues (1st ones)
diploblastic vs. triploblastic

Question 37

Diplobastic

Answer 37

2 germ layers:

1) endoderm
2) ectoderm

Question 38

Triploblastic

Answer 38

3 germ layers:

1) endoderm
2) mesoderm
3) ectoderm

Question 39

If triploblastic, then

Answer 39

protostome vs deuterostome

Question 40

Protostome

Answer 40

• Blastopore first opening: mouth
• Spiral cleavage
• Schizocoely = split mesoderm

Question 41

Deuterostome

Answer 41

• Blastopore first opening: anus
• Blastopore seconde opening: mouth
• Radial cleavage
• Enterocoely = grows out of the mesoderm