Animals

Question 1

Heterotrophy

Answer 1

• ancestral trait of all animals
• depend on producers for energy
• ingest and digest internally

Question 2

What are the two ancestral characteristics for animals?

Answer 2

eukaryotic and no cell wall

Question 3

what are the four shared derived traits for animals?

Answer 3

A1 - Multicellular
A2 - Extracellular matrix
A3 - Early Embryonic Development Pattern
A4 - Homeobox Genes

Question 4

describe the shared derived trait, extracellular matrix

Answer 4

• proteins are around cell membrane

- connects and supports cells, mostly made of collagen

Question 5

describe differentiated cells in animals

Answer 5

• have specialized functions
• (most have) differentiated tissues = groups of cells with common structure and function
• (many have) differentiated organs = specialized structures made up of tissues

Question 6

describe reproduction and development within animals

Answer 6

• usually sexual
• diploid dominant
• meiosis produces haploid sperm or egg
• fertilization: small flagellated sperm fuses with larger non-motile egg

Question 7

describe the shared derived trait, early embryonic development pattern

Answer 7

• relates development pattern to phylogeny
• cleavage: mitotic divisions without growth
• blastulation: cell migration, forming a hallow ball of cells
• blastula: hallow ball of cells surrounding blastocoel (empty space)
• gastrulation: process of inward folding of blastula
• gastrula and germ layers

Question 8

how is development regulated by genes?

Answer 8

homeobox genes

Question 9

describe the shared derived trait, homeobox genes

Answer 9

• code for proteins that regulate expression of developmental genes
• control expression of many genes
• ex. hox genes

Question 10

symmetry

Answer 10

arrangement of body structure in relation to axis of body

Question 11

asymmetry

Answer 11

no plane of symmetry through body

Question 12

what are the types of symmetry

Answer 12

radial and bilateral symmetry

Question 13

radial symmetry

Answer 13

any plane through longitudinal axis (e.g. mirror images)

Question 14

bilateral symmetry

Answer 14

one plane through longitudinal axis (e.g. mirror images)

• related to cephalization: development of a head with a CNS and sense organs
• facilitates complex movement

Question 15

what are the different bilateral animal axes?

Answer 15

• left/right
• dorsal/ventral
• anterior/posterior

Question 16

germ layers

Answer 16

concentric layers of embryonic tissue

Question 17

ectoderm

Answer 17

outside layer

-outer covering NS

Question 18

endoderm

Answer 18

inner layer

-lines digestive tube, other organs (lungs)

Question 19

mesoderm

Answer 19

middle layer

-everything else

Question 20

diploblasts

Answer 20

only have endoderm and ectoderm

Question 21

triploblasts

Answer 21

have endoderm, mesoderm, and ectoderm

Question 22

do body cavities apply to diploblasts, triploblasts, or both?

Answer 22

triploblasts only

Question 23

coelom

Answer 23

body cavity - fluid filled space between body wall and digestive tube

Question 24

Acoela

Answer 24

no coelom

Question 25

what phyla is a true coelom ancestral to?

Answer 25

5-12, Echinodermata - Arthropoda

Question 26

acoelomate

Answer 26

- flat - filled in coelom - had a coelom, but it doesn't work anymore (ancestral)

Question 27

pseudocoelomate

Answer 27

-use coelom as a hydrostatic skeleton (support, movement)

Question 28

coelomate

Answer 28

- ancestral trait | - true coelom

Question 29

what are the advantages to a coelom?

Answer 29

- hydrostatic skeleton: support, movement - circulation: no longer need to be flat - no cavity? diffusion from outside - SA:V problem

Question 30

what are the two basic modes of animal development?

Answer 30

protostomes and deuterostomes

Question 31

what are the three traits animal development is based on?

Answer 31

- cleavage - coelom formation - fate of blastospore

Question 32

what event happened that allowed the three traits of animal development to appear? explain.

Answer 32

the Cambrian Explosion ~500 - 540 mya -1st appearance of many body plans in fossil record -1st evidence of hard body plans -many extant phyla appear, many others now extincct

Question 33

character

Answer 33

specific unique development pattern

Question 34

give an example of an ancestral character state

Answer 34

protostome

Question 35

describe protostome development

Answer 35

- ancestral mode of animal development - spiral, determinate cleavage - coelom from masses of mesoderm - blastospore -> mouth (protostome = "1st opening")

Question 36

describe deuterostome development

Answer 36

- derived development mode in some animal groups (appeared several times) - radial, indeterminate cleavage - coelom from folds of archentron (ancient intestine) - blastospore -> anus (deuterostome = "2nd opening")

Question 37

what is the sister taxon to animals? describe

Answer 37

choanoflagellates - flagellated, unicellular - extremely similar to choanocytes of sponges (basal animals) - similar cells found in other animals, not other groups

Question 38

is the Metazoa Clade mono-, para-, or polyphyletic?

Answer 38

Monophyletic

Question 39

What does 'Eumetazoa' mean?

Answer 39

true animals

Question 40

What are the shared derived traits of eumetazoa?

Answer 40

- diploblast tissues | - radial symmetry

Question 41

what are the ancestral traits of eumetazoa?

Answer 41

multicellularity, heterotrophy, ECM...

Question 42

what are the shared derived traits of Bilateria?

Answer 42

- triploblast tissues | - bilateral symmetry

Question 43

describe bilateria (excluding the SDTs)

Answer 43

- most animal phyla - almost all share coelomate ancestor - rapid diversification during Cambrian Explosion

Question 44

what are the three major clades within Bilateria?

Answer 44

Deuterostomia, Lophotrochozoa, and Ecdysozoa

Question 45

Deuterostomia

Answer 45

SDT: deuterostome development remember, some with deuterostome development outside this group

Question 46

what is Lophotrochozoa made up of?

Answer 46

entirely invertebrates

Question 47

what is the SDT of Lophotrochozoa?

Answer 47

genetic similiarities (grouped based on DNA)

Question 48

what is the SDT for the Ecdysozoan clade?

Answer 48

ecdysis: molting/shedding exoskeleton/cuticle