Chapter 33

Question 1

Characteristics of animals

Answer 1

multicellular heterotrophs
unique cell structure

Question 2

Animal cell structure:

Answer 2

No cell wall (has cell membrane)
Extracellular matrix (structural support)
Cell junction (holds cell in place)

Question 3

Modes of nutrition

Answer 3

Suspension feeding
Bulk feeding
Fluid feeding

Question 4

True or false:
Muscle tissue is unique to animals

Answer 4

True

Question 5

Sessile species such as barnacles have..

Answer 5

moving appendages or a swimming larval stage

Question 6

Metamorphosis

Answer 6

Developmental phenomenon in which animal changes from Ta juvenile to an adult form

Question 7

The first animals were

Answer 7

Invertebrates

Question 8

A sudden increase in animal diversity occurred during

Answer 8

the Cambrian explosion (533 - 525 million years ago)

Question 9

3 possible explanations for the Cambrian explosion

Answer 9

Favorable environment
Development of the Hox gene
An evolutionary “arms race”

Question 10

The first vertebrates

Answer 10

Fish (arose approximately 520 million years ago)

Question 11

True or False
Animal kingdom is Monophyletic

Answer 11

True

Question 12

How many recognized animal phyla?

Answer 12

35

Question 13

What is the closest living relative of animals?

Answer 13

Choanoflagellates

Question 14

Choanoflagellates:

Answer 14

Single celled protists
(they bear a striking similarity to sponge choanocytes)

Some are colonial.
Some cells may have taken on spacialized functions.

Question 15

Morphological and developmental features traditionally used to classify animals

Answer 15

Body symmetry
number of germ layers
embryonic development

Question 16

Metazoa

Answer 16

all animals
(multicellular animals)

Question 17

Protozoa

Answer 17

unicellular

Question 18

How is metazoa divided?

Answer 18

Divided based on whether they have specialized tissues.
Parazoa
Eumetazoa

Question 19

Parazoa

Answer 19

without specialized tissue or organs
(ex: Poriferas - Sponges)
may have distinct cell types

Question 20

Eumetazoa

Answer 20

more than one type of tissue and organ
(divided by symmetry)

Question 21

Radiata

Answer 21

Radially symmetric
2 germ layers
(Examples: Cnadaria and Echinoderms)

Question 22

Cnidarians examples

Answer 22

Jelly fish
sea anemones
Corals

Question 23

Echinoderms examples

Answer 23

Sea urchins
brittle stars
sea stars

Question 24

Bilteria

Answer 24

Bilaterally symmetrical
3 germ layers (triploblastic)
Have cephalization and dorsal and ventral sides.
Have anterior and posterior ends.

Question 25

Cell layers develop during

Answer 25

gastrulation

Question 26

Ctenophores

Answer 26

Comb jelly

Question 27

Cell inner layer

Answer 27

Endoderm

Question 28

Cell outer layer

Answer 28

ectoderm

Question 29

Mesoderm

Answer 29

3rd layer in bilateral animals forms muscles and other organs

Question 30

Sponges only have a single germ layer (true or false)

Answer 30

true

Question 31

Protostome

Answer 31

Blastopore becomes mouth Cleavage is determinate (spiral cleavage) Examples: Arthropods mollusks annelid worms

Question 32

Deuterostome

Answer 32

Blastopore becomes anus Cleavage is indeterminate (radial cleavage)

Question 33

Coelom

Answer 33

Fluid filled body cavity

Question 34

Coelomate

Answer 34

true coelom Coelom completely lined with mesoderm (Mollusks, Annelids, earthworms)

Question 35

Pseudocoelomate

Answer 35

Coelom partially lined with mesoderm (rotifiers and round worms)

Question 36

Acoelomate

Answer 36

lacks body cavity (instead has mesenchyme) (flatworms)

Question 37

Functions of the coelom

Answer 37

Cushions internal organs Functions as hydrostatic skeleton Enables movement and growth of internal organs independent of the body wall. Fluid acts as simple circulatory system

Question 38

Body may be divided into regions called

Answer 38

Segements

Question 39

Segemantation occurs in

Answer 39

annelid worms arthropods chordates

Question 40

molecular techniques to classify animals

Answer 40

Compare similarities in DNA, RNA, and amino acid sequences. (Closely related organisms have fewer differences than those more distantly related.)

Question 41

the gene for small subunit ribosomal RNA

Answer 41

SSU rRNA

Question 42

the gene for small subunit ribosomal RNA (SSU rRNA) is:

Answer 42

Universal in all organisms Changes slowly over time

Question 43

Studies regarding Hox genes show

Answer 43

Hox genes are found in all animals. Duplications in these genes may have led to evolution of complex body forms.

Question 44

Ecdysozoa

Answer 44

Nematodes, Arthropods, and a few other minor phyla - Named for ecdysis (molting) - Members secrete an exoskeleton that must be shed and regrown as the animal increases in size

Question 45

Lophotrochozoa

Answer 45

Mollusks, Annelids, and several other phyla * Named for the lophophore (feeding tentacles) and trochophore larva * Some members have neither of these features (for example platyhelminthes), so classified strictly based on molecular data.