Chapter 32

Question 1

2 Divisions of animal kingdom

Answer 1

Parazoa
Eumetazoa

Question 2

Kingdom Animalia 9 general characteristics

Answer 2

Heterotrophy
Multicellularity (Complex bodies)
No cell walls
Active movement (more rapid and complex)
Diversity of form (morphology)
Diversity of habitat
Sexual reproduction (Most do)
Embryonic development
Tissues (many cells working together for same function)

Question 3

4 Types of eaters

Answer 3

Herbivore - Plant material
Omnivore - Plant and meat/tissue
Carnivore - Other animals (Meat/tissue)
Detritivore - Dead things

Question 4

Lack of cell walls

Answer 4

Lack rigid cell walls and are flexible. May have extra layer that limits flexibility (Exoskeleton or proteins (collagen)
Extra cellular frame.

Question 5

Embryonic development
Blastula
Gastrula

Answer 5

Starts with sperm and egg and then the zygote is the 1st 2n cell which performs mitosis rapidly.
Blastula - # of cells clustered together. Can fold in on itself to form a hollow sac. Mouth end and anus end. Which ever forms first helps classify the organism.
Gastrula - Blastula with a hollow sac that has formed.

Question 6

Tissues

Answer 6

Cells of most animal are organized into structural and functional units called tissues. Tissues used to maintain homeostasis easier.
6 types. Connective tissue (Blood vessels), nervous tissue, epithelial tissue, skeletal muscle, cardiac muscle, and smooth muscle

Question 7

5 Key innovations in animal evolution

Answer 7

Symmetry
Tissue allowing specialized structures and functions
Body cavity, made possible by 3 germ layers (Endoderm, mesoderm, ectoderm)
Patterns of embryonic development
Segmentation or repeated body units.

Question 8

Symmetry

Answer 8

Most animals have radial or bilateral symmetry. (Sponges exception)
Radial symmetry (Pie/pizza) - Body parts arranged around central axis. Divided into two equal halves by any plane that passes through the center
Bilateral symmetry (humans, dogs) - Body has right and left halves that are mirror images. Only sagittal plane bisects the animal into two equal halves. Advantages over radial 1 Directional movement, Cephalization (evolution of a definite brain area)

Question 9

Bilateral symmetry advantages

Answer 9

1 Directional movement
2 Cephalization - evolution of a definite brain area

Question 10

Evolution of tissues allowed for specialized structures and funtions

Answer 10

Zygotes (fertilized eggs) are totipotent (Potential to form any cell type in body)
Cells specialized during embryo development, process irreversible (except sponges). All animals have distinct and well-defined tissues

Question 11

Germ layers

Answer 11

Most have 3 germ layers- triploblastic
Ectoderm (body coverings and nervous system)
Mesoderm (skeleton and muscles)
Endoderm (digestive organs and intestines)
Triploblasts have bilateral symmetry.
Cnidarians are diploblastic, only endo and ectoderm.
Sponges lack germ layers

Question 12

Body cavities

Answer 12

Acoelomates = no body cavity
Pseudocoelomates = body cavity between mesoderm and endoderm
Coelomates = Body cavity entirely within the mesoderm all deuterostomes have coeloms.
Use to be morph based phylogeny
Protostomes are variable

Question 13

Circulatory systems

Answer 13

Coelomates developed a circulatory system that flows nutrients and removes wastes.
Open circulatory system - blood or similar fluid passes from vessels into sinuses, mixes with body fluids and reenters the vessels. Blood gets back to heart without vessels
Closed circulatory system - blood moves continuously through vessels that are separated from body fluids.

Question 14

Two different patterns of development for bilaterians

Answer 14

Basic pattern of development - Mitotic cell divisions (cleavages) form a hollow ball of cells called the blastula. Blastula indents to form a two-layer-thick ball with blastopore (opening to outside) and archenteron (primitive body cavity)

Question 15

Groups of bilaterians

Answer 15

Protostomes - Develop mouth first from or near blastopore. Anus develops either from blastopore or another region of embryo if present. (arthropods, mollusks)
Deuterostomes - Develops the anus first from the blastopore. Mouth develops later from another region of the embryo. (Vertebrates)

Question 16

Segmentation 2 advantages

Answer 16

1 Allows for redundant organ systems in adults such as occurs in the annelids (earthworms)
2 Allows for more efficient and flexible movement because each segment can move independently.
Segmentation appeared several times in evolution of animals.
Worms, lobsters, fish and humans (backbone and muscles.)

Question 17

Animal phylogeny

Answer 17

Traditional looked at body plan, morph, life cycle
New are molecular data.

Question 18

Classification of animals

Answer 18

Multicellular animals are divided into distinct phyla. Animals are divided into two main branches
Parazoa - Sponges monophyletic
Eumetazoa = all other animals.

Eukarya -> Opsithoknotas -> Parazoa and Eumentazoa

Question 19

Protostome division

Answer 19

Lophotrochozoans - Grow by gradual addition to the body mass. Have spiral cleavage
Ecdysozoans - Animals that molt. Includes arthropods and other phyla

Question 20

Deuterostome division

Answer 20

Includes chordates and echinoderms (starfish).
Consists of fewer phyla and spp than protostomes. More uniform in many ways

Question 21

Kingdom Animalia

Answer 21

Metazoa
divided into 2 branches
Parazoa - animals lacking tissues and definite symmetry
Eumetazoa - animals with a definite shape, symmetry, tissues and possibly organs

Question 22

Phylum Parazoa

Answer 22

Sponges. 26,000 marine and 150 freshwater.
Among the most abundant animals in deep ocean.
Sexual and asexual, fragmentation. Coenocytes- flagellated sperm cells with collar and swim to egg to develop in mother or fertilized egg released and floats to new spot

Question 23

Porifera characteristics

Answer 23

Sponges, lack symmetry. Various growth forms. Larval sponges free swimming. Adults attached and sessile. Cell types, truly multicellular. 3 functional layers in vase shaped body

Question 24

3 layers of body wall of Porifera

Answer 24

1Outer epithelium - flattened cells with lots of pores for water movement through flagellated layers. Ostia comes in, osculum exits
2Mesohyl - middle, gelatinous matrix. Spicules needles of (calcium carbonate), Spongin (reinforcing tough protein fibers) both of skeleton.
3Lining of internal cavity. Choanocytes. Collared cells, flagellated to contribute to water circulation. Face of internal cavity. Engulf and digest food from passing water.

Question 25

Eumetazoa charecteristics

Answer 25

Animals with true tissues. Embryos have distinct germ layer
Endoderm forms gastrodermis (digestive tissue)
Ectoderm forms the epidermis and nervous system
Mesoderm (only in bilaterals) forms the muscles.
True body symmetry
Triploblasts
Diploblasts have endo and ectoderm layers

Question 26

Phylum Ctenophora

Answer 26

Comb jellies, sea walnuts, or sea gooseberries
8 rows of comb like plates of fused cilia that beat in a coordinated fashion. Many bioluminescent, transparent, few cm long.
2 tentacles covered with colloblasts (discharge strong adhesive used to capture prey). Phylogenetic position unclear

Question 27

Phylum Cnidaria

Answer 27

Hydroids, jellyfish, sea anemones, corals. Most marine, few freshwater spp. Diploblastic. Bodies have distinct tissues but no organs. No brain, reproductive, circulatory, digestive, or excretory systems. Capable to do all just no organ system. Latticework of nerve cells, touch, gravity, light receptors. Capture prey with nematocysts (Capsules secreted within nematocyte, discharge to capture, digest, or defend. Some carry venom).

Question 28

Cnidarian life cycle

Answer 28

Two body pans medusa, adult, polyp young cup shaped on stalk. Most alternate phases. Diploid individuals in both phases. Medusa forms gametes. Gonochorism. Zygote develops into planktonic planula, metamorphosis into polyp, produces medusae or other polyps asexually.

Question 29

Cnidarians digestion

Answer 29

Major evolutionary innovations in cnidarians is extracellular digestion of food inside the animal. Digestion takes place partly in gastrovascular cavity, digestive enzymes released and broken into smaller pieces. Phagocytosis by cells to engulf fragments.

Question 30

Classes of Cnidarian

Answer 30

Anthozoa- sea anemones, most corals, sea fans
Cubozoa - box jellies
Hydrozoa - hydroids, hydra, Portuguese man of war
Scyphozoa - jellyfish
Staurozoa - star jellies

Question 31

Bilaterian acoelomates

Answer 31

Characterized by bilateral symmetry, allowed for high level specialization. 2 Clades, protostomes, deuterostomes.
Acoel flatworms are transitional between proto and deutero

Question 32

Phylum Acoelomorpha (Acoela)

Answer 32

Acoel flatworms. Have a primitive nervous system and lack a digestive cavity. Similarities are convergent.