Chapter 16: Evolution of Animals

Question 1

proper reasons for the Cambrian explosion?

Answer 1

complex predator-prey relationships

Another hypothesis focuses on the evolution of genes

Question 2

four key points in animal evolution?

Answer 2

1) Multicellularity (true tissue) :: sponge vs other (have true tissue)
2) Bilateral symmetry (radial or bilateral symmetry)
3) Body cavities
4) True coelom (coelom from cell mass, coelom from digestive tube)

Question 3

difference between a pseudocoelom and a true coelom?

Answer 3

Pseudocoelom’s body cavity is not completely lined with the peritoneum(tissue) derived by mesoderm, middle layer
True coelom’s is completely lined by tissue derived from mesoderm

Question 4

structural of Porifera Phylum

Answer 4

• Sponges
• Sessile animals, the simplest animals, range in height from about 1cm to 2 meters.
• Sponges have no nerves or muscles, but the individual cells can sense and react to changes in the environment
• Lack real tissues and have amoebocyte (skeleton)

Question 5

structural of Cnidarian Phylum?

Answer 5

• Radial symmetry and having tentacles with stinging cells.

* Jellies, sea anemones, hydras and coral animals

Question 6

structural features and representatives of Platyhelminthes Phylum?

Answer 6

• Simplest bilateral animals, leaflike or ribbonlike, 1 mm to 20 meters in length.
• Planarians are nonparasitic flatworms
-tapeworms, flukes

Question 7

structural features and representatives of Nematoda Phylum?

Answer 7

• Cylindrical bodies
• Have complete digestive tract
• Body cavity (pseudocoelom)

Question 8

the structural features of Mollusca Phylum?

Answer 8

• Soft-bodied animals, mostly protected by a hard shell
• 3 part body plan: a muscular foot, visceral mass, and mantle-fold of tissue (wraps the visceral mass & secretes the shell)

Question 9

three classes and representatives of Mollusca Phylum?

Answer 9

gastropod (snail and slugs)
bivalves (clams and oysters)
and cephalopod (squids and octopuses),

Question 10

structural features of Annelida Phylum?

Answer 10

• The body is divided into a series of repeated parts (body segmentation)The coelom is partitioned by walls. It has segmental blood vessels.
• Less than 1 mm to 3 m in length

Question 11

the three classes and representatives of Annelida Phylum?

Answer 11

earthworms, polychaetes, leeches

Question 12

structural features of Arthropods Phylum?

Answer 12

• Segmented animals, with variety of function ex walk feed sense recep
• Has exoskeleton — constructed from layers of protein and chitin (a polysaccharide)
• Undergo molting (shed old exoskeleton, secrete larger one)

Question 13

four classes and representatives of Arthropods Phylum?

Answer 13

• Arachnids (scorpion, spiders, ticks, mites) – 4 pairs legs & feeding appendages
• Crustaceans (crabs, lobsters, crayfish, shrimps)
• Millipedes (eat decay plant matter) and centipedes (terrestrial carnivores)
• Insects

Question 14

structural features and representatives of Echinoderms Phylum?

Answer 14

Spiny surface, sessile-moving, lack body segment; Have an endoskeleton beneath the skin; have water vascular system,
Sea star,sea urchin

Question 15

common four key features of Chordata Phylum?

Answer 15

①, hollow nerve cord
②notochord, a flexible, longitudinal rod, located between the digestive tract and the nerve cord
③pharyngeal slits
④post-anal tail, a tail to the rear of the anus

Question 16

Besides vertebrate, what are the other two subphyla and representatives of Chordata Phylum?

Answer 16

Tunicates and Lancelets

Question 17

What is the earliest vertebrate? When did it appear the first time on earth? What are its special structural features?

Answer 17

Agnathans, evolved during early Cambrian period, about 540 million years ago
Lacked jaws, paratistes use jawless mouth as suckers to attach large fishes and draw blood

Question 18

A shark belongs to Cartilaginous fishes or Bony fishes?

Answer 18

• Cartilaginous fishes

Question 19

What kind of fish has the closest genetic relationship with amphibian?

Answer 19

• Lobe-finned fishes

Question 20

special adaptations of Reptiles to terrestrial environment?

Answer 20

• Keratin containing scales
• Waterproof skin & prevent dehydration in dry air
• Evolved amniotic eggs

Question 21

structural features of Birds?

Answer 21

• Bones have a honeycombed structure that makes them strong but light; they no internal organs; they are endotherms
• wings adapted for soaring on air currents (feathers made of keratin)

Question 22

When did mammals firstly appear on land?

Answer 22

225 million years ago,

Question 23

What are the two features of mammals?

Answer 23

Hair and mammary glands

Question 24

Which three major groups are mammals divided into? What are the structural features and representative respectively of these three groups?

Answer 24

A. Monotremes- platypus, echidnas
B. Marsupials- kangaroos and koalas (pouched animals)
C. Eutherians- monkey, apes, humans (placental animals)

Question 25

When did primates originate?

Answer 25

65 million years ago

Question 26

What are the structural features of primates?

Answer 26

• were small, arboreal mammals
• have limber shoulder joints
• dexterous hands
• eyes of primates are close together on the front of the face

Question 27

What two main groups are primates classified into? And what are the representatives of these two groups?

Answer 27

1) Prosimians – lemurs, lorises, pottos, tarsiers

2) Anthropoids- monkey, apes, humans

Question 28

How long is the history of human and chimpanzee?

Answer 28

5-7 million years ago, human and ages diverged

Question 29

What is earliest bipedal walking Hominidae? And when did it firstly appear?

Answer 29

afarensis, 4 million years ago

Question 30

When did all species of Australopithecus extinct?

Answer 30

.4 million years ago

Question 31

When did Homo habilis appear firstly?

Answer 31

2.5 million years ago

Question 32

What structural traits does Homo habilis have?

Answer 32

Enlarged brains, brain cavity, made handmade stone tools

Question 33

When did Homo erectus start global dispersal?

Answer 33

1.8 million years ago

Question 34

When compared with Homo habilis, what special evolutional features does Homo erectus have?

Answer 34

A. taller than Homo habilis and had a larger brain capacity
B. resided in huts or caves, built fires
C. made clothes from animal skins, and designed stone tools that were more refined than the tools of Homo habilis

Question 35

Development of animals

Answer 35

Zygote→ Blastula→ Gastrula→ Larva→ Adult

Question 36

What structural differences are between Neanderthals and homo sapiens?

Answer 36

Neanderthals had slightly heavier browridges and less pronounced chins, but their brains were slightly larger than humans.

Question 37

What are the two hypotheses on the origination of homo sapiens?

Answer 37

A. Multiregional model- modern humans evolved simultaneously in different part of the world.
B. Monogenesis Model- human arose from a single archaic group in Africa. (based on molecular DNA in mitrochondria)

Question 38

What are the three stages of cultural evolution?

Answer 38

A. Nomads (2 million years ago) made tools, organized communal activities and divided labor, produced beautiful ancient art.
B. Development of agriculture in Africa and Eurasia about 10,000 to 15,000 years ago. People settled permanent and formed cities.
C. Industrial Revolution, which began in the eighteenth century. Since then, new technology has escalated exponentially, people formed high-tech society.

Question 39

Concept: metamorphosis

Answer 39

the process of transformation from an immature form to an adult form which two form are totally different