Chapter 11 Animal Diversification

What three major problems did animals have to solve to thrive on land?

1. Respiration transition. On land needed regular ability to breath air. 2. Gravity. Needed structural support to resist the pull of gravity. 3. Egg Desiccation. Required egg that resisted drying out when exposed to air.

Name the four key distictions of divide extant animals:

1. Tissues or not; 2. radial or bilateral symmetry; 3. protostome or deuterostome development, and 4. growth through molting or through continuous skeletal enlargement.

According to the fossil record, the first humans appeared approximately ________ years ago.

100,000

What characteristics are used to describe animals?

All are multicellular; all eat other organisms; all can move during at least one stage of development.

What is a vertebrate?

Animal with a backbone

What animal phylum is Earthworm, polychaete worm, and leech?

Annelida

What animal phylum is Insect, crab, spider, millipede?

Arthropada

What is the only animal phylum to have over one million described species?

Arthropods

What animal phylum is Shark, snake, human, bird, frog?

Chordata

What animal phylum is Starfish, sea urchin, sea cucumber?

Echinodermata

Explain why an ectother, such as a snake, requires only an occasional meal, while an endotherm, such as a mouse, requires frequent meals to survive?

Energy derived from food is utilized for the heat production. Endotherms require more food to maintain a constant internal temperature.

What advantages did walking on two feet instead of four give?

Energy efficiency; having hands free to carry things and use tools.

What anatomical characteristics do humans share with other primates?

Eyes; arms; fingers and toes.

Why were jaws and fins an important adaptation for survival in the evolution of fish?

Fins get you to organisms you're going to eat and jaws capture and kill it.

The first evidence of stone tools occurs with what species of hominins?

Homo habilis

What hominins probably lived at the same time as modern humans, although they are now extinct?

Homo neanderthalensis

How did the vertebrates solve major problems to thrive on land?

Lungs to breathe, limbs modified vertebrates, amniotic egg develop waterproof egg.

What type of mammal are Kangaroos and wallabies?

Marsupials

What animal phylum is Squid, octopus, snail, and clam?

Mollusc

What type of mammal are platypuses and spiny echindas?

Monotremes

What type of mammal are Tigers and deer?

Placentals

Animal having jaws and paired fins

Sharks and bony fish

Snakes should not wear sweaters - why?

Snakes depend on an outside source of heat so if they have a sweater then it prevents the snake from producing its own heat.

Why are birds now grouped with reptiles even though they have feathers and are endothermic?

The similarities in bones especially bones of the skull and legs and DNA sequence.

Characteristics found in the slug not found in any segmented worms:

The slug has a radula, broad foot and produces a protective slime.

All land vertebrates are tetrapods. What does this mean?

They have four feet. Tetra=four. Poda=feet

Why do we say that amphibians live a double life?

They live on land and in water

Why is the development of a bipedal gait so important in the hominins?

They were able to walk on two feet instead of four

The lineage that first separated from the common ancestor of all animals, and retains many of those primitive features to this day, includes what modern organism?

a sponge

Which animal possesses radial or bilateral symmetry?

all animals possess either radial or bilateral symmetry

Animal that lay eggs in water, aquatic larvae, but adults have lungs and can live on land.

amphibians

Which trait is unique to arthropods?

an exoskeleton

Animal characteristic of segmented round worm

annelids

Animal having hard exoskeleton of chitin, walking legs (insect with wings)

anthropods

What insect group has the most species currently named by scientists?

beetles

Animal having notochord, dorsal hollow nerve chord, post anal tail (monkey)

chordates

Animal having polyp and medusa forms, stinging cells on tentacles, radial symmetry (jellyfish)

cnidarians

Animal having radial symmetry as adults, tube feet for locomotion, hard skeleton under spiny skin (starfish).

echinoderms

What are examples of chordates?

fish; humans; and frogs.

Animal having flattened wormlike body form

flatworms

Why is the amniotic egg considered a key evolutionary innovation?

it greatly increases the likelihood of survival of the eggs in a terrestrial environment.

The two most important evolutionary innovations in vertebrates, which resulted in their eventual domination among the large animals, were:

jaws and amniotic eggs

Sponges are sessile, meaning that they:

live attached to a solid structure and do not move around.

Animal having hair and mammary glands

mammal

Animal having shell, mantle, foot, radula (octopus)

molluscs

Marsupials and _________ combine to make a monophyletic assemblage?

placental mammals

In cnidarians, cnidocytes are primarily used for?

prey capture and defense

The molluscan mantle is used primarily for:

producing the shell

Animal that lay eggs on land, scaly skin, some are exothermic and some endothermic.

reptile

Which animal is a tetrapod that does not produce amniotic eggs?

salamander

Animal lacking true tissues, porous body, a filter feeder.

sponge

Which came first, the chicken or the egg?

the egg, because the amniotic egg evolved well before the first birds.