Introduction to Animals

*List as many characteristics as you

can that define something as an

“ANIMAL”...

CHARACTERISTICS of ANIMALS

*to be an “animal” it must:

MOVE

MULTICELLULAR

EAT (use energy)

“BREATHE”

GROW

REPRODUCE

RESPOND to a STIMULUS

STORE ENERGY as GLYCOGEN

?????????

MOTILE:

*the ability to MOVE

by...

“limbs” = walking

“fins” = swimming

“wings” = flying

“false foot” = ??? (pseudopod)

WHEN did animals 1st

appear on Earth?:

700-800 M.Y. ago

VERTEBRATESvs.

INVERTEBRATES

*presence of a backbone

RADIAL SYMMETRY =>“circular”

starfish, jellyfish, marine worms

tend to be slow

Have a TOP or “DORSAL” surface

have a BOTTOM or “VENTRAL” surface

“ventral”

“dorsal”

BILATERAL SYMMETRY =>

fast-moving

also have “dorsal” & “ventral” side

•Has an ANTERIOR or “front”•has a POSTERIOR or “back”

•has a “left” & “right”

*more complex/ advanced than radials

EGG

+ SPERM = ZYGOTE

ZYGOTE

“cleavage”

ZYGOTEetc...

BLASTULA

ZYGOTEetc...

*certain cells move inward

GASTRULA

“ectoderm”

“blastopore”

“endoderm”

*D E U TE R O S TO M E S :(blastopore ---> anus)

*P R O TO S TO M E S :( b la s t o p o r e - - - > m o u t h )

3 c e ll la y e r s f o r m in most

a n im a ls :* ENDODERM (inner)

-dig. tract, resp. system

* MESODERM (middle)-circ. system, muscles, rep. system, exc. system

* ECTODERM (outer)-skin, nerves, sense organs

I. HYDROSTATIC skeleton:

*muscles that surround & are supported by water

(roundworms & earthworms)

II. EXOSKELETON:* “hard shell”… muscles att. to the inside of shell

(insects & crustaceans)

* limits mobility & growth

III. ENDOSKELETON:* rigid framework inside an animal (protects less)

(vertebrates/humans)* allows movement & growth

I. MOST PRIMITIVE*A cavity where food is partially digested before moved into cells to complete the process

(flatworms)

II. MEDIUM SOPH.*a two-way digestive system*digested & undigested food mix

(cnidarians)

III. ADVANCED*food takes a one-way path*w/ special cells to absorb nutrients

(fish)

*Nearly ALL animals are capable of sexual reproduction.

hermaphrodite

*An animal w/ fully functioning male & female rep. structures is a:

(An advantage for members of small populations that seldom encounter

others of the same sp.)

*timed gamete production*

Asexual

sexual

Numbers of Living Species of Animals in each Phylum There are over one million species of animals that have been described. Some biologists estimate that up to 50 million more remain to be discovered. Of those that have been described, approximately 86% are insects . About 300,000 species are beetles (order Coleoptera ). The numbers of described species in each phylum of animals (other than the insects ) are shown below. Note that these are only rough estimates . The estimates from other sources may vary considerably.

PHYLUM Numbers of Living Species of Animals (exclusive of insects) No. Sp ecies

Arthropoda 97,000

Mollusca 50,000

Vertebrata 47,000

Protozoa 35,000

Platyhelminthes 20,000

Annelida 15,000

Nematoda 12,000*

Porifera 9,000

Cnidaria 9,000

Echinodermata 7,000

Ectoprocta 4,500

Uro chordata 3,000

Rotifera 1,800

Nemertea | 900

Acanthocephala | 700

Gastrotricha | 450

Tardigrada | 400

Sipuncula | 250

Nematamorpha | 230

Kinorhyncha | 150

Species Interactions - Symbiosis

• Mutualism - both species benefit from the relationship


• Commensalism - one species benefits from the relationship while the other is not affected


• Parasitism - one species benefits from the relationship while the other is harmed

*The End*

Introduction to Animals

Education

Transcript of Introduction to Animals