INTRODUCTION TO INVERTEBRATES

SICENCE

IV BIMESTER

MS. MEMBREÑO

INVERTEBRATE CHARACTERISTICS

• A grasshopper and a spider are both invertebrates.

• Animals that do not have backbones are invertebrates.

• The main invertebrate groups are sponges, cnidarians, flatworms, roundworms, segmented worms, mollusks arthropods, and echinoderms.

SPONGES

CNIDARIANS (NY DEHR EE UNZ)

WORMS

MOLLUSKS

ARTHROPODS

ECHINODERMS

INTRODUCTION TO VERTEBRATES

SICENCE

IV BIMESTER

MS. MEMBREÑO

WHAT ARE THE CHARACTERISTICS OF CHORDATES AND VERTEBRATES• The animals you are probably most familiar with are members of the phylum

Chordata. Members of this phylum are called chordates.

• Most chordates, including all fish, amphibians, reptiles, birds and mammals, are vertebrates.

• A few chordates such as sea squirts and lancelets, do not have backbones.

CHORDATE CHARACTERISTICS

• At some point in their lives, all chordates have three characteristics: a notochord, a nerve cord, and pouches in the throat area.

• Most chordates also have a backbone.

LANCELETS

NOTOCHORD

• A notochord is a flexible rod that supports a chordate’s back. The name Chordata comes from this structure’s name.

NERVE CORD• All chordates have a

nerve cord that runs down their back. Your spinal cord is such a nerve cord. The nerve cord connects the brain to nerves in other parts of the body.

THROAT POUCHES• At some point in their lives,

chordates have pouches in their throat area. • In most vertebrates, the

pouches disappear before birth.• In fish and lancelets,

grooves between these pouches become gill s slits.

HOW DO VERTEBRATES CONTROL BODY TEMPERATURE

• Some vertebrates do not produce much internal heat. Therefore, their body temperatures change with the environment.

• Other vertebrates control their internal heat and maintain a constant body temperature.

ECTOTHERM • Amphibians, reptiles and most fish are ectotherms.• An animal that produces little

internal body heat is called an ectotherm.• Its body temperature changes

with temperature changes in its environment.

ENDOTHERM• Birds and mammals are

endotherms.• An endotherm is an animal that

controls the internal heat it produces and regulates its own temperature. • An endotherm has adaptations

such fur and feathers for maintaining body temperature.

VERTEBRATE DIVERSITY

CLICK ON THE LINK:

• http://www.slideshare.net/leannebenson/vertebrates20and20invertebrates-1

SKELETONS AND MUSCLES

SICENCE

IV BIMESTER

MS. MEMBREÑO

FAST FELINES• Which animal is the fastest sprinter? It is a

cheetah. The cheetah’s body structure and muscles allow it to reach speeds of up to 112 km/h in only three seconds. Its flexible spine enables the cheetah to extend its limbs to great lengths. This ability allows the cheetah to cover as much ground in one stride as a racehorse. The cheetah also has a high percentage of fast-twitch muscle fibers. These fibers provide power and allow the cheetah to reach its incredible speed faster than a race car can reach the same speed. It’s no wonder that the cheetah holds the title of “World’s Fastest Land Animal.”

1. What are two parts of a cheetah’s body that help it run fast?

2. Why do you think a cheetah’s speed is an advantage to the animal?

WHAT SUPPPORTS AND PROTECTS ANIMAL BODIES?• Imagine you are watching lions

moving slowly through tall grass.• They are surrounding a young zebra

that has wandered away from its mother.

• Flies buzz, and beetles chew on grass blades.

• Nearby, a snake slithers away from one of the lions.

• Unaware, the zebra continues to gaze.

WHAT SUPPPORTS AND PROTECTS ANIMAL BODIES?

• Think about all these different animals. Do they have anything in common?

• Yes, all of their bodies are supported by skeletons, which have similar functions.

SKELETON

• A skeleton is a framework that shapes and supports an animal, protects its internal organs, and allows it to move in its environment.

TYPES OF SKELETONS

ExoskeletonA hard outer covering.

BothShape and support, protect internal organs and help with movement.

EndoskeletonIs inside the body.

ENDOSKELETON

EXOSKELETON

JOINTSHave you ever tried to run without

bending your legs?

If you have, then you know it is difficult. Fortunately, most exoskeletons and endoskeletons have joints.

• A joint is a place where two or more parts of a skeleton meet.

WHAT IS THE ROLE OF MUSCLES?

• Muscles help animals move their body parts.• Tissues that contract or relax to create movement

are muscles.• When the muscles contract, or get shorter, they

squeeze blood through the vessels.

MUSCLES IN ENDOSKELETON

MUSCLES IN EXOSKELETON