Chapter 32Section 2

Invertebrates & Vertebrates

Invertebrate Characteristics

• Adult invertebrates show tremendous amount of morphological diversity

Symmetry• Radial- jellyfish

• Bilateral- motile lifestyle- California sea hare

Segmentation• Segmentation- body composed of

repeating similar units

• Examples: earthworm & crayfish

Support of the body• Sponges = soft tissue

• Round worms = fluid-filled cavities

• Exoskeleton- rigid outer covering that protects the soft tissues of many animals, especially arthropods

Respiratory System

• Animals give off CO2 by a means of gas exchange

• Gills- organs that consist of blood vessels surrounded by a membrane and are specialized for gas exchange in water

Circulatory System

• Moves blood to transport O2 & nutrients to cells

• CO2 & waste is moved away from cells

• Sponges & cnidarians have no circulatory system

Circulatory System• Arthropods have an open-

circulatory system- circulatory fluid is pumped by the heart through vessels and into the body cavity & returned to the vessels

Circulatory System• Annelids & mollusks have a

closed circulatory system- blood is pumped by a heart and circulates through the body in vessels that form a closed loop

Reproduction• Sexual & asexual reproduction

• Earthworm

• Hermaphrodite- organism that produces both male and female gametes, allowing an individual to function as both male & female

Development• Indirect development- immature form

of organism that is morphologically different from adult stage- Larva

• Direct development- young animal is born or hatched with the same appearance as adult- no larva stage

Vertebrate Characteristics

• Fishes, amphibians, reptiles, birds & mammals

Segmentation & body support

• Vertebrate- repeating bony units of the backbone

• Terrestrial vertebrates evolved from aquatic vertebrates

• Endoskeleton- internal skeleton made of bone and cartilage

Body Coverings• Integument- outer covering of an

animal

• What different types of integuments do you know of? HINT: think of different animals & environments

Respiratory• Lungs- organs for gas exchange

composed of moist, membranous surfaces deep inside the animal’s body

Circulatory• Vertebrates have a closed

circulatory system with a multi-chambered heart

• Multi-chambered heart separates oxygenated and deoxygenated blood

Digestive• Digestion occurs in the gut, which

runs from the mouth to the anus

Excretory• Kidneys- filter wastes from the

blood while regulating water levels in the body

Reproduction• Fish & amphibians- eggs & sperm

are released directly into water

• Reptiles, birds & mammals- egg & sperm unite in body

REVIEW!!!• Identify the function for body

coverings.

• Compare the structure of endoskeletons & exoskeletons.

• How might the segmentation of arthropods help them survive?