test 2 6to

an animal that has the beginning of a backbone during one or more stages of development.

• Reptile
• Mammal
• Chordate

a hard, external covering of an animal

• carapace
• exoskeleton
• shell

the animal kingdom is divided into groups of

• vertebrates and invertebrates

• species and insects

• kingdoms and families

a cold-blooded animal whose body temperatures fluctuates with the temperature of its environments

• Ectotherm
• Amphibian
• Endotherm

an external structure that extends from the main body

• appendage
• extension
• limb

all fishes have appendages that are called

• gills
• scales
• fins

a warm-blooded animal that maintains a constant internal temperature

• Homeotherm
• Ectotherm
• Endotherm

a strong structural protein found in skin, hair, nails and feather

• keratin
• collagen
• elastin

an invertebrate that has a segmented body jointed appendage and usually an exoskeleton

• Mollusk
• Echinoderm
• Arthropod

a mainly aquatic arthropod that has a hard exoskeleton and two pairs of antennae

• Mollusk
• Insect
• Crustacean