The invertebrate family which includes mollusks, worms and insects up 95 percent of all living animals. Invertebrates have no vertebrae or backbone. The invertebrates are considered to be more simple, or not as far along the evolutionary ladder than animals with backbones. Some invertebrates have soft bodies, such as sponges; and some have hard bodies or exoskeletons such as insects. Their simplicity has led them to be recognized by some as a lower form of life. Through simplicity their existence has allowed some invertebrates to survive unchanged for millions of years.

1. Invertebrates have ____ .

a backbone
a body
warm blood
vocal chords

2. A good example of an invertebrate is ____ .

a human
a snake
a frog
a squid

3. Some invertebrate forms have been around for ____ of years.

hundreds
thousands
10s of thousands
millions

4. A large group of invertebrates are ____ .

insects
frogs
fish
reptiles

5. A sponge ____ a backbone.

has
does not have
absorbs
needs

6. Invertebrates are ____ than vertebrates.

more complex
smarter
simpler
fewer

7. Invertebrates are called ____ forms of life.

lower
fatter
thinner
higher

8. An invertebrate doesn't have ____ .

a body
legs
eyes
a skull

9. Invertebrates need ____ .

food
shelter
warmth
a place to rest

10. Because they are so simple, invertebrates are ____ creatures.

unsuccessful
successful
terrible
scarey

Your score is out of 10.