question... The most primitive multi-cellular animals produce what?
Options:
- (A) Electrical energy
- (B) eggs and sperm
- (C) harmful substances
- (D) scarce resources
- (E) Organic compounds
- (F) Chemical energy
- (G) fur and fat
- (H) aerobic capacity
answer... Adult sponges produce eggs and sperm. Sponges are the most primitive multicellular animals. The most primitive multi-cellular animals produce eggs and sperm.
The answer is (B)

question... Invertebrates can be what?
Options:
- (A) people
- (B) scarce resources
- (C) vertebrates
- (D) deposit feeders
- (E) Catch prey
- (F) major threat to health
- (G) more abundant
- (H) planets
answer... Earthworms are important deposit feeders that help form and enrich soil. Earthworms by Casey Earthworms are invertebrates. Invertebrates can be deposit feeders.
The answer is (D)

question... What do all vertebrates have that invertebrates don't?
Options:
- (A) sensory neurons
- (B) fur and fat
- (C) bones and joints
- (D) a jaw bone
- (E) kinetic energy
- (F) Chemical energy
- (G) a spinal column
- (H) a set of gills
answer...
Vertebrates are all chordates that have a backbone. Invertebrates are animals who lack a backbone or spinal column. Vertebrates are all chordates that have a spinal column.
The answer is (G)