1. Among the Characteristics Unique to Animals Is

1. Among the characteristics unique to animals is a. gastrulation. b. multicellularity. c. sexual reproduction. d. flagellated sperm. e. heterotrophic nutrition.

2. Acoelomates are characterized by a. the absence of a brain. b. the absence of mesoderm. c. deuterostome development. d. a coelom that is not completely lined with mesoderm. e. a solid body without a cavity surrounding internal organs.

3. Which of the following subdivisions of the animal kingdom encompasses all the others in the list? a. Protostomes b. Bilaterians c. Radians d. Eumetazoans (those with true tissues) e. Deuterostomes

4. Which characteristic below is shared by plants, fungi, and animals? a. They all have cell walls. b. All are multicellular eukaryotes. c. All obtain nutrition through ingestion. d. All possess the same types of tissues.

5. Animals probably evolved from colonial protists. How do animals differ from these protist ancestors? a. The protists were prokaryotic. b. Animals have more specialized cells. c. The protists were heterotrophic. d. Animals are able to reproduce.

6. During the development of most animals, cleavage leads to _____. a. the formation of a zygote b. the formation of a blastula c. the formation of a gastrula d. fertilization e. metamorphosis

7. Which example below is a common feature of all animals? a. bilateral symmetry b. obtain nutrition through absorption c. a true coelom d. limited to sexual reproduction e. none of the above

8. Ectoderm can give rise to _____; mesoderm can give rise to _____; endoderm can give rise to _____. a. muscle ... the outer covering of the animal ... the central nervous system b. the lining of the digestive tract ... muscle ... the outer covering of the animal c. the central nervous system ... the outer covering of the animal ... the lining of the digestive tube d. muscle ... the outer covering of the animal ... the lining of the digestive tube e. the central nervous system ... muscle ... the lining of the digestive tube

9. A true coelom is _____. a. a body cavity lined with tissues derived from the endoderm b. a body cavity lined with endoderm and mesoderm c. a body cavity lined with mesoderm

10. A pseudocoelomate animal is one in which the body cavity is _____. a. bounded completely by mesoderm b. filled by a solid mass of mesoderm c. bounded completely by endoderm d. bounded partly by ectoderm e. bounded partly by mesoderm

11. The difference between pseudocoelomates and coelomates is that pseudocoelomates _____, whereas coelomates _____. a. do not have a body cavity ... have a body cavity b. exhibit radial symmetry ... exhibit bilateral symmetry c. are protostomes ... are deuterostomes d. have a body cavity partially lined with tissue derived from mesoderm ... have a body cavity completely lined with tissue derived from mesoderm

12. The presence of a coelom is advantageous because _____. a. it allows for a third embryonic germ layer b. it permits the development of an open circulatory system c. it allows room for the development and movement of internal organs d. it is necessary for a complete digestive tract e. all of these

13. Which example below is not a major feature of animal body plans? a. symmetry b. type of eye c. tissues d. body cavities e. mode of development (protostome or deuterostome)

14. Protostomous animals are those in which the _____. a. blastopore forms the mouth b. ectoderm forms the muscles c. digestive tract is incomplete d. mesoderm forms appendages

15. One of the two taxa that molecular studies divide the protostomes into is called Ecdysozoa. What characteristic is this taxon named for? a. a horseshoe-shaped crown of ciliated tentacles b. a trochophore larva c. the secretion of stiff external skeletons that must be shed to allow for growth d. segmented bodies Answers: 1. a 2. e 3. d 4. b 5. b 6. b 7. e 8. e 9. c 10. e 11. d 12. c 13. b 14. a 15. c