1. Animal Diversity
Chapter 23

2. animal characteristics
All animals share a unique set of derived characteristics.
Animal cells are supported by
collagen.
three-stranded protein
found in bone, skin, ligaments, fingernails, and hair

3. animal characteristics
Animals are diploid and usually reproduce sexually.
diploid parents produce diploid offspring
Diploid cells have two copies of each chromosome: one copy from the mother and one from the father
do not have free-living haploid life stages

4. animal characteristics
Most animals have Hox genes.
Hox genes tell embryonic cells which body part to become.
Mutations in Hox genes led to the vast diversity of animal species.
head
tail
fruit fly genes
human
HOX-B genes

5. animal phyla Vertebrates have an internal segmented backbone.
Invertebrates do not have a backbone.
Invertebrates encompass most animal groups.

6. Animal Classification
Three criteria are used to categorize animals.
body plan symmetry
tissue layers
developmental patterns
gastrovascular cavity
mouth
mesoglea
oral arms
tentacles
blood vessels
brain
hearts
muscle
segment
nerve cord
mouth
digestive track

7. Animal Classification
There are two types of body plan symmetry.
bilateral symmetry: body divides equally along one plane
Bilateral symmetry can be divided equally along only one plane, which splits an animal
into mirror-image sides.

8. Animal Classification
There are two types of body plan symmetry.
Radial symmetry: body arranged in circle around a central axis
Animals with radial symmetry have body parts arranged in a circle around a central axis.

9. ASYMMETRICAL
Animals that have NO symmetry
SPONGES

10. Body Surfaces Anterior – toward the head Posterior – toward the anus
Dorsal – toward the spine (back)
Ventral – toward the stomach (belly button)
Lateral – to the side
Oral – side where the mouth is located
Aboral – side opposite the surface where the mouth is located

11. Characteristics of Animals
All multicellular
Eukaryotes (cells with nucleus & organelles)
Ingestive heterotrophs (take in food and internally digest it)
Store food reserves as glycogen
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12. Lions Feeding (Ingestion)
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13. Support Systems Have some type of skeletal support
Endoskeleton is internal and made of cartilage &/or bone
Exoskeletons found in arthropods
Cover the outside of the body
Limit size
Must be molted making animal vulnerable to predators
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14. Cicada Molting Exoskeleton
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15. Support Systems
Worms and echinoderms (starfish) have fluid-filled internal cavities giving them support
Called hydrostatic skeletons
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16. Movement
Animals such as sponges may be sessile (attached & non-moving)
Animals that move very little are said to be sedentary (clam)
Animals that can move are motile
Have muscular tissue to provide energy for movement
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17. SESSILE
SEDENTARY
Chiton
Sponge
MOTILE
Cheetah
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18. Reproduction in Animals
All animals are capable of sexual reproduction
Some animals like sponges and earthworms are hermaphrodites producing both eggs and sperm
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19. Leeches Exchange Sperm During Mating
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20. Reproduction in Animals
Females of some animals produce eggs, but the eggs develop without being fertilized
Called Parthenogenesis
New offspring will be all female Parthenogenesis occurs in some fishes, several kinds of insects, and a few species of frogs and lizards
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21. Parthenogenesis in the Komodo Dragon
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22. Mating and Mating Behaviors
Female
Beetles Mating
Young
Courtship
Male
Mating and Mating Behaviors
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