Taxonomy

1
Taxonomy Chapter 28 What is an Animal?
2

• Animal Characteristics
• 1. Eukaryotes
• 2. Multicellular
• 3. No cell walls or chloroplasts
• 4. Heterotrophic

3

• 5. Many types of movement
• a. Sessile dont move (barnacles)
• b. Mobile early, sessile adults (coral)
• c. Sessile larvae, mobile adults (jellyfish)
• d. Mobile able to move

4

• 6. 1st evolved in water
• -more food than on land
• -needed to expend less energy
• 7. Ingest digest food w/in body
• -digestive system is specialized to diet
• 8. Cells specialized into tissues organs to
  carry out specific functions

5

• Development
• 1. Fertilization when egg sperm join to form a
  zygote
• -occurs only during sexual reproduction

6

• 2. Cell division occurs by mitosis (cleavage)
• -embryo mass of dividing developing cells
• -org. at an early stage of growth/development
  
• -blastula hollow ball of cells filled w/ fluid
• -humans-5 days after fertilization

7
(No Transcript)
8

• 3. Gastrulation cells on 1 side of the blastula
  push inward
• -gastrula structure of 2 layers w/ an opening
  at 1 end

9

• -layers formed in gastrula
• a. ectoderm outer cell layer that will
  develop into skin nervous tissue
• b. endoderm inner cell layer that will
  develop into digestive system
• c. mesoderm middle layer that may form
  later, will develop into all other systems

10

• -2 types of gastrulation
• a. Protostomes opening of gastrula develops
  into mouth
• -snails, earthworms, insects
• b. Deuterostomes mouth doesnt form from
  gastrula opening
• -starfish, fish, amphibians, birds,
  reptiles, mammals

11
(No Transcript)
12

• 4. Growth Development
• -cells differentiate become specialized for
  their specific function
• 5. Adulthood
• -org. reach sexual maturity, reproduce,
  process begins again

13

• Symmetry
• -arrangement of body structures
• -allows for specific movement
• 1. Asymmetry not symmetrical, irregular body
  shape
• -usually sessile

14

• 2. Radial symmetry can be divided into equal
  halves by multiple plans thru center
• -allows org. to detect capture prey from
  many angles

15

• 3. Bilateral symmetry can be divided into right
  left halves along 1 plane
• -more effective movement

16

• Body plans
• -develop 3 embryonic layers (ecto/meso/endoderm)
• -may have fluid-filled body cavity that allows
  for increased size

17

• Types
• a. Acoelomates no body cavity
• -flatworms
• -solid, compact body

18

• b. Pseudocoelomates space between endoderm
  mesoderm filled w/ fluid
• -roundworms
• -allows for more effective movement
• -1-way digestive tract

19
(No Transcript)
20

• c. Coelomates fluid-filled space completely
  lined w/ mesoderm
• -one-way digestive tract
• -organs cushioned/protected
• -efficient movement

21

• Protection Support
• 1. Shells

22

• 2. Exoskeleton hard outer covering that provides
  support for body framework
• -protect soft areas, prevent water loss
• -secreted by skin
• -place for muscles to attach
• -usually found in invertebrates animal w/out a
  backbone

23

• 3. Endoskeleton internal skeleton covered by
  cells that supports body
• -protects internal organs
• -muscle attachment

24

• -e.g.
• -invertebrates-sea stars- made of calcium
  carbonate
• -Vertebrate animals w/ endoskeleton a
  backbone (bilateral sym.)
• -shark-made of cartilage
• -bony fish ? mammals- made of bone