Animal Kingdom

Characteristics

Characteristics

• Eukaryotic

• No cell wall

• Reproduce sexually (embryo undergoes state of development)

• ingest/digest food

• mobile

Differences between vertebrates and invertibrates

Invertibrates: Don’t have a backbone, generally small, make up multiple phyla

Vertibrates: have a back bone, generally large, chordates

Characteristics used to classify animals

Levels of organization, #of germ layers, symmetry, body cavities, digestive system, segmentation, mobility, reproduction, nervous system

Levels of organization

• based on difference sin tissue and organ systems

• Tissue: a group of cells that perform similar functions

#of germ layers

• Ectoderm: outside (nerve tissue, skin, sense organs)

• Mesoderm: middle (muscles, blood, kidneys)

• endoderm: inner (lungs, liver, kidney, heart)

classified based on whether they have 1/2/3 layers

symmetry

• Asymmetrical body plans: irregular shaped body (sponge)

• Radial symmetry: can be divided along any plane and cut into roughly equal halves

• Bilateral symmetry: can be cut along one plane and divides into 2 equal halves

body cavities

• Coelum: fluid filled body cavity that holds organs in place/developes them

• Organs are contained in body cavity

• Can be:

  • coelomate: have

  • Acoelomate: without

  • pseudocoelomate is similar to coelom but lacks a layer of cells

• Advantages: allows for quick responses and movement and development of complex organs

digestive system

• No digestive system (sponges)

• Incomplete digestive system: only one opening, food goes in and waste comes out of the same hole

• Complete digestive system: digestive tube has 2 openings

• Protostome: mouth develops first

• Deuterostome: anus develops first

segmentation

• The division of the body into repetitive segments or sections

• Advantages: If one section is damaged, the rest continue to work. Mobility is also more effective

mobility,

• Most animals are mobile

• Sessile: some animals are stationary and stay in one place, but at some point in its early stages it had movement

reproduction

• Reproduce sexually

• produced by either external or internal fertilization

  • External: fertilization happens outside of the body

  • Internal: Gameters combine inside the body

*some animals like aphids reproduce sexually/asexually

nervous system

• Some have it, some don’t

• Cephalization:

  • nervous tissue is concentrated at one part of an organism (eg. the brain)

  • Ceph: means brain