Characteristics of animals Feeding- Must consume food. Does not produce it’s own food. Heterotrophic Respiration- Takes in oxygen and gives off CO2 Circulation-Has a means to distribute O2 Excretion- Means to eliminate waste Response –Respond to environment using specialized cells Movement-Able to move from one place to another. Mobile Reproduction- Able to reproduce sexually Eukaryotic- Cell with cell membrane and true nuclei.

Development of animals 1. Fertilization- sperm and egg join together (1n+1n=2n) 2. Mitosis of 2n cell = 2 cells, 4 cells, 8 cells,.16…32……. 3. Now get a hollow ball of cells called a BLASTULA that is filled with fluid 4. One side of blastula pinches inward to form GASTRULA 5. Hole that forms is called BLASTOPORE

BLASTULA GASTRULA

Animals Grouped by Fate of Blastopore Depending on what becomes of blastopore animals are divided into 2 groups 1. blastopore becomes mouth- PROTOSTOME(then second opening becomes anus) 2. blastopore becomes anus –DEUTEROSTOME(then second opening is mouth) Cells then differentiate for animal to reach adulthood.

Gastulation is what forms an inside and an outside of the organism. Inside layer called ENDODERM-becomes lining of the gut Outside layer of cells called ECTODERM-becomes skin and nervous system Some animals have a 3 rd middle layer called MESODERM-becomes the circulatory system, muscle system, and excretory system

Symmetry Animals can be divided into groups by their symmetry.

Asymmetry No symmetry Asymmetrical sponges

Radial symmetry Organism can be divided along any plane Jellyfish

Bilateral Symmetry Organism has left and right Anterior and posterior Front and Back Ventral and Dorsal

Animals with 3 body layers Animals with 3 body layers(Ectoderm,Endoderm, and Mesoderm) can be divided into 3 groups depending on how much of their body cavity is covered by mesoderm. Body cavity is called COELOME

Acoelomate No body cavity. Digestive tract runs length of body Flatworms Solid all the way through

Pseudocoelomate(false cavity) Space between endoderm and mesoderm is filled with fluid Coelome not compltely covered by mesoderm, just partially 1 way digestive tract Round worm

Coelomate(true body cavity) True body cavity all surrounded by mesoderm Fluid filled Contains specialized organs Humans, Earthworm

Cephalization Concentration of sense organs and nerve cells in the anterior region. Shows high degree of complexity

Feeding and Digestion Intracellular-inside each cell. Extracellular- food is broken down in digestive cavity or tract. Then nutrients are absorbed

Respiration Exchange of gasses. Oxygen and Carbon Dioxide Lungs and gills have larger surface areas( alveoli and slits) in order to have more contact with air or water.

Circulation Open System Closed System Blood is partially contained in vessels.Fluid is pumped into spaces or sinuses where organs are bathed in the fluid for oxygen exchange. Ex- grasshopper Blood is pumped by heart or heart like organ through vessels throughout the body Ex- Humans

Excretion Removal of metabolic waste while controlling the amount of water( osmoregularity) Ammonia, Urea, Uric Acid- depends on animal

Response Nervous systems gather stimuli from environment and produce a response. Centralization- nerve cells concentrated in one area Cephalization- nerve tissue found in anterior region Specialization- complex animals have sense organs that detect specific stimuli, like eyes detect light, ears detect sound waves.

Movement and Support Hydrostatic Skeletons: muscles surround a fluid filled cavity like an earthworm.

Exoskeleton: outer covering made of chitin found in insects. Must molt occasionally due to increase in body size. Endoskeleton: support system located inside the body. Can allow for greater size.

Reproduction Asexual: copy of parent- Fragmentation, budding Sexual: combination of 2 different gametes External Fertilization: Egg fertilized outside of female body Internal Fertilization: Egg fertilized inside of female body.