Introduction to Animals/ Simple Animals

Mrs. Wetzel Biology

What is an animal?

MulticellularEukaryoticHeterotrophNo cell walls

Two Groups of Animals

What are the two groups of animals?

Two Groups of animals

What are the two groups of animals?Vertebrates Invertebrates

Invertebrates

No backbone or vertebral columnRange from dust mite to giant squid

Vertebrates

Have a backboneMake up only five percent of the animal

kingdom

Animal Survival

Feeding- all animals are heterotrophic and have a variety of ways to obtain nutritionFilter feedersParasiteDetritovoresOmnivoresHerbivoresCarnivoreSymbiont

Animal Survival

Respiration= gas exchange

Animal Survival

Circulation= movement of oxygen, nutrients, waste productsSimple animals= diffusionComplex animals= circulatory system

Animal Survival

Excretion= removing wasteNot just poop & peeAmmonia= cellular waste- toxic

Animal Survival

Response= “nervous system”Simple animals = sensory receptorsMore complex= cephalization in other words a

concentration of sensory organs near the head of an organism.

Animal Survival

Movement-Simple animals= sedentaryMore complex= highly mobile

Animal Survival

Reproduction- Simple= asexualMore complex= sexual

Trends in Animal Evolution

Cell Specialization- as animals evolved their cells have developed the ability to conduct specific activities. A sponge has a few cells to perform the limited number of jobs of the sponge. Humans- the most complex animal has thousands of specialized cells to perform the thousands of jobs of a human.

Trends in animal Evolution

Early development- all animals look exactly the same during the early stages of development Primordial germ layers are

cells that have not “Specialized yet” the three major germ layers are;

Ectoderm Mesoderm Endoderm

Germ Layers

Germ LayersAs soon as fertilization occurs the zygote

begins to divide- it divides and divides eventually forming a hollow ball- the ball begins to fold in on itself forming a bowl

Germ Layers

The in folding is called a blastopore Depending on the

animal the blastopore can develop into two things

Deuterostomes= mouth

Protostomes= anus All Vertebrates are

deuterostomes

Germ Layers

All animals primordial germ layers are endoderm, ectoderm, and mesodermEndoderm- digestive tract and respiratory

systemMesoderm= muscle, circulatory, excretory,

reproductive systemEctoderm= skin, sense organs, nerves

Gastrulation

Formation of the germ layers is called gastrulation- it is the MOST important time of your life.

Symmetry

RadialBilateralAsymmetrical

Simple= AsymmetricalSlightly more complex= radialMore complex= bilateral

Cephalization

** The concentration of sense organs toward the anterior “head” of the body

Body cavity

Animals have a body cavity filled with fluids involved in circulation, excretion, and digestion

Phylum Porifera

Phylum porifera contains the sponges Sponges do not look like

animals but they do have the right characteristics

Heterotrophic, multicellular, no cell walls,

Phylum Porifera

Sponges are asymmetrical The body of a sponge forms a tube that

water passes through.Collar cells are specialized cells that have

flagella to keep water flowing at a steady pace

Phylum Porifera

Feeding: Sponges are filter feeders. As water passes through the sponge it strains out the food bits like a sieve

Phylum Porifera

Circulation/ Excretion/ RespirationSponges rely on the movement of water for

these mechanismsWastes diffuse over the cell membranes back

into the water and get carried away

Phylum Porifera

Response- Nothing in the way of a nervous system- they do produce toxins that keep predators from eating them

Phylum Porifera

Reproduction- Most sponges are hermaphrodites meaning that each individual functions as both male & femaleSexual= internal fertilization- sperm is

released by one sponge and carried by water currents to another sponge where it can meet up with eggs

Asexual- budding

Phylum Porifera

Larva- sponge larva looks nothing like an adult sponge- it is mobile and can swim around eventually settling somewhere on the ocean floor where it will then mature into an adult non- motile sponge

Phylum Porifera

Ecology- Important habitats for marine animalsSymbionts to bacteria, algae, & plantlike

protistsSponges

Phylum Cnidarian

What?Soft bodied carnivorous animal with stinging

tentacles arranged in a circle around the mouth

Phylum Cnidarian

Body Plan- Radial symmetry- central mouth surrounded by tentacles. Body wall surrounds the G.V.C.Two life stages

Polyp- non-motileMedusa- motileDimorphic life form is unique to cnidarians

Phylum Cnidarian

Tissue LayersEpidermis= outsideMesoglea= middle layerGastroderm= Lining of the G.V.C

Phylum Cnidarian

Feeding- grab food with tentacles- paralyze it using nematocyst- pull food into G.V.C.

Any material that can not be digested is brought back up and spit out the mouth

Phylum Cnidarian

Respiration/ Circulation/ ExcretionRely on water & diffusion through cell

membrane

Phylum Cnidarian

Response- Nerve Net- nerve cells Statocysts- determine gravityOcelli- simple eyespot can detect light

Phylum Cnidarian

Movement- Hydrostatic skeleton- fills with water or contracts- pushes water out for jet propulsion-like movement

Phylum Cnidarian

Reproduction- asexual or sexualSexual reproduction takes place in the

waterAsexual= budding

Classification

Class Scyphozoa= jelly fish Hydrozoa- hydras, Portuguese Man of

War= colonial hydraClass Anthozoa= sea anemones & coral

Phylum Cnidarian

Ecology- VIP symbionts for photosynthetic marine life, provide habitats