Intro to Animal Diversity Chapter 32. Slide 2 of 17 Animalia – General Notes 1.3 million species ...

Intro to Animal Diversity

Chapter 32

of 17

Animalia – General Notes

1.3 million species 300K plant species 1.5 million fungi >10 million bacteria

Animals ARE heterotrophs Plantae? Fungi? Protista?

Animals are multicellular Plantae? Fungi? Protista? Bacteria?

of 17

Animalia – General (Page 2)

Unique in the possession of muscular and nervous tissue

Lack cell walls Held together by structural proteins such as collagen Plants? Fungi? Bacteria? Protista?

Most reproduce sexually

Diploid stage is dominant in most

of 17

Fertilization Zygote (Mitosis) Cleavage Blastula

of 17

Embryology Notes

Cleavage – rapid series of mitotic divisions w/o cell growth in between What part(s) of the cell cycle would be proportionally

reduced during cleavage? Extended?

Blastula – Hollow ball of cells Cavity is called blastocoel

Gastrula – blastula gets “punched in” Embryonic tissue layers form from gastrulation Product of gastrulation called archenteron Blastophore is the opening of the archenteron

of 17

2 Quick Things

Some animals have a larval stage Immature, distinct form Undergoes metamorphosis to

become adult form

Hox genes Common in animals Genes that play an important role

in development

of 17

Animal Body Plans

There are 3 main types of animal body plans:

No symmetry Sponges

Radial symmetry Jellyfish and many primitive animals Central axis, and any cut through the axis results in

mirror images

of 17

Bilateral Symmetry

Most amphibians, reptiles, birds, and mammals

Produces a right and left sides that are mirror images of each other

Usually produces dorsal and ventral sides

Associated with cephalization Anterior (head) end Posterior (tail) end Concentration of sensory equipment at one end

Usually anterior end

of 17

Coelomate True coelom Fluid-filled body cavity between digestive tract & outer body wall True compartmentalization

Pseudocoelomate Triploblastic animals -- 3 tissue layers Cavity formed from mesoderm + endoderm

Acoelomate No cavity between alimentary canal and outer body wall

of 17

Germ Layers

Give rise to the tissues and organs of the animal embryo

Ectoderm is the germ layer covering the embryo’s surface

Endoderm is the innermost germ layer and lines the developing digestive tube, called the archenteron

of 17

Germ Layers

Diploblastic animals have ectoderm and endoderm

Triploblastic animals also have an intervening mesoderm layer; these include all bilaterians

A pseudocoelom is a body cavity derived from the mesoderm and endoderm

of 17

Why a body cavity (coelom)?

The separation between body wall and digestive tract have advantages Cushion suspended organs

From blunt force and other sources of physical trauma Increased structural support

Skeletal structure or hydrostatic skeleton Internal organs grow and move independently

Greater specialization = more advanced

of 17

Coelom Formation

In protostome development, the splitting of solid masses of mesoderm forms the coelom

In deuterostome development, the mesoderm buds from the wall of the archenteron to form the coelom

of 17

Fate of the Blastophore

The blastopore forms during gastrulation and connects the archenteron to the exterior of the gastrula

In protostome development, the blastopore becomes the mouth

In deuterostome development, the blastopore becomes the anus

Intro to Animal Diversity Chapter 32. Slide 2 of 17 Animalia – General Notes 1.3 million species ...

Documents

Transcript of Intro to Animal Diversity Chapter 32. Slide 2 of 17 Animalia – General Notes 1.3 million species ...