Chapter 24 Terms

Section 1

Invertebrates- animals w/o a backbone

exoskeleton – hard, waxy covering on outside of the body that provides a framework for support

Vertebrates-animals w/a backbone

endoskeleton – support framework housed within the body

Animal Cells vs Plant Cells- plant cells have a cell wall making them rigid – animal cells do not have a cell wall

Hermaphrodite- produce both sperm and eggs in the same body

Zygote-the cell resulting from the union of a male and female gamete, until it divides; the fertilized ovum.

Fertilization-union of gametes

Internal Fertilization- Gametes unite inside the body

External Fertilization- Gametes unite outside the body

Blastula-single layer of cells surrounding a fluid-filled space and is formed early in the development of an animal embryo

Gastrula – structure made up of 2 layers of cells early in the development of an animal embryo

Endoderm – inner layer of skin digestive organs & digestive tract

Ectoderm – outer layer of skin nervous tissue & skin

Mesoderm – middle layer of skin muscles, circulatory–respiratory-

excretory system

Section 2

Symmetry – refers to a balance in proportions of an object or organism

Radial symmetry – adaptation that enables the animal to detect & capture prey coming toward it from any direction

Bilateral symmetry – can be divided down it’s length into similar right and left halves that form mirror images of one another

Asymmetry – animal that’s irregular in shape

Cephal- combining form meaning head

-itis - combining form inflammation

Anterior – head end

posterior – tail end

Cephalization- tendency to concentrate nervous tissue and sensory organs at the anterior end

dorsal – backbone side

ventral – belly side

coelom – body cavity completely surrounded by mesoderm

pseudocoelom – fluid filled body cavity partly lined with mesoderm

aceolomate – animals with three cell layers with a digestive tract but no body cavities

Protostome- animal with a mouth that develops from the opening of the gastrula -simple animals, earthworms, insects

Deuterostome – animal in which the anus develops from the opening in the gastrula -complex animals, fishes, birds, humans

Segmentation- the division of bodies or body plans into a series of semi-repetitive segments

Section 3 Sponges & Cnidarians

Sponges

Osculum-

Collar Cells-

Spicules-

Pore-

Archeocyte-

Larva(e) -

Filter feeder-

Internal Fertilization-

No tissues-

Asymmetrical-

Cnidarians

Have tissues-

Radial Symmetry-

Cnidocytes- cnidarian stinging cells

Nematocyst- tube, poison, & barbs

Gastrovascular cavity-

Tentacles-

Mouth/anus-

Nerve net-

Polyp-

Medusa-