Transcript Introduction to Animals

Introduction to Animals
Heterotrophs
2.
Multicellular
3.
Most are Mobile
4.
Most reproduce sexually/ few can asexually reproduce
5.
No cell wall
6.
Most (except sponges) have tissues. These are groups of cells that work
together to perform a specific function. Ex: nerve tissue sends/receives signals
7.
Formation of a Blastula (except sponges): a zygote that has gone through cell
division until a ball of cells is formed. This ball of cells (blastula) keeps
dividing until 3 distinct layers form. These layers will form into tissues and
organs in the adult body.
a. ectoderm: outer-layer- outer layer of skin, nervous system, sense organs
b. endoderm: inner-layer- lining of digestive tract, respiratory system, urinary
bladder, digestive organs such as liver, and many other glands.
c. Mesoderm: Separates inner and outer layer- Most of the skeleton,
muslcles, circulatory system, reproductive organs, and excretory organs.
8. atoms, molecules, cells, tissues, organs, organ systems, organism
1.
Body Symmetry
A.
Three types of symmetry: body shape
1. Asymetrical: no specific shape/irregular
(Sponges, coral)
2. Radial symmetry: body parts are arranged around a central axis, like
spokes around a bicycle wheel. (Phylums Cnidarian, Echinodermata)
These organisms resemble a pie where several
cutting planes produce roughly identical
pieces. An organism with radial symmetry
exhibits no left or right sides.
3.
Bilateral symmetry
a. Have distinct right and left halves. A plane passing through the animal’s
midline divides the animal into mirror image halves.
The elaborate patterns on the
wings of butterflies are one
example of biological symmetry.
Dissection/Position Terms
Dorsal: The back of an organism
Ventral: Stomach area
Medial: middle
Lateral: Side
Anterior: Towards the head
Posterior: Towards the back end or rear end area
Caudal: tail
Cranial: Head
Posterior: hind end
Medial
Anterior: front end
Lateral