Animal Architecture — Body Plans, Development, and Tissues

Flashcards covering key terms and concepts regarding animal characteristics, levels of organization, body symmetry, germ layers, developmental stages, and body components from the lecture notes.

What are the general characteristic that defined an animal?

Animals are eukaryotic, multicellular, heterotrophic organisms with no cell wall. They are diploid, usually reproduce sexually, undergo embryonic development, and may have a larval stage.

Comparing contrast the protoplasmic, cellular, tissue organ, and organ system level of organization in animals

• Protoplasmic = one cell does everything

• Cellular = multiple cells; cells work together and accomplish functions, but they are not yet organized into true tissues.

• Tissue = cells working together; The cells in a tissue work together to perform a common function

• Organ = tissues working together; brain is an organ because it contains multiple tissue types that work together to perform the functions of the brain.

• Organ system = multiple organs working together, the nervous system includes organs and structures such as the brain and spinal cord that work together.

Discuss the three types of body symmetry seen in animals

1. Asymmetry

2. Radial symmetry

3. Bilateral symmetry

asymmetry

Asymmetry means there is no plane or line through which the body can be divided into equal halves.

Example: Sponges

Radical symmetry

animal can be divided into similar or mirror-image portions by multiple planes passing through its longitudinal axis.

examples:

starfish jellyfish, coral sea urchins, sea anemones

What are the advantages and disadvantages of radial symmetry?

• Have no distinct anterior (front) or posterior (back) end

• Can interact with their environment in all directions

• Are often sessile, freely floating, or weakly swimming

Examples: Cnidaria and Ctenophora.

What is bilateral symmetry?

an animal can be divided into mirror-image right and left halves by only one sagittal plane.
➡ One cut down the middle = two mirror-image sides.

Examples include:

• Butterflies

• Ladybugs

• Bees

• Beetles

• Most insects

Gastrulation

The developmental process following the blastula stage during which embryonic germ layers are established.

Eukaryote

An organism composed of one or more cells containing a membrane-bound nucleus and specialized organelles.

Prokaryote

A single-celled organism that lacks a membrane-bound nucleus and membrane-bound organelles.

Tissues

Groups of similar cells specialized to perform a common function, four major types of which form during embryonic development.