Ch 27 Summary

heterotrophy

mobility

multicellularity

sexual reproduction

diploidy

the absence of a cell wall

blastula formation

cells organized as tissues

Radial symmetry- have body parts arranges around a central axis

Bilateral symmetry- distinct right and left half, and most display cephalization

Three basic body plans

Acoelomate- no body cavity

Pseudocoelomate- body cavity located between the mesoderm and endoderm

Coelomate- [true coelom] body cavity located entirely within the mesoderm

Segmentation in body structure underlies the organization of all advanced animals

There are about 35 animal phyla, which contain an extraordinary range of body forms and body systems

Scientists classify animals using several different types of data, which include comparing anatomy and physiology, patterns of development, and DNA.

The animal kingdom is divided into two groups: vertebrates and invertebrates

Body systems are specialized to carry out different tasks

Simple animals have a gastrovascular cavity with only one opening, while more complex animals have a one-way gut

Simple animals exchange gases directly through their skin

More complex aquatic animals use gills, while terrestrial animals use a a variety of respiratory organs (such as lungs)

Open circulatory system- circulatory fluid leaves the vessels and enters the body cavity

Closed circulatory system- blood remains in vessels

Simple animals have little coordination among their nerve cells

Complex animals have nerve cords and a brain with associated sensory structures

For most animals eliminating wastes is linked to maintaining the correct water balance in their body

Asexual reproductive methods- fragmentation, splitting in two, and parthenogenisis

Sexual reproduction- male and female gametes combine to form a new individual