chapter 32 animal diversity[1]
TRANSCRIPT
Chapter 32: An Introduction to Animal Diversity
Hannah Love12/01/2011p. 654
Nutritional Mode
Animals are heterotrophs Heterotrophs: relies on other
organisms for food (as opposed to autotrophs)
Cell Structure and Specialization Eukaryotes: Organisms that carry genetic
material (DNA) in the form of chromosomes within a distinct nucleus
Multicellular: Made of multiple cells
Animal cells have no cell walls Held together by structural proteins (like collagen)
Muscle and nerve cells are unique to animals
Reproduction and Development
Cleavage: a succession of mitotic cell divisions
Reproduction and Development Most animals reproduce sexually
Some animals develop directly into adults through transient stages of maturation Like humans
Metamorphosis: Developmental transition that turns the animal into a juvenile Juvenile: resembles an adult, but not entirely
sexually mature
The History of Animals
Neoproterozoic Era 1 Billion – 542 Million Years Ago Ediacaran biota: Early eukaryotic
bacteria
Paleozoic era 542-251 Million Years Ago Cambrian Explosion: dramatic
explosion in the growth of animal diversity (535-525 million years ago)
The History of Animals
Mesozoic era 251-65.5 Million Years Ago Animals began to spread into new habitats First dinosaurs and mammals
Cenozoic era 65.5 Million Years Ago – Present Began with mass extinctions Mammals rise
Symmetry
Radial Symmetry: has no left and right side, any “imaginary slice” creates mirror images
Bilateral Symmetry: only one “imaginary slice” can divide this into two mirror image sides – right and left
Tissues
Tissues: integrated group of cells with a common function Maintain
organization within the animal’s body
Body Cavities
Body cavity: fluid- or air-filled space
Protostome and Deuterostome Development
Phylogeny and Molecular Data
Phylogeny: history of organism lineages as they change through time
New views of animal phylogeny are emerging from molecular data