Chapter 32

• animals


  A very diverse group that share major characteristics: heterotrophs, multicellular, no cells walls, able to move, and much diversity of form and size.
• Do animals reproduce sexually or asexually?

  sexually
• embryonic development


  Animals have a characteristic pattern of ___.
• tissues


  What are the cells of all animals (besides sponges) organized into?
• symmetry, tissues, body cavity, patterns of development, segmentation


  What are the five key innovations in animal evolution.
• Sponges


  These lack symmetry and are therefore asymmetric.
• Eumatazoans


  Animals that have symmetry defined along an imaginary axis drawn through the body.
• radial


  The type of symmetry in which the body parts are arranged around a central axis.
• radially symmetric


  These types of animals can be bisected into two equal halves in any 2-D plane that passes through the center.
• bilateral


  The type of symmetry in which the body has right and left halves that are mirror images.
• cephalization and greater mobility


  What are the two advantages that bilaterally symmetric animals have over radially symmetric animals?
• cephalization


  The evolution of a brain area.
• Parazoa (sponges)


  Lack defined tissues and organs and have the ability to disaggregate and reagregate cells.
• Eumatozoa


  All animals that have well-defined tissues and irreversible differentation for most cell types.
• zygotes


  Fertilized eggs that are totipotent and develop into all other body cells.
• 3


  How many germ layers do most eumatozoans produce (except Cnidarians)?
• ectoderm, mesoderm, endoderm


  Most eumatozoans produce three germ layers. What are they?
• mesoderm


  The middle germ layer that develops into the skeleton and muscles.
• ectoderm


  The outer germ layer that develops into body coverings and the nervous system.
• endoderm


  The inner germ layer that develops into digestive organs and intestines.
• blue


  In most pictures and diagrams, what color represents the ectoderm?
• red


  In most pictures and diagrams, what color represents the mesoderm?
• yellow


  In most pictures and diagrams, what color represents the endoderm?
• body cavity


  The space surrounded by the mesoderm that is formed during development.
• acoelomate


  an animal that lacks a coelom, or body cavity
• pseudocoelomate


  The body cavity that found between the mesoderm and endoderm.
• coelomate


  The body cavity that is entirely within the mesoderm.
• acoelomate


  What type of body cavity is shown in this photo?

  
• pseudocoelomate


  What type of body cavity is shown in this photo?

  
• coelomate


  Which type of body cavity is shown in this photo?

  
• body cavity


  What made the development of advanced organ systems possible?
• circulatory system


  What did coelomates develop for the flow of nutrients and the removal of wastes?
• open circulatory system


  Type of circulatory system in which blood passes from the vessels into the sinuses and mixes with body fluids and reenters vessels.
• closed circulatory system


  Type of circulatory system in which blood moves continuously through vessels that are separated from body fluids.
• Blastula


  Hollow balls of cells that are formed from mitotic cell divisions in the embryo.
• blastopore and archenteron


  Blastula indents to form a two layer thick ball with what two things?
• blastopore


  The opening of the central cavity of an embryo in the early stage of development.
• archenteron


  The primitive body cavity of an embryo.
• protostomes, deuterostomes


  What are the two groups that bilaterians can be divided into?
• protostomes


  Animals that develop mouth first from or the near blastopore.