Animals that possess homologous structures probably :

 The common ancestor shared by mouse and gorilla is at point ______ on the phylogeny shown.

Formation of a distinct head is called 

The very broad field of study of animals is

After a sperm fertilizes an egg, the zygote undergoes

An organism that utilizes extracellular enzymes to digest and absorb food, multi-cellular and single-celled life cycle, and non-photosynthetic describes

Intracellular digestion occurs

reflect the hierarchical classification of taxonomic groups nested within more inclusive groups.

Archaea, Eukarya, Bacteria are the three types of _____________ that encompass all living things.

Organisms with the simplest tissue level of organization are