Animals in the Tree of Life

Question 1

A species name is binomial—having two parts:

Answer 1

a genus and a species epithet

Question 2

All organisms stem from a universal common ancestor at the root of the tree of life*. From this common ancestor, scientists (especially, evolutionary biologists) were able to identify three broad categories of organisms called

Answer 2

Domains

Question 3

Three Domains in the Tree of Life

Answer 3

Bacteria, Archaea, and Eukarya

Question 4

What is the difference between the three domains in the tree of life?

Answer 4

Bacteria and Archaea are prokaryotes, which are single-celled organisms whose DNA is not enclosed in a membrane. The domain Eukarya (i.e. eukaryotes), however, has eukaryotic cells which are structurally more complex than prokaryotes. Eukaryotic cells have a nucleus – whose DNA is enclosed in a membrane, and membrane-bound organelles in order to perform many cellular functions. Membrane-bound organelles are compartmentalized structures that are able to perform more specific cellular processes. Some of these organelles have even originated from prokaryotic cells!

Question 5

Animals are ???, which basically mean that they eat other organisms, breaking them down using digestive juices in their gut.

Answer 5

heterotrophs

Question 6

Structurally, animals are ???, ???, and have organs born from ???.

Answer 6

Multicellular
Without Cell Walls
Born from Three Embryonic Tissues, the Ectoderm, Mesoderm, and Endoderm

Question 7

completely surrounds the body of the animal

Answer 7

ectoderm

Question 8

surrounds its digestive tract

Answer 8

endoderm