Acritarchs are microfossils of green microalgae thereby providing fossil evidence that eukaryotes originated by a least 2.0 Ga.

The oldest definitive body fossils of metazoan animals are from the:

Sponges (phylum Porifera) are multi-cellular animals that lack true tissue-grade organization to their bodies.

Retention of ancestral juvenile features into the adult stages of its descendant is called: 

Name the two muscles “A” and “B” in the posterior leg. (2 points each) Both of these muscles insert on to what bone via the Achilles tendon? (1 point)

Identify each myofilament. (1 point each) A.B.C.D.

Determine what actions were done to assume this position AND what muscles were used to create those actions.  One action and muscle are required at each joint location.  (2 points per joint; 16 points total) Action @ the Joint Muscle that Contracted to Create that Action a. head @ neck:   b. spine @ torso:   c. scapula:   d. arm @ shoulder:   e. forearm @ elbow:   f. thigh @ hip:   g. leg @ knee:   h. foot @ ankle:  

What do the temporalis and masseter muscles have in common?

All of the following muscles contribute to the rotator cuff except…

A. What happens to the length of a sarcomere during skeletal muscle contraction?  (1 point)   B. Describe the events of cross-bridge cycling that lead to this change; citing specific structures (myofilaments, events, sequences).  Elaborate on your answer in complete sentences.  (4points)