BIOL112 SI- Session 23- Ch. 33

Choanoflagellates are considered to be a ____ of animals in a phylogenetic tree.

• sister taxa

• basal taxa

• node

• ancestor

The gastrula contains all of the following except ____.

• a blastopore

• a blastocoel

• an archenteron

• a cross section

A coelom can form in both diploblastic and triploblastic animals.

• True

• False

The biggest extinction event occurred around ____.

• 450 MYA

• 400 MYA

• 250 MYA

• 200 MYA

• 50 MYA

The ectoderm becomes the ____, and the endoderm becomes the ____.

• outer covering, muscles and bones and blood

• muscles and bones and blood, outer covering

• outer covering, digestive tract and internal organs

• muscles and bones and blood, digestive tract and internal organs

The ____ tissues comprise the brain and spinal cord.

• epithelial

• connective

• muscle

• nervous

Which is not true of glial cells?

• They are neurons specialized to receive electrical impulses.

• They include astrocytes.

• They transmit electrical transmits.

• They include axons.

Connective tissues offer support, while epithelial tissues are classified by numbers of layers and shapes of cell.

• True

• False

Which is NOT true of specialized intercalated discs?

• They join adjacent cells.

• They are involved with neurotransmitters.

• They pass electrical impulses?

• They work in conjunction with muscle tissues.

This process results in the conservation of heat.

• Vasoconstriction

• Countercurrent exchange

• Striations

• Synapse