BIO 242 EXAM 3 EXAM SCRIPT 2026
COMPLETE QUESTIONS AND VERIFIED
ANSWERS
⩥ Hox genes. Answer: series of genes that controls the differentiation of
cells and tissues in an embryo
⩥ Tissues. Answer: Groups of cells that are similar in structure and
function
⩥ Eumetazoa. Answer: clade of animals with true tissues e.g. all animals
except proferia (sponges)
⩥ Diploblastic animals. Answer: Have only two germ layers, the
ectoderm and the endoderm, and lack true digestive system.
⩥ Triploblastic animals. Answer: Have three germ layers: ectoderm,
mesoderm (gives rise to muscles and organs), endoderm.
⩥ body cavity. Answer: Cushion the suspended organs, fluid in the body
cavity act as skeleton for support, internal organs can grow and move
independently of outer body wall.
, ⩥ coelom. Answer: fluid-filled body cavity lined with mesoderm
⩥ hemocoel. Answer: The primary body cavity of most invertebrates,
containing circulatory fluid. Develops between mesodermal and
endoderm
⩥ Bilateria. Answer: Members of the branch of eumetazoans possessing
bilateral symmetry.
⩥ Cambrian explosion. Answer: A burst of evolutionary origins when
most of the major body plans of animals appeared in a relatively brief
time in geologic history; recorded in the fossil record about 545 to 525
million years ago.
⩥ How many phyla are in the animal kingdom?. Answer: 32-33. Tell this
by hox genes, rrna, proteins, mitochondria genes, morphological
differences
⩥ Sister group to all other animals. Answer: sponges
⩥ 3 major classes of bilaterian animals. Answer: Deuterostimia, lophor
⩥ Deuterostomes. Answer: Animals in which the blastopore becomes the
anus during early embryonic development. Eg. Acorn worms
COMPLETE QUESTIONS AND VERIFIED
ANSWERS
⩥ Hox genes. Answer: series of genes that controls the differentiation of
cells and tissues in an embryo
⩥ Tissues. Answer: Groups of cells that are similar in structure and
function
⩥ Eumetazoa. Answer: clade of animals with true tissues e.g. all animals
except proferia (sponges)
⩥ Diploblastic animals. Answer: Have only two germ layers, the
ectoderm and the endoderm, and lack true digestive system.
⩥ Triploblastic animals. Answer: Have three germ layers: ectoderm,
mesoderm (gives rise to muscles and organs), endoderm.
⩥ body cavity. Answer: Cushion the suspended organs, fluid in the body
cavity act as skeleton for support, internal organs can grow and move
independently of outer body wall.
, ⩥ coelom. Answer: fluid-filled body cavity lined with mesoderm
⩥ hemocoel. Answer: The primary body cavity of most invertebrates,
containing circulatory fluid. Develops between mesodermal and
endoderm
⩥ Bilateria. Answer: Members of the branch of eumetazoans possessing
bilateral symmetry.
⩥ Cambrian explosion. Answer: A burst of evolutionary origins when
most of the major body plans of animals appeared in a relatively brief
time in geologic history; recorded in the fossil record about 545 to 525
million years ago.
⩥ How many phyla are in the animal kingdom?. Answer: 32-33. Tell this
by hox genes, rrna, proteins, mitochondria genes, morphological
differences
⩥ Sister group to all other animals. Answer: sponges
⩥ 3 major classes of bilaterian animals. Answer: Deuterostimia, lophor
⩥ Deuterostomes. Answer: Animals in which the blastopore becomes the
anus during early embryonic development. Eg. Acorn worms
