TAMU Bio 112 Chapter 27 and 33
Questions and Answers.
when was the most recent common ancestor of animals and sponges - Answer 770 MYA
when was the common ancestor of fungi and animals - Answer 1 BYA
what is the closest living relative of animals - Answer choanoflagellates (protists)
what are choanoflagellates - Answer small unicellular protists
how did animals evolve - Answer evolved into multicellular
differentiated cells, tissues, organs, organ systems
what are cadherins - Answer genes that encode proteins involved in cell-signaling and
attachmnet
what forms the gastrula stage (with blastopore and archenteron) - Answer gastrulation
what created the germ layers (origins of tissues) - Answer gastrulation
what are formed first and then second - Answer endoderm and ectoderm form first
then mesoderm forms later between them
what do hox genes do - Answer determine body plan, segmentation, number and placement
Hox gene characteristics - Answer highly conserved genes
encode transcription factors (proteins)
determine course of embryonic development
Hox-A, Hox-B, Hox-C, Hox-D
genes within the clusters are expressed in certain body segments at certain stages of
development
what are body plans - Answer general structure of an animal the arrangement of its organ
systems, and the integrated functioning of its parts
, what are the body plan features - Answer symmetry
body cavities
segmentation
presence and function of appendages
symmetry - Answer most animals are symmetric
Radial Symmetry - Answer arrangement of body parts around a central axis
sessile (attached) life
planktonic (drifting) life
There is a top and bottom
no right or left side nor front or back
bilateral symmetry - Answer has two axes of orientation: front to back and top to bottom
usually has a head
active lifestyle
how many germ layers do most animals have - Answer 2 or 3 germ layers
diploblastic - Answer with 2 germ layers
ectoderm gives rise to outer covering and nerves
endoderm is digestive tract, internal organs
triploblastic - Answer 3 germ layers
mesoderm- muscles bones, blood
develops between ectoderm and endoderm
what is the body cavity called and where is it derrived - Answer it is called the Coelom and
derived from the mesoderm
what is the coelom - Answer fluid-filled space between body wall and gut
what are most body cavities - Answer true coeloms
formed from the mesoderm
Questions and Answers.
when was the most recent common ancestor of animals and sponges - Answer 770 MYA
when was the common ancestor of fungi and animals - Answer 1 BYA
what is the closest living relative of animals - Answer choanoflagellates (protists)
what are choanoflagellates - Answer small unicellular protists
how did animals evolve - Answer evolved into multicellular
differentiated cells, tissues, organs, organ systems
what are cadherins - Answer genes that encode proteins involved in cell-signaling and
attachmnet
what forms the gastrula stage (with blastopore and archenteron) - Answer gastrulation
what created the germ layers (origins of tissues) - Answer gastrulation
what are formed first and then second - Answer endoderm and ectoderm form first
then mesoderm forms later between them
what do hox genes do - Answer determine body plan, segmentation, number and placement
Hox gene characteristics - Answer highly conserved genes
encode transcription factors (proteins)
determine course of embryonic development
Hox-A, Hox-B, Hox-C, Hox-D
genes within the clusters are expressed in certain body segments at certain stages of
development
what are body plans - Answer general structure of an animal the arrangement of its organ
systems, and the integrated functioning of its parts
, what are the body plan features - Answer symmetry
body cavities
segmentation
presence and function of appendages
symmetry - Answer most animals are symmetric
Radial Symmetry - Answer arrangement of body parts around a central axis
sessile (attached) life
planktonic (drifting) life
There is a top and bottom
no right or left side nor front or back
bilateral symmetry - Answer has two axes of orientation: front to back and top to bottom
usually has a head
active lifestyle
how many germ layers do most animals have - Answer 2 or 3 germ layers
diploblastic - Answer with 2 germ layers
ectoderm gives rise to outer covering and nerves
endoderm is digestive tract, internal organs
triploblastic - Answer 3 germ layers
mesoderm- muscles bones, blood
develops between ectoderm and endoderm
what is the body cavity called and where is it derrived - Answer it is called the Coelom and
derived from the mesoderm
what is the coelom - Answer fluid-filled space between body wall and gut
what are most body cavities - Answer true coeloms
formed from the mesoderm
