Metazoa Flashcards
Metazoa
Animals
Characteristic of Metazoa all metazoans
Multi-cellularity
Eat food
Define: Polytomy
Multiple branches from 1 ancestor species
What do thick lines represent on a phylogeny
A fossil record
Define: Lysotroph
Food is broken down outside of body and absorbed. (Human digestion is considered out side of body)
Define: Phagotroph
digestion inside of body
Define: Analogous
Traits not inherited from common ancestor but evolved separately.
Characteristics of most metazoans
Sexual life cycle = diploid
Differentiated tissues
Gastrulation of embryo
T/F multicellularity evolved independently
True
What is the origin of multicellularity
Colonies
What is the closest single cell relative of Metazoans
Choanoflagellates
What is distinct about choanoflagellates
Sperm shaped w. similar flagella
T/F the common ancestor of Fungi and metazoans was unicellular
True
What are important genes for multicellularity
Cell signaling
Adhesion
Gene regulation
ECM - Makes proteins for tissues
What organism is similar to the the cell found on the posterior of a sponge
Choanoflagellates
What defines Cambrian Explosion
Explosion of speciation
What are important structures for organisms in the Cambrian explosion
Locomotion
Shells
Teeth
When did the first animals appear
during the Ediacarian period.
What features are used to classify animals?
Symmetry
True tissue
body cavity
Development - Gastrulation
What developed first?
Multicellularity or Adhesion and cell signaling
Adhesion and cell signaling
What is the haploid stage in humans
Sperm or egg
What defines bilateral symmetry
One axis of symmetry
What defines radial symetry
Multiple lines of symetry
What classifies a true tissue
Specialized and separated by a membrane
Which animal does not have true tissue
Sponges
What are the types of tissue
Connective
Epithelial (skin - organ covering)
muscle
nervous
4 Ways to identify body plan
Type of Symmetry
True tissue
Body cavity and formation
Development
Why aren’t simmilar body plans always resembled in clades
Because of molecular data in phylogenetics
Define Diploblastic
ectoderm
endoderm
Define triploblastic
Ectoderm
endoderm
mesoderm
Define a body cavity
space between organs
What is a true body cavity
Coelom
What is a puesdocoelom
a body cavity derived from mesoderm and endoderm
What is the difference between coelom and puesdocoelom
Mesoderm is the only thing that touches the coelom in a a true body cavity.
A puesdocoelom has endoderm and mesoderm touching the cavity.
What is gastrulation
Early embrionic development
Forming a tube from a sphere
What are two distinct types of gastrulation
Radial Cleavage
Spiral Cleavage
T/F Cells in spiral cleavage can separate and form other organisms
False
Cells cannot separate in spiral cleavage
When can cells totally differentiate?
Before the 8 cell stage
What do the cells differentiate to in the 8 cell stage
Endoderm
mesoderm
ectoderm
What forms first in protostomes
Mouth
What forms first in deuterostomes
Anus
T/F humans are dueterosomes
True
What does it mean that sponges are Basal animals
They are at the “base”
ancient animals
Not basic
What is a major clade for most animals
Bilaterians
T/F dueterstomia is a major clade for choradtes and other animals
True
Define: Hox Genes
Genes that regulate body formation
How do hox genes affect growth.
Through inhibiting transcription.
