Lecture 1 Flashcards
What are the qualities that make an animal animal
- mobile
- heterotrophics
- reproduce (usually sexually)
- multicellular
- abscence of cell wall
single-celled eukaryotes
protozoans
animal cell that have other cell covering other than the cell membrane
egg cell
animals that have no vertabral column (backbone)
invertebrates
percentage of invertebrates
97% our of 7.8 million animal species
what is the vertebral column for
structural support
structural support of invertebrates
- exoskeleton
- hydrostatic skeleton
How many phyla are there
36
group of individuals able to form a viable offspring
species
groups of multicellular animals
Metazoa
- cells are arranged in tissues
- true tissues
eumetazoa
Two group divisions under eumetazoa
- radiata
- bilateria
animals that can be divided into several identical halves when cut along the central axis
radiata
animals that can be divided into two identical halves along a single axis
bilateria
Two divisions under bilateria
- Deuterostomia
- Protostomia
first opening in the embryo becomes the mouth
protostomes
first opening in the embryo becomes the anus, and the mouth develops later
deuterostomes
What are the basis of groupings of the Kingdom Animalia?
- levels of organization
- symmetry
- coelom
- segmentation
- body plan
levels of organization
- metazoa
- eumetazoa
What is the difference between phylum Porifera and other phyla?
- conglomerate of cells
- no true tissues
- loose aggregation of different cells
Symmetry
- Radial
- Bilateral
- Asymmetrical
central axis
radial
left side and right side are mirror images of each other
bilateral
having parts that fail to correspond to one another in terms of shape and size
asymmetrical
coelom
- acoelomate
- coelomate
- pseudocoelomate
- These organisms, like flatworms, do not have a body cavity
- Their space between the body wall and the digestive tract is filled with tissues. :
Acoelomates
- These organisms, like roundworms, have a body cavity which is not completely lined by mesoderm.
- It is between the endoderm and the mesoderm.
Pseudocoelomates
- These organisms, like humans, have a body cavity called a coelom that is completely lined by mesoderm.
- The coelom is between the body wall and the digestive tract.
Coelomates
condition of being constructed of a linear series of repeating parts, each being a metamere (body segment, or somite) and each being formed in sequence in the embryo, from anterior to posterior
segmentation
refers to a body plan wherein the body contains a cluster or aggregation of cells that are not organized into cells or organs. The phylum porifera’s members have this body plan. Sponges are the generic term for these.
cell aggregate plan
Different animal body plan
- Cell aggregate plan
- Blind-sac plan
- Tube-within-a-tube plan
Phylum that have a cell aggregate body plan
Phylum Porifera
Parts of a sponge
- osculum
- pinacoderm
- mesohyl layer
- choanoderm
- ostia
- spongocoel
large aperture in a sponge through which water is expelled
osculum
forms an external barrier on the surface and canals of sponges to protect it from the outer environment.
pinacoderm
- gelatinous matrix that is filled in the space between the external outermost layer called pinacoderm and the internal layer called choanoderm
- composed of collagen, galectin, and other elements.
Mesohyl layer
- formed by the joining of choanocytes join together
- create a flow of water
- capture food items as they pass by these cells
- flow of water is initiated through the coordinated beating of flagella
choanoderm
What forms the choanoderm
choanocytes
- minuscule pores present on the body walls of sponges
- formed by porocytes which are tube-shaped cells that function as valves to allow fluid exchange.
Ostia
central cavity of the sponge
spongocoel
What forms the ostia
porocytes
