Animals Unit Flashcards
what characteristics do all animals share?
- multicellular
- eukaryotic (no cell walls)
- motil
- heterotrophic
what is the difference between complete and incomplete metamorphosis?
complete metamorphosis:
- body changes completely
incomplete metamorphosis:
- not much change
what is bilateral symmetry?
when something is divided by a line that separates the halves into nearly identical halves.
what is radial symmetry?
when the body plan is divisible into identical parts around a central axis
what is asymmetrical symmetry?
lack of symmetry.
what are the three germ layers, where they’re located and what do they form?
ectoderm- forms outer layer of body (skin, nails, feathers, etc; think exterior)
mesoderm- forms middle layer (body systems; think M for middle)
endoderm- forms inner layer of body (stomach lining; think interior)
what is the difference between diploplast and triploplast?
diploplast has two germ layers wherears triploplast has three
what are the two body plans and how are they different?
complete- mouth and anus are different openings, allows for specialization
sac plan- mouth and anus are the same opening; no specialization
what is coelom?
fluid-filled cavity located between gut and body; is also where all internal organs are found
acoelomate (no body cavity)
what is the difference between protosome and deuterostome?
protosome: blastopore is first opening
deuterostome: anus is first opening
list the main characteristics of sponges:
- sac-like bodies with many pores
- sessile
- filter feeds
- monoecious
- cellular level of organization (no tissue)
function of choanocytes
flagellated collar cells used for feeding
function of epidermal cells
cells forming the outer layer of the animal
function of spicules
rods of silica/spongin/carbonate of used for support
function of amoebocytes
amoeba-like cells that transport food and make “skeletal elements”
what material can spicules be made from?
silica, calcium, and protein
how does the sponge obtain food?
strained by the collar and transported down, cells absorb food by endocytosis. cell either digests it or exocytoses it and another cell takes it
what is the amoeboid responsible for?
- circulates nutrients through sponges
- makes gametes and spicules (internal skeleton)
what are gemmules?
- sphere-shaped collection of amebocytes surrounded by a tough layer of spicules
- can exist for a very long time
what is a cnidocyte? how do they work?
definition: stinging cell
- has a capsule called nematocyst which contains a long, coiled thread
- filled with paralyzing toxins
- nematocysts discharged when triggered
how is sexual reproduction different between a hydra and a jellyfish (medusa + polyp)?
- medusa produces sperm and egg into the water
- hydra develops ovaries/testes in the body wall
how is asexual reproduction done?
fragmentation
cnidarians are able to move because they have muscle fibers, they can also do movements like ________ and ________.
expanding + shrinking
cnidarians don’t have a brain but have a…?
nerve net
medusa have specialized cells. what are their names and their functions?
a. statocysts (for balance + for staying upright)
b. ocelli (eyespot, detect light)
which body plan has only one opening?
sac-like body plan. it’s used to obtain food as well as get rid of undigested material.
which body plan has a separate mouth and anus, and why is it more effective than sac-like?
one-way system. it’s more effective because it is often specialized into organs, making it much more efficient,
do motile animals tend to be bilaterally symmetrical, radially symmetrical, or asymmetrical?
bilaterally symmetrical
define “hermaphrody”.
an organism specialized in both male and female reproductive organs, producing both sperm and ova.
true or false: acoelomates have coeloms.
false, they do not have coeloms.
how is an individual identified as an acoelomate? (what “parts” do they have?)
- ectoderm
- mesoderm
- endoderm
- digestive cavity
how is an individual identified as a eucoelomate? (what “parts” do they have?)
- ectoderm
- mesoderm
- endoderm
- COELOM
how is an individual identified as a pseudosoelomate? (what “parts” do they have?)
- ectoderm
- mesoderm
- endoderm
- pseudocoelom
which germ layers do acoelomate, eucoelomate and pseudocoelomate all have in common?
- ectoderm
- mesoderm
- endoderm
what are some characteristics of flatworms?
- acoelomates
- two forms: free-living + parasitic
what are some characteristics of nematodes (roundworms)?
- pseudocoelomate
- two forms: free-living + parasitic
what are some characteristics of flatworms?
- eucoelomate
- two forms: free-living + parasitic
