Midterm Flashcards
Definition of anterior
near the front
Definition of posterior
near the back
Definition of dorsal
upper side or back of an animal
Definition of ventral
underside of an animal (abdominal)
Definition of medial
near the median plane of the body/organ
Definition of lateral
region furthest from the median plane
Definition of distal
away from the center of the body or point of attachment
Definition of proximal
near center of the body or point of attachment
Definition of sagittal
plane dividing the body into left and right
Definition of common descent
coming from the same ancestors
Definition of reproductive community
a community that reproduces together
Definition of cosmopolitan
what percent of animals do we know?
20% of all animals alive right now
1% of all animals ever
what are species?
consists of populations that share the same traits and can interbreed (usually)
what is protoplasmic organization?
-all functions occur in one cell (single celled organisms)
-have organelles for different functions
some problems with protoplasmic organization
-limits effectiveness of cell
-cells cannot work together
cellular grade of organization
-cells are specialized
-individual cells cannot live on its own
-work is divided among cells
-no tissue
cell-tissue grade of organization
-specialized cells grouped together as a unit to preform a function (tissue)
-preform one common function
tissue-organ grade of organization
-tissue is grouped as a unit for a common function (organ)
organ-system grade of organization
-organs working together for a common function
-highest level of organization (specialized organs)
what is spherical symmetry?
-usually single cell
-beach ball shape
-any plane through the body with create symmetry
-good for floating and rolling
what is radial symmetry?
-circular shape
-“jellyfish pizza”
-more than 2 planes through center create symmetry
what is biradial symmetry?
-special form of radial symmetry
-only 2 planes produce mirrored halves (oval)
what is bilateral symmetry?
-right and left mirror halves along the sagittal plane
- great for forward movement
-head and tail region
what are germ layers?
-distinct layers of cells that develop shortly after fusion of sex cells
-all tissues and organs develop from these
what is the body cavity?
-also known as the coelom
-internal space
-blastopore from germ layer becomes mouth and anus
-three types: acoelomate, pseudocoelomate, eucoelomate
what is a taxon?
common term for any rank in taxonomy
how was taxonomy originally created?
-organized by morphological traits; morphology, movement, respiration, reproduction
-no consideration for evolution
modern taxonomy
-better understanding of evolution
-genetic sequencing
-physical traits are the result of genetic information (inherited from ancestors)
-reproductive communities have genetic cohesiveness (from interbreeding)
-focus shifted from classifying living animals to grouping by ancestry
what is a clade?
a group of organisms hypothesized to have evolved from a common ancestor
advantages of creating trees
-precise pattern of evolutionary changes that led to animals current features
-make predictions about fossils
-make predictions about poorly studied animals
definition of sessile
-proifera adults that are attached to a surface
definition of choanoflagellates
-cells inside porifera that have flagella and move water upwards
definition of placozoa
definition of osculum
-exit hole of porifera
definition of spicule
-hard structures in the mesohyle made of calcerous or siliceous materials
-adds rigidity
definition of mesohyle
-jelly-like matrix made of collagen and spicules
definition of spongin
-specialized form of collagen
definition of calcareous
-CaCO3 (makes up spicules)
definition of siliceous
-silica (makes up spicules)
definition of monoecious
-produce both male and female gametes
definition of parenchymula
-ciliated larvae from porifera sexual reproduction
what are porifera?
sponges
where are porifera found?
-salt or fresh water (mostly salt)
-shallow or deep water
-attached to a surface
what do porifera do?
-provide shelter and food for other animals
-filter food particles from the water (sponge loop- saprozoic feeding)