what must a mc organism do? #8 Flashcards
cell
basic structural and functional unit of life
tissue
ensemble of similar cells that together carry out a specific function
differentiation
cell or tissue specialization
adhesion
cells interact and adhere with neighboring cells
morphology
form and structure of organisms
what are the eukaryotic groups containing complex mc & how many times did they evolved?
green algae/ land plants (several times)
animals (1)
brown algae (1)
fungi (3)
red algae (multiple times)
similarities of simple & complex mc
- reproductive & somatic cells
- adhesive molecules to
maintain unified structure
differences of simple mc
- limited signaling & sharing of resources between cells
- usually all cells are in direct contact w/ surrounding environment
differences of complex mc
- complex cell differentiation
- organized signaling and
resource sharing - tissue differentiating (specialized tissues) * programmed cell death
what is the definition of diffusion?
substance more from areas of high concentration/ pressure to low concentration/ pressure
how does diffusion place constrains on organism size
if 02 is taken in only simple diffusion - size is limited by ambient p02 is a few mm thick
how does simple organism transport oxygen?
simple diffusion
how does complex organism transport oxygen
coordinated movements of flagella to move water
what are the 2 basic requirements for mc ?
cell adhesion & cell communication
cell adhesion
- forms a “unit” out of more than one cell
- formation of coherent & reprovable morphology
cell communication
- leading to coordinated activity between cells
- all cells have transmembrane proteins that mediate signals from environment
- complex mc organism also posses microscopic passages across cell walls/ membranes
what are the 3 kinds of cell- cell junctions in animals
tight junction - % leakage
gap junction - direct chemical communication
anchoring - adherens (actin filaments) junctions/ desmosomes (intermediate filaments)
what is the cell- cell junction in plants
plasmodesma
what is a program of development
genetic program with well- defined molecular signaling networks
coordinated across time & space
why is it necessary for p.o.d for complex mc
bc plants & animals need
4 reasons why eukaryotic cells is important for the evolution of complex mc
- prokaryotes have a single circular chromosome
- much faster than diffusion alone
- opens up possibilities for size, structure , function, development
- 2 processes critical to the development of mc organisms
