Chapter 26.1- 26.2 Flashcards
How do eukaryotes show simple multicellularity??
- filaments
- hollow balls
- sheets of little differentiated cells
Components of a simple multicellularity
- Cell adhesion: uses adjacent molecules to stick together
- a full range of functions: in case the cell dies
- direct contact with the environment
advantages of multicellularity organisms?
- One selective helps organisms avoid getting eaten.
- able maintain the same position
- flagella helps direct food to the cell
Disadvantages of multicellularity?
- cancer can be a result of cells non cooperating because cells use nutrition for personal cell and not for the growth of organism
Complex multicellular organisms share three main functions
- highly developed mechanism for cohension
- Display specialized structures that allow cells to communicate with each other
- complex patterns of tissue differentiation
When is diffusion effective?
Only over a short distance
When a cell is too big or thick
it limits the amount of oxygen that can enter the cell
How do sponges overcompensate for their size?
they use pores and canals in order to still gain access to seaweed
How do humans overcompensate for their size?
We circumvent diffusion by actively pumping
oxygen-rich blood through our bodies.
How do multicellular organisms overcompensate for their size?
- bulk flow for humans= blood vessels/ the cirulatory system
- bulk flow for animals= vassular tissues
Bulk flow
is how molecules move through
organisms at rates beyond those possible by diffusion across a
concentration gradient