Science ch5 summaries( cytology)

The cell theory states that…

Cells are the structural and functional units of all living things and that cells come only from other pre-existing cells

Unicellular

Single celled, (colonial) multiple cells that can each live independently

Most cells in multicellular organisms are specialized for certain tasks and are organized into…

Tissues, organs, and organ systems

Every cell contains a multitude of specialized organelles that

Carry out the different functions, needed to live, grow and reproduce

Eukaryotic cells have

Membrane bound, organelles, and a membrane bound nucleus that prokaryotic cells do not have

All cells must work to maintain homeostasis

A condition of dynamic equilibrium with their environment

Cells use feedback mechanisms to maintain homeostasis. Positive feedback occurs when.

A substance involved in a cellular process causes the process to speed up

Cells use feedback mechanisms to maintain homeostasis. Negative feedback occurs when…

A substance produced by a cellular process, causes the process to slow down or stop

A cell semipermeable membrane allows water to easily diffuse in or out. In an isotonic solution, the rates of flow and outflow are….

Balanced

A cell semipermeable membrane allows water to easily diffuse in or out. In a hypertonic solution a…

Net outflow occur occurs, resulting in dehydration also in a hypotonic solution, Annette and flow occurs, causing swelling

Cells have different means for transporting substances through their cell membrane. The method required for a particular substance depends depends on….

The substance particle size, particle shape, particle, polarity, and the composition of the cell membrane

Passive transport, either diffusion or facilitated diffusion does not require…

The cell to expand energy and always occurs along the concentration gradient between a cells, interior and exterior environments

Active transport methods require..

Energy and can move substances against a concentration gradient