Review for District Final

The following is what we talked about in class for review for the District Final:

Homeostasis – The body keeping a balance in the body. Includes water percentages, salts, body temperature, pH, Oxygen amounts, etc.  Think of ways we keep our body in balance– i.e. diffusion, osmosis, shivering, sweating, breathing rates, etc.

Diffusion– The movement of PARTICLES, not water to balance concentrations.  Includes salts, minerals, metals, anything except water.

Osmosis- The balancing of particle concentrations when the particles are unable to cross a membrane.  The water then moves to dilute the side of the membrane with the higher concentration.

Hypotonic– When the particle concentration outside a cell is lower than inside a cell– therefore the water moves inside the cell, causing it to get bigger.

Hypertonic- When a particle concentration is greater on the outside of the cell, than the inside of the cell- therefore the water moves from inside to outside, shrinking the cell.

Remember– the cell wall of a plant does not change with solution concentration.  It stays the same–Only the membrane on the inside will shrink or grow with the water movement. This is the exception for plants only- since animals don;t have cell walls.

Scientific method–
Problem–  If…… then…… ?
Hypothesis- If…..then…… statement.
Materials
Data–   Qualitative–Data that is an opinion — Senses
Qualitative– Data that is numbers based. measurements.
(experiment MUST have quantitative)
Conclusion

Graphs– Be sure to label units, Title, and the independent variable (usually time) goes on the X axis.  Dependent is on the Y axis.

Evolution– RANDOM mutations, (can’t choose-create-need, want or learn a mutation).  Must be selected for by Natural Selection, takes time and must reproduce to pass the ‘good’ mutation on to next generation.

Lamarckism– Can pass on acquired traits-  You lose your pinky– your children born without a pinky.  Silly!  He was wrong.

Cell membrane– Large particles unable to go into cell.  Hydrophilic phosphate heads of membrane like water- and allow it to pass easily (passive transport).  Protein channels are used to get big molecules through the membrane. Needs energy to get through (active transport) – or a ‘key’ like insulin to let sugars into cells.