Osmosis, Cell Responses, Graphing, and Statistical Analysis Vocabulary

Vocabulary flashcards covering osmosis principles, cell behavior in varying water potentials, laboratory protocol limitations and improvements, graphing standards, and statistical evaluations.

Osmosis

The net movement of water from a higher (less negative) to lower (more negative) water potential across a partially permeable membrane.

Turgid Plant Cell

A plant cell state resulting from being placed in a solution of higher water potential, causing water to move into the cell down the water potential gradient by osmosis.

Plant Cell Wall (Osmosis)

A cell structure that provides strength and withstands internal pressure to prevent the cell membrane from over expanding, limiting water uptake and preventing the plant cell from bursting.

Plant Cell in Lower Water Potential Solution

A state where water moves out of the plant cell by osmosis, down the water potential gradient from a higher to a lower water potential.

Cell Lysis

The bursting of an animal cell when placed into a solution of higher water potential due to water moving into the cell by osmosis down the water potential gradient.

Crenation

The shriveling of an animal cell when placed into a solution of lower water potential due to water moving out of the cell by osmosis down the water potential gradient.

Graph Plotting Rules

Guidelines specifying correct X and Y axes with units, linear scale taking up $>50\%$ of size, points plotted to $1\,\text{mm}$ of data, a curve of best fit, and error bars above and below each data point to within $1\,\text{mm}$.

Cell Water Potential (Graph Determination)

The water potential determined from a graph by finding the point of no change in mass where the line crosses the X axis.

Student's t-test

A statistical test used to decide whether or not the difference between the means of two sets of data is significant.

Rejection of Null Hypothesis (T-test)

The statistical decision made when the T value is greater than the critical value, concluding that there is a significant difference between the means due to biological reasons.

Repeatability Improvement

Repeating a practical procedure and taking a mean, which allows the effect of anomalous results to be reduced.

Intermediate Concentrations

An experimental technique of testing additional concentration values between existing data points to make the practical results more accurate.

Potato Skin Limitation

An experimental issue where skin left on potato tissue reduces osmosis into the cells; corrected by removing the potato skin.

Standardized Solution Volume Improvement

Using a known volume of salt solution for each test tube that fully submerges the potato chip and provides sufficient surface area for osmosis.

Potato Chip Blotting Improvement

Drying potato chips until no excess water remains on the chip, preventing surface water variation from affecting mass measurement.

Error Bars

Plot lines on a graph showing the spread of data away from the mean, where smaller error bars indicate greater repeatability of the experiment.

Calculation of the Mean

A mathematical procedure that minimizes the effect of anomalies or data variation and enables the calculation of standard deviation and statistical tests like the t-test.

Mean Percentage Change in Mass

A relative measurement that allows comparison and shows proportional change across tissue cylinders that have different starting masses or weights.