Osmosis Flashcards – AQA GCSE Combined Science: Trilogy (8464) — Biology — Higher

What is osmosis?

The diffusion of water through a partially permeable membrane.

In which direction is the net movement of water by osmosis between solutions of different concentrations?

From the more dilute solution to the more concentrated solution.

Why can water move into or out of a cell by osmosis?

The cell membrane is partially permeable.

How do you calculate the percentage change in plant tissue mass?

$\frac{\text{final mass} - \text{initial mass}}{\text{initial mass}} \times 100\%$

What do positive and negative percentage changes in plant tissue mass indicate?

A positive result indicates a percentage gain; a negative result indicates a percentage loss.

Why do percentage changes allow plant tissues with different starting masses to be compared?

Each change is expressed relative to the tissue’s initial mass.

What does an experimental graph represent?

The relationship between measured variables.

Which variables go on the horizontal and vertical axes of an experimental graph?

The independent variable goes on the horizontal axis; the dependent variable goes on the vertical axis.

What should each axis of an experimental graph be labelled with?

Its quantity and unit.

How should scales be chosen for an experimental graph?

They should use the graph space clearly and allow values to be plotted accurately.

How should experimental data be represented on a graph?

Choose an appropriate graph type, plot the data, and draw a suitable line, curve or bars.

What does interpreting an experimental graph involve?

Reading values and describing the patterns, relationships and changes shown.

What does the gradient of a line graph indicate?

How much the vertical quantity changes for a change in the horizontal quantity. Its meaning depends on the variables and units on the axes.