Ch. 1 - A Practical Investigation

The manipulation of variables

isolating a variable to investigate, and controlling the rest

Small invertebrates

slaters, snails, brine shrimps etc

Gather both qualitative & quantitative data (descriptive & numerical) to

→ Know how to care for it→ Determine the appropriate range for IV*→ Correctly control other variables not under investigation

Pros of using microorganisms for your study

Allows investigations to carried out __easily__ and __quickly__ in a *test tube*, *petri dish,* or under a *microscope*

Pros of using plants for your study

Easy to care for and grow; seeds = easy to access and cheap

Cons of using microorganisms

Very strict guidelines for what can be used

Cons for using plants

Can be time consuming to keep

Pros of using small invertebrates

Easy to find and look after; can give very rapid responses

Why should you research about your organism(s)’s habitat or ecological niche?

To ensure it is looked after correctly and the behaviour exhibited is due to the investigation, **not** physiological stress

independent variable

variable that is changed

dependent variable

variable that is measuresd

controlled variable

variable that remains constant throughout the whole study

The rule of thumb for a good method

simple and precise

Raw data should be put in the ________

appendix

These data representations show continuous data

Line graphs and histograms

Every graph must have

Title, labels, units

True or False: Your conclusion should restate the results and discuss the biological concepts relevant

False

Other studies should be used to ________

Support your findings

manipulation of variables

The ________- isolating a variable to investigate, and controlling the rest.