Which elements are constants or variables?

Have a look at the information to be gathered for a feed trial involving two different types of feeds. These trials are to be run concurrently, that is, at the same time and under the same conditions (except different feeds are given), to determine which feed is more efficient.

Have a look at each element and decide whether each is a constant, an independant vartiable or a dependant variable. Then check your answers below.

Identified trial elements:

Stock number.

Species.

Ponds.

Time period.

Interval (e.g. daily).

Type of feed given to stock.

Stock weight.

Conditions e.g. water quality and quality of feed.

Formulas for calculating:

• Mortality rates.
• Daily survival rate.
• Food conversion ratio (FCR).
• Average FCRs.

Recording information.

 

 

Answers

Identified trial elements:

Stock number - Constant.

Species - Constant.

Ponds - Constant.

Time period - Constant.

Interval (e.g. daily) - Constant.

Type of feed given to stock - Independant variable.

Stock weight - Dependant variable.

Conditions e.g. water quality and quality of feed - Constant.

Formulas for calculating:

• Mortality rates - Constant.
• Daily survival rate - Constant.
• Food conversion ratio (FCR) - Constant.
• Average FCRs - Constant.

Recording information - Constant.