We use blank as the matrix through which DNA will travel. In order to physically see the samples that we put in the gel, we first have to add blank to each sample. When we have the samples loaded, we want to make sure we also add what's called a blank which acts as the standard curve in a tube; it's made up of DNA fragments of known sizes. Before running the gel, it's important to make sure that there is blank covering the gel in the gel rig. This will make sure that the electrical current runs through the gel and the gel stays cool

This question is asking to fill in the blank spaces with the correct terms. The correct terms to the four blank spaces are:

1) GEL

2) DYE

3) DNA MARKER

4) LID

Explanation:

This question is describing the Gel electrophoresis technique which is used to separate DNA fragments using electric current. The DNA fragments of different sizes migrate through a GEL which serves as the matrix made from Agarose.

In order to physically see the samples that we put in the gel, we first have to add DYE to each sample of DNA. After loading the samples to be separated, a substance made up of DNA fragments of known sizes referred to as DNA MARKER, which acts as the standard curve in a tube is used.

Before running the gel, it's important to make sure that there is LID covering the gel in the gel rig. This will make sure that the electrical current runs through the gel and the gel stays cool.

the answer is b: 1.4 km/hr