X is mathematically an unknown.
Humans have 22 chromosome pairs and two sex chromosomes. Females have two X chromosomes; males have an X chromosome and a Y chromosome. ... In humans, animals, and plants, most chromosomes are arranged in pairs within the nucleus of a cell. Humans have 22 of these chromosome pairs, called autosomes.
Fossils are Remains Of Tracers Of Prehistoric Life
Answer:
A. Type of soil
Explanation:
A control experiment is the one that is used to checkmate the real experiment.
In this case, the fourth jar that contains the mixture of all the types of the soil is considered as the control experiment.
In a nutshell, it should be generally understood here that the type of soil serves as the control for the experiment.