Answer:
a. Marigold with no fertilizer
Explanation:
An experiment contains variables including independent and dependent variables. The independent variable is the variable that is changed by the experimenter, which is the TYPE OF FERTILIZER in this case, while the dependent variable is the measured variable, which is the GROWTH OF MARIGOLDS in this experiment.
However, a control group is a group that does not receive any experimental treatment. In other words, the independent variable is unchanged in the control group. The control group is regarded as the "normal" used to compare with the experimental group (group that receives treatment). In this experiment, the group of marigolds that DOES NOT RECEIVE FERTILIZER is the control group.
Based on this diagram, the organism is classified based on some similarities. In the upper-division, the similarities should be more general in the lower division, the similarities will be more specific. It was mostly based on an organ, for example: vertebrate.
An organism with the same phylum could be put in a different order.
But the organism with the same order should have the same phylum and class too since the order is located below the phylum. Those similarities are tightly correlated with the evolutionary relationship.
It is referring to natural selection
Vascular tissue<span> is a complex conducting </span>tissue<span>, formed of more than one cell type, found in </span>vascular plants<span>. The primary components of </span>vascular tissue<span> are the xylem and phloem.</span>