Adaptation is the correct answer
Chromosomes are thread-like structures in which DNA is tightly packaged within the nucleus.
Classifying things by observation can best be done by using a : Taxon
Taxon divided organisms into different groups based on their unique similarities, which is the best way to classify things if you're doing it by observation.
The plant population would grow out of control
I think the correct answer from the choices listed above is option A. In plants, the purpose of auxins is to produce phytochrome. The main function of auxin is to help plants grow. Auxin stimulates plant cells to elongate, and the apical meristem of a plant. Hope this answers the question.