Answer:
The fourth plant that receives pure water is the control group.
Explanation:
The election of a control group is essential in an experiment. Its principal purpose is to allow the discrimination of the results obtained by the treatment in the study, in this case, <em>the different concentrations of salty water that each plant receives</em>. The control group provides a reference point. It must be selected from the same population of the treatment groups. Both groups must be similar in every variable that might influence the results, <u>except for the study treatment.</u>
Answer:
Cofilin binds to older actin filaments
Explanation:
Microfilaments (also called actin filaments) are a class of protein filament common to all eukaryotic cells, which consist of two strands of subunits of the protein actin. Microfilaments form part of the cell's cytoskeleton and interact with the protein myosin in order to allow the movement of the cell. Within the cell, actin may show two different forms: monomeric G-actin and polymeric F-actin filaments. Microfilaments provide shape to the cell because these filaments can depolymerize (disassemble) and polymerize (assembly) quickly, thereby allowing the cell to change its shape. During the polymerization process, the ATP that is bound to G-actin is hydrolyzed to ADP, which is bound to F-actin. ATP-actin subunits are present at the barbed ends of the filaments, and cleavage of the ATP molecules produces highly stable filaments bound to ADP. In consequence, it is expected that cofilin binds preferentially to highly stable (older) filaments ADP-actin filaments instead of ATP-actin filaments.
