Answer:
gravitational force
Explanation:
Gravitational force is the force responsible for firmness while standing.
 
        
             
        
        
        
Answer & explanation:
Amylase is part of enzymes, a group of large peptide molecules (formed by amino acids) whose role is to catalyze reactions in order to facilitate the synthesis of other biological molecules.
Amylase is found mainly in saliva (in the form of salivary amylase, or ptialin), acting in the breakdown of starch and glycogen in foods, reducing them to smaller particles, facilitating their digestion and absorption. 
The action of enzymes depends on certain specific conditions, called optimal conditions. In the case of <u>amylase</u>, it depends on an optimum pH of 7 (neutral) and an optimum temperature of approximately 37 ° C. 
This enzyme can still act between 35 ° C and 40 ° C, but below 35 ° C it is inactivated, preventing its functions from being performed, and above 40 ° C it suffers denaturation, causing changes in its structures.
Thus, it is concluded that the <u>temperature</u> (under optimal conditions) is important for enzymes because it keeps their actions and structures in proper operation.
 
        
             
        
        
        
Your answers would be:
1. ---- B. A cell cannot be subdivided into smaller units that maintain the living state.
2. ---- The organism is a eukaryote because it has a nucleus. 
3. ---- D. Water would flow into them because they are hypertonic to external environment. 
If you want to know why:
1. The cell is the basic unit of life or in other words, its the smallest unit that makes up a living thing. It does not subdivided further if you are talking about sustaining life. Yes, it is made up of smaller units of organelles, but these organelles work together as a single unit (as a cell), to do life sustaining processes.
2. The organism is a eukaryote because of the presence of a nucleus. This is one of the main features of a eukaryote that differentiates it from a prokaryote. Prokaryotes to not have a true nucleus. 
3. Water would flow into them, causing the cell to swell and eventually burst if the concentration of solutes would not even out before then. The process of osmosis is what brings the water into the cell. The cell would have a higher solute concentration than freshwater. Through osmosis, the water would then go to the area of higher concentration, which would be the cell. 
 
        
                    
             
        
        
        
The answer is Habitat. The brackish water environment is formed due to the mixing of fresh water from the river with the salty waters of the ocean. This habitat is significant for fishes that come to spawn and feed. Crabs, mosquitoes and birds can also be found in this environment.