The layers above would be not as old and the layers below would be the older layers.
        
                    
             
        
        
        
Answer:
body's water needs, conserving water if the body is dehydrated or making urine more dilute to expel excess water when necessary. ADH is a hormone that helps the body to retain water by increasing water reabsorption by the kidneys.
Explanation:
i hope it helps
 
        
             
        
        
        
Marie is experiencing the: Sympathomimetic effects (fight-or-flight state).
The sympathetic nervous system is a component of the autonomic nervous system, managing the activity of visceral organs and the automatic functions of the body, such as breathing or beating of the heart. The sympathetic nervous system is involved in many unconscious physiological activities through two neuromodulators of the catecholamine family: adrenaline, but especially norepinephrine (fight-or-flight hormones).
* It accelerates the metabolism and is activated for example in case of danger or fear, to prepare the individual to escape.
* It affects the cardiovascular system: it increases the heart rate and induces peripheral vasoconstriction, causing an increase in blood pressure.
* At the digestive level, it slows the muscular contractions of the intestines but promotes the release of glucose by the liver.
* It also has a bronchodilator effect, that is to say, it causes the increase of the diameter of the bronchi.
        
             
        
        
        
Answer:
Natural selection causes change in allele frequencies within a population.          
So option A is correct one. 
Explanation:
Natural selection generally  work  on an organism’s phenotype, or observable features. Phenotype is often largely a product of genotype (the alleles, or gene versions, the organism carries). When a phenotype produced by certain alleles helps organisms survive and reproduce better than their peers, natural selection can increase the frequency of the helpful alleles from one generation to the next – that is, it can cause microevolution.