Answer:
1. Circulatory System
2. Respiratory System
3. Endocrine System
4. Nervous System
5. Urinary/ Excretory System
Explanation:
1. Circulatory System- The heart pumps blood and blood vessels such as arteries and veins, transports the blood to every part of our body providing organs and muscles with nourishment.
2. Respiratory System- This system maintains our breathing. It supplies the body with oxygen for cellular respiration.
3. Endocrine System- The glands of the endocrine system secrete chemicals called hormones that regulate most of the processes in our bodies like growth, reproduction, metabolism, etc...
4. Nervous System- The entire nervous system controls all of the other systems of the body and it also transmits information to the brain, such as pain and external sensations.
5. Urinary/Excretory System- This system is responsible for eliminating waste products of metabolism and other materials from the body that are of no use. 
 
        
                    
             
        
        
        
Answer: Exons
Explanation:
In eukaryotic cell the primary transcript are very long the contains coding region (exons) and non coding region (introns) 
The parts of the gene sequence that are expressed (coding region) in the protein are called exons, because they are expressed, while the parts of the gene sequence that are not expressed in the protein are called introns, because they come in between the exons.
 
Intron is a portion of a gene that does not code for amino acids. These Intron sequence are cleaved out and exons are spliced (I. E combine together) to form the mature mRNA molecule.
Exons are the mRNA parts that are kept and used to make protein. 
 
        
             
        
        
        
Natural selection involve natural causes while artificial selection is by human breeding or human intervention.
The process of domestication is called artificial selection. Like natural selection, artificial selection acts by allowing differential reproductive success to individuals with different  genetically determined traits in order to increase the frequency of desirable traits in the population. Natural selection and selective breeding can both cause changes in animals and plants. The difference between the two is that natural selection happens naturally, but selective breeding only occurs when humans intervene. 
        
             
        
        
        
Answer:
The relative frequency of an allele is all the genes that are present in a the gene pool of a population
Explanation: