Proteins are made up of a chain of 20 amino acids
        
             
        
        
        
The answer is an average couple is fertile for only 6-7 days.  If a couple cannot produce healthy sperm and egg there are the various treatment to help infertile couples to become pregnant and can have their own child. Infertility happens if there is the failure to conceive consecutive 12 months despite the attempts.
 
        
             
        
        
        
The answer is B. The cardiac, respiratory, and vasomotor
control centers are in the medulla. This means that the medulla controls heart
rate, blood pressure, breathing, and the size of the body's blood vessels. They
have chemoreceptors, pH sensing structures that detect levels of carbon dioxide in the blood and adjust the breathing rate accordingly. 
 
        
             
        
        
        
Answer: Comparing the DNA sequence of the organisms can also tell you how closely related species they are. It can give you even more information since the original DNA is how the amino acid sequence of cytochromes is coded for.
Looking at embryonic development also helps you determine the phylogeny of organisms because a way an embryo develops can be very similar to the way another species develops but then both are full-grown they look very different and its tuff to explain how close they might be related
 
        
             
        
        
        
Answer:
Principles by Mendel
Explanation:
The heritage principles of Gregor Mendel are at the core of modern genetic engineering. Mendel has created three heritage principles by conducting experiments with pea plant breeding, which described the passing on of genetic characteristics before anyone thought that genes did exist.Mendel referred to this components as "elementen" and suggested that, throughout sexual reproduction, each parent contributes a form of elementary elementen to the resultant offspring. This blend of parental elementen then defined what type of characteristic was noticeable in the descendants.
Genetic concepts are laws or guidelines regulating the biological heredity process, the transition of parents' to children's attributes by information that is biochemically transmitted by DNA, to gene units.