Answer:
animals that eat only plants.
 
        
                    
             
        
        
        
Oxygen is an abiotic factor that is beneficial by-product of primary production.
<u>Explanation:</u>
The non living parts of an ecosystem that mainly affects the living organisms in it are called as an abiotic factor. These can include soil, temperature, water, oxygen and sunlight. The major energy source in earth is Oxygen which is abiotic factor. 
It is very essential for the photosynthesis process to take place. Here, the plants converts water and carbon dioxide into oxygen and sugar. This becomes food for plants. Then these plants are eaten by animals. Thus oxygen is an important and beneficial by-product of photosynthesis. Oxygen is also very important for the survival of human beings. 
 
        
                    
             
        
        
        
Recessive traits are visible in the organisms phenotype as long as TWO recessive traits are present.
        
             
        
        
        
Answer:
Usually the Y chromosome. It is recessive because if one Y chromosone is mutated with red-green colorblindness and the X is not, the child will have colorblindness. But, if one X chromosome has the mutation and the other X does not, they will cancel out, meaning the child will not have colorblindness.
 
        
             
        
        
        
ANSWER: MITRAL VALVE STENOSIS
EXPLANATION:
The child have the risk of having MITRAL VALVE STENOSIS. It is also referred to as mitral stenosis.
Mitral valve stenosis occurs as results of the mitral valve opening narrowing. Which effect to less blood flowing through it.
The mitral valve is located between two chambers (the atrium and the ventricle) on the left side of your heart. 
However, Mitral valve stenosis can lead to different health issues, including blood clots, difficulty breathing, fatigue, and heart failure.
Mitral valve stenosis is specifically caused by rheumatic fever (a childhood disease). This rheumatic fever occurs has a result of the body's immune response to an infection associated with the streptococcal bacteria. 
Acute rheumatic fever affects the joints and the heart greatly. It causes joints inflammation temporarily and in severe case causes chronic disability.
Nevertheless, this cardiac complication have treatment and it is based on whether the affected individuals shows symptoms. Medications like blood thinners or anticoagulants (to reduce the risk of blood clots), diuretics, antiarrhythmics (to cure abnormal heart rhythms), beta-blockers (to slow your heart) etc, are being administered based on the level of the complication.