C.specialized cells
such as choanocyes which grab food when filter feeding
        
                    
             
        
        
        
Answer:
Explanation:
1- the purpose of blood flow-circulatory system- is to convey  Oxygenated blood, oxygen bonded with haemoglobin in the RBC with Nutrients - and distributed these through the arteries  and capillaries  away from the heart,  to reach the cells and tissues, and transported the wastes of theses cells and tissues , with C02 through the veins back to the heart and the kidney.
2. During diastole,deoxygented blood from the inferior and superior vena cavae entering the R.atrium, passes through the tricuspid valve into the Right Ventricle. Simultaneously, oxygenated blood returning through the pulmonary veins enters the left Atrium,emptied  through the bicuspid valve into the Left.Ventricle.
During systole, the two ventricles contracts. The Right ventricle contracts, the pressure of the blood forces  the tricuspid valve to close,and therefore de -oxygenated blood pushes the pulmonary  valves to open and blood passes through the pulmonary artery to reach the lungs where exchanges of oxygen with carbon dioxide occurs.The blood is now oxygenated and returns to the left atrium via pulmonary veins. 
Simultaneously, the left ventricle contracts,the oxygenated blood it contains forced the bicuspid valve to close so that blood is  forced through the aortic valve  to empty into the aorta into  the systemic circulation,branches of the carotid artery supplies the heart from the aorta.
The Whole cycle continues.
 
        
             
        
        
        
"When there are multiple mutations in a gene" is the one among the following choices given in the question that <span>is a mutated gene most likely to be passed along to offspring over several generations. The correct option among all the options that are given in the question is the second option or option "B".</span>
        
             
        
        
        
Answer:
A. Chemical modification may allow for extended drug capacities such as expanded spectrum of activity and increased stability.
Explanation:
Any modification in antibiotic structure and chemical will affects its ability in a way to increase it capability of target microbes and act efficiently. These modification can increase half life and stability of the drug.