Genetic Change in Viruses. Viruses are continuously changing as a result of genetic selection. They undergo subtle genetic changes through mutation and major genetic changes through recombination. Mutation occurs when an error is incorporated in the viral genome
        
             
        
        
        
<span>If jogging you should start off with a brisk walk and transition after about 1 minute to a slow jog. Then pick up your pace as your legs become warm with increased blood flow. If biking you should do a few static calf and thigh stretches but don't extend too far as muscles are cold. Then start off your cycling at a very slow comfortable pace. After about a minute you can start to slowly increase your pace until you reach your goal.</span>
        
             
        
        
        
<span>Ions are another name for charged atoms. Some elements are electropositive, and some are electronegative. Electropositive elements such as metals like to give up electrons, thus taking on a positive charge. Electronegative elements such as chlorine attract electrons, so they become negative. When electropositive and electronegative atoms meet and exchange ions, they take on opposite charges. Because positive and negative charges attract, these charged atoms become attracted to one another. This attraction forms an ionic bond that keeps the ions together.</span>
        
                    
             
        
        
        
Answer:
The correct answer is A    DNA  is replicated before mitosis begins
Explanation:
DNA replication is one of the most significant event of a cell cycle. .DNA replication occur in the S phase or synthesis phase of the cell cycle.
        DNA is replicated once per cycle to maintain to normal chromosome number in daughter cells.
      DNA is replicated to form two new DNA molecules which are then equally distributed in each daughter cell during the mitosis phase.
 
        
             
        
        
        
Answer:
In biology, the smallest unit that can live on its own and that makes up all living organisms and the tissues of the body. A cell has three main parts: the cell membrane, the nucleus, and the cytoplasm. ... Parts of a cell. A cell is surrounded by a membrane, which has receptors on the surface.
The heart consists of four chambers in which blood flows. Blood enters the right atrium and passes through the right ventricle. The right ventricle pumps the blood to the lungs where it becomes oxygenated.
Explanation: