Answer:
A virus is alive; it can respond and/or adapt to changes in the environment.
Explanation:
Herpes simplex virus 1 is a sexually transmitted virus that causes genital herpes.The herpes virus is contagious can be spread through contact with saliva, such as sharing drinks. The virus is alive and responds to changes in environment by adapting to living in body fluids.
 
        
                    
             
        
        
        
I believe the answer is hormones. correct me if i'm wrong.
        
             
        
        
        
Answer:
crossing over
Explanation:
Crossing over is where homologs can exchange DNA which leads to genetic variation
 
        
             
        
        
        
Washing fruits because by washing you will decrease the bacteria’s
        
             
        
        
        
Answer:
21 chromosomes
Explanation:
Meiosis is a type of cell division that produces 4 haploid daughter cells (i.e., gametes) from a single diploid cell. This parental cell undergo one (1) cycle of DNA replication and two (2) cell divisions, thereby, in the case of the Norway rats that have 42 chromosomes, the final number will be 21 (21 x 2= 42)