Cell wall because their has to be something protecting it.
        
             
        
        
        
Answer:
Well one of the types of symbiosis is parasitism. Here an example would be a tapeworm (parasite) would live in and feed off a living host (humans in our case)
Explanation:
 
        
             
        
        
        
The percentage of alleles for homozygous recessive would be 50%
        
             
        
        
        
The period of Convalescence is the time during which the person regains health and fully recovers.
Explanation:
-  Diseases that can spread from one person to other  are called infectious disease.
- Disease development is divided into Incubation period, Prodromal period, period of illness, Decline period, and period of Convalescence.
- During incubation period the pathogen enters the host body and starts multiplying itself. But the signs of diseases are unnoticeable.
- Then comes  the prodromal period, when the pathogen keeps multiplying itself and some signs of disease are observed but they are not obvious
- After the prodromal period comes the period of illness when the patient exhibits obvious signs of sickness.
- As the period of illness is over the symptoms of disease start to cease and the the number of pathogen decrease in body.This period is the period of decline.
- Finally comes the period of Convalescence when the person returns to his pre-disease state and is completely healthy. (except irreversible damage caused by the disease)