The sentence which is true or a fact about the virus is the sentence in letter B. Viruses can reproduce only within other cells. <span>Viruses are intracellular obligate parasites they can not replicate or express the genes with out living host. </span>
<span>viruses are acellular so they have to rely on host cellular machinery for reproduction. </span>
<span>viruses doesnot contain any enzymes for reproduction</span>
        
             
        
        
        
Explanation:
In general, tumors occur when cells divide and grow excessively in the body. Normally, the body controls cell growth and division. New cells are created to replace older ones or to perform new functions.
 
        
                    
             
        
        
        
Answer:
The edges or boundaries between the ecosystems and within it are the illustrating characteristics of landscapes. In a landscape, the biodiversity is affected by the composition of the landscape itself. When an area possesses boundaries or edges, which minimize the area of the habitat, it also starts to minimize the number of species, which can associate with the communities.  
The multiplication of edge species can exhibit both negative and positive influences on the biodiversity of a community. On the other hand, corridors refer to the region associated with the populations of wildlife distinguished by human activities like road construction. The prime objective of designing habitat corridors is to enhance biodiversity. The corridors that have been protracted to other habitat patches can reinstate a certain degree of space and at the same time reestablish certain chances for genetic diversity.  
 
        
             
        
        
        
Answer:
d) The enzyme changes shape and can no longer speed up the reaction
Explanation:
Enzymes aare protein in nature therefore sensitive to changes in temperature. Most enzymes have an optimum temperature ranging from 35-40°c. As the temperature increases, optimum temperature is reached where the rate of reaction is maximum. Temperatures above 40-63°c denatures the enzymes making them non effective thus the reaction decreases sharply.