Answer:
1/4
Explanation:
Given that the F2 cross produces offspring according to the expected 9:3:3:1 ratio. 
YyRr X YyRr:
Let us break the dihybrid cross into individual monohybrid crosses. 
Yy X Yy :
     Y     y
Y  YY  Yy
y   Yy   yy
2/4 or 1/2 of the offspring are heterozygous for the trait.
Similarly, in Rr X Rr cross, 1/2 of the offspring are heterozygous for the trait.
Together, 1/2 * 1/2 = 1/4 of F2 plants are expected to be heterozygous for both traits.
 
        
             
        
        
        
Reduce carbon dioxide emissions, pollution, and deforestation
reuse materials rather than throwing them away and needing to create more
recycle materials like metals, paper, and plastics
replace non-biodegradable materials with biodegradable
        
             
        
        
        
Answer:
c) The species underwent punctuated equilibrium 
e) The species’ environment underwent a dramatic change for which it was poorly suited
Explanation:
 
        
             
        
        
        
The answer is c because we just learned about it today. Viruses destroy cells