Pick up after pets, plant trees, reduce plastic usage
        
                    
             
        
        
        
Plants regulate their water levels in two main ways: Stoma and Vacuoles.
Stoma are bean shaped cells on the leaf that allow water and gas to exit. They open and close to regulate water.
Vacuoles are organelles that store water and fluids, which help regulate them.
        
             
        
        
        
The homo erectus is the most common ancestor with modern humans
        
             
        
        
        
Answer:
12 : 3 : 1
Explanation:
According to Mendel's principles, a dihybrid cross between two heterozygous summer squash parents (WwGg X WwGg) should yield offsprings, 12 with white, 3 with yellow and  1 with green color phenotype. The classic Mendelian phenotypic ratio for dihybrid cross is 9:3:3:1. In this case, genotypes W- G- and W- gg produce white color phenotype. This is because we have 12: 3: 1 phenotypic ratio in which the alleles of two different genes assort independently into gametes.
<em>Dihybrid cross for heterozygous summer squash:</em>
                      WG         Wg            wG            wg           
      WG       WWGG   WWGg     WwGG     WwGg
      Wg        WWGg   WWgg     WwGg      Wwgg
      wG        WwGG    WwGg     wwGG      wwGg
       wg        WwGg    Wwgg     wwGg        wwgg
    Genotypes:
    W-G-  and W- gg  = white = 12
     ww G- = yellow = 3
      ww gg = green = 1