Sponges, members of the porifera, might be the simplest multicellular animals on earth. they do not have any tissues, organs, or organ systems. in order for sponges to have evolved, what must have happened first? a) the organization of cells into groups b) symbiotic relationships among various cells c) the evolution of cells with nuclei and organelles d) the development of the cell wall as a protective mechanism

Amylase is an enzyme found in the human digestive system. why do you think it was important to keep the enzyme temperature about 37 degrees celsius (98.6 degrees f)? describe what might happened the temperature decreased by 10 degrees celsius.

Red flowered snapdragons are crossed with white flowered snapdragons, producing all pink snapdragons in the f1 generation. what would you expect if you crossed pink with pink? 3/4, 1/4, 1/2 red, 3/4,/1/2,/1/4 pink,1/2, 3/4, 1/4 white

In 1959, doctors began using the powerful antibiotic methicillin to treat infections of staphylococcus aureus, but within two years, methicillin-resistant strains of s. aureus (mrsa) appeared. how did the resistant strains of s. aureus emerge? in 1959, doctors began using the powerful antibiotic methicillin to treat infections of staphylococcus aureus, but within two years, methicillin-resistant strains of s. aureus (mrsa) appeared. how did the resistant strains of s. aureus emerge? staphylococcus aureus bacteria that were able to synthesize cell walls using a protein that was not affected by methicillin survived the methicillin treatments and reproduced at higher rates than did other individuals. over time, these resistant individuals became increasingly common. in response to treatment of staphylococcus aureus infections with methicillin, some bacteria began to synthesize cell walls using a protein that was not affected by methicillin. these bacteria survived the methicillin treatments and reproduced at higher rates than did other individuals. over time, these resistant individuals became increasingly common. in response to treatment of staphylococcus aureus infections with methicillin, bacterial populations gradually began to synthesize cell walls using a protein that was not affected by methicillin.