Final answer:
The spectrum of coverage of 3rd generation cephalosporins is broader than that of generations 1 and 2, extending to gram-positive and many gram-negative bacteria.
Step-by-step explanation:
The spectrum of coverage of 3rd generation cephalosporins differs from generations 1 and 2 in terms of their ability to treat a broader range of bacteria.
First-generation cephalosporins are primarily effective against gram-positive bacteria, while second-generation cephalosporins have a slightly broader spectrum that includes some gram-negative bacteria. Third-generation cephalosporins have an even broader spectrum and are effective against both gram-positive and many gram-negative bacteria, including some that are resistant to earlier generations of cephalosporins.