State Standard

SB5E. Recognize the role of evolution to biological resistance (pesticide and

antibiotic resistance)

Biological Resistance (15.2)

Antibiotic Resistance

Bacteria reproduce quickly and their population grows rapidly.

Mutations can lead to traits that allow certain individuals to be immune to antibiotics.

These survivors then reproduce quickly (cloning themselves) and establish a population of antibiotic resistant bacteria.

15.3 Natural Selection-Speciation-Resistance

Chapter 15

Antibiotic Resistance Cont’d

15.3 Natural Selection-Speciation-Resistance

Ch. 15

Antibiotic Resistance Cont’d

The overuse of antibiotics has caused antiobiotic-resistant populations of bacteria to become a dangerous problem.

Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterium that causes infections in different parts of the body. It's tougher to treat than most strains of staphylococcus aureus -- or staph -- because it's resistant to some commonly used antibiotics

15.3 Natural Selection-Speciation-Resistance

Ch. 15

Antibiotic Resistance Cont’d

15.3 Natural Selection-Speciation-Resistance

Ch. 15

Typical appearance of MRSA infection

Pesticide Resistance Pesticides may kill most members of an insect

population, but variation allows some individuals to be immune to pesticides.

Those who are immune are able to survive and reproduce, passing their immunity trait to the next generation.

Soon, a whole population of pesticide-resistant insects is thriving.

15.3 Natural Selection-Speciation-Resistance

Ch. 15

Pesticide Resistance

15.3 Natural Selection-Speciation-Resistance

Ch. 15

• Overuse of pesticides has allowed more and more resistant populations to develop.