When the first antibiotics became available in the late 1940s and early 1950s, these antibiotics were effective against all bact
erial infections. Today however, there are a multitude of antibiotic resistant bacterial infections. What conclusion can be drawn? A) Antibiotics of today are not as strong as those in the past. B) Antibiotics cause DNA mutations in bacteria, and over time, this has led to resistance. C) Over time, bacteria have turned into viruses, and antibiotics have no affect over viruses. D) Bacteria have become resistant to antibiotics over time due to evolution by means of natural selection.
After many generations, only those with genes suitable to live in harsh environments can live. These genes are passed onto their offspring and then we see a rise in antibiotic resistant strains of bacteria such as Methicillin Resistant Staphylococcus Aureus (MRSA).
When a leaf is placed in a solution whose salt concentration is higher than the salt concentration of the leaves, the water with in the leaves shall move out of the leaves due to the osmotic pressure gradient. This will cause the plant cell devoid of water thereby leading them to shrink and wilt.
