Which statement best describes an effect of natural selection on a species?

B is correct because in natural selection, if a population cannot adapt over time it will be “naturally selected” and die off, or be near extinction due to non-adaptive ness. Hope this helped!

Which substances may form in the human body due to invaders entering the blood?

Antibodies (immunoglobulins) are proteins that are produced by white blood cells called B cells and that tightly bind to the antigen of an invader, tagging the invader for attack or directly neutralizing it. The body produces thousands of different antibodies. Each antibody is specific to a given antigen.

When the antibiotic penicillin was first introduced it was immediately effective in combating?

Terms in this set (36) When the antibiotic penicillin was first introduced, it was immediately effective in combating staphylococcal bacterial infections. After a number of years, there were outbreaks of staphylococcal infections that did not respond to treatment with penicillin.

What factors cause antibiotic resistance?

In summary, the 6 main causes of antibiotic resistance have been linked to:

• Over-prescription of antibiotics.
• Patients not finishing the entire antibiotic course.
• Overuse of antibiotics in livestock and fish farming.
• Poor infection control in health care settings.
• Poor hygiene and sanitation.

How do you develop antibiotic resistance?

Bacteria develop resistance mechanisms by using instructions provided by their DNA. Often, resistance genes are found within plasmids, small pieces of DNA that carry genetic instructions from one germ to another. This means that some bacteria can share their DNA and make other germs become resistant….

What happens if you are resistant to antibiotics?

When bacteria become resistant, the original antibiotic can no longer kill them. These germs can grow and spread. They can cause infections that are hard to treat. Sometimes they can even spread the resistance to other bacteria that they meet.