The extermination of the dinosaurs, the start of a rise to dominance of mammals and a meteorite effect in mexico marks the boundary among the mesozoic and the cenozoic or as named as the k-p boundary. In addition, the cretaceous paleogene (K–Pg) boundary which is previously recognized as the cretaceous tertiary (K–T) boundary is a geological signature typically a thin band of rock.
Answer:
The trachea branches into two tubes called bronchi (one to each lung). The bronchi split into smaller and smaller tubes called bronchioles, which then end in microscopic alveoli (air sacs). ... The layer of moisture in the alveoli allows gases to dissolve so that they can diffuse quickly.
A cell maintains homeostasis through division and repair. The cell cycle has three, stages that are used to help a cell maintain homeostasis. Photosynthesis in a plant cell makes glucose and oxygen for the cell. Then the cell uses that glucose and oxygen to do cellular respiration for the cell to live and function.
Answer:
Penicillin:
Staphylococcus epidermidis is more sensitive to Penicillin as compared to E. coli
Novobiocin:
Staphylococcus epidermidis is more sensitive to Novobiocin as compared to E. coli.
Gentamicin:
E. coli isolates showed high rates of resistance to gentamicin as compared to Staphylococcus epidermidis
Explanation:
Kirby-Bauer diffusion test:
This test is also known as disk diffusion antibiotic sensitivity testing. This test uses antibiotic containing disks to test its inhibition against particular bacteria.
Staphylococcus epidermidis:
Gram-positive bacterium, which is part of the normal human flora and found mostly in skin flora but less commonly in mucosal flora.
E. coli
Gram-negative bacteria because its cell wall have an additional layer. During the staining process, it stains negative as compared to gram positive bacteria.
Penicillin:
This antibiotic kills bacteria by inhibiting the final step in cell wall biosynthesis, hence penicillin is most effective against gram-positive bacteria. Hence Staphylococcus epidermidis is more sensitive to Penicillin as compared to E. coli
Novobiocin:
Antibiotics which inhibits bacterial DNA synthesis. Its targets are the bacterial DNA gyrase and associated enzyme DNA topoisomerase. Due to extra membrane present outside gram negative bacteria this antibiotic is less effective against E. coli. Hence Staphylococcus epidermidis is more sensitive to Novobiocin as compared to E. coli.
Gentamicin:
Gentamicin is the broad spectrum antibiotic Its mode of action involves bacterial protein synthesis inhibition by binding to 30S ribosomes. E. coli isolates showed high rates of resistance to gentamicin as compared to Staphylococcus epidermidis
