Answer:
In the entire solar system, the environment of planet earth is unique due to the presence of the atmosphere.
It is responsible for providing carbon dioxide and oxygen which are essential for the presence of life on earth.
Secondly, it helps in keeping the earth warm through the greenhouse effect.
It prevents the entry of harmful radiations of the sun into the atmosphere.
D. would be the answer because they are all within the eukaryote kingdom
Answer:
The order of events would be:
4.Threshold stimulus, Na+ channels open. This is the first event
5.Na+ influx, Depolarization. Second event
2.Na+ channels close, K+ channels open. This is the third event
1.K+ efflux, Repolarization. Fourth event
3.Hyperpolarization, K+ channels close
Explanation:
In resting state, the membrane is negative inside, and K+ concentration is higher than outside. Na+ concentration is higher outside instead.
Sodium influx is responsible for membrane depolarization. It's the event to produce the action potential. When sodium channels are closing, potassium channels open and K+ go outside until repolarization occurs. But now we have both ions in different sides of the membrane, and this can't be stimulated again to produce other action potential. The membrane will remain refractory to respond to the adequate stimulus until ions migrate to their original sites. This is Na+ outside, and K+ inside. This is responsibility of the Na+/ K+ pump, that uses ATP to pump Na+ out, and K+ in. Once both ions had been relocated in the membrane, this is ready to receive a correct stimulus to produce a new action potential.
Answer:
Novobiocin target DNA GYRASE of gram positive bacteria.
Explanation:
Novobiocin is a bacteriostatic(slow down bacteria growth) or bactericidal i.e it kills bacteria , narrow spectrum antibiotics that target DNA GYRASE of gram positive bacteria. It acts by inhibiting the bacteria DNA gyrase hydrolysis thereby by interfering with the metabolic activities of bacteria. It is also a weak catalytic inhibitor of mammalian. Novobiocin inhibit DNA gyrase and topoIV by binding to the ATP pocket of GyrB and ParE, respectively.The Streptomyces strain that produces Novobiocin and it is more effective on gram positive bacteria that gram negative bacteria because gram negative bacteria are resistant to it.
