Answer:
1. coevolution
2. abiogenesis
3. Endosymbiont Theory
4. It's estimated that over 99 percent of the species that have existed on Earth at some point in time are extinct today.
5. Coevolution implies that the evolution of one species is dependent on and works in relation to the evolution of another species. This may cause positive or negative impacts and could be beneficial to both organisms or only to one.
6. This theory states that the first building block of life that allowed for reproduction of organisms was the development of self-replicating RNA. This hasn't been able to be fully demonstrated in any science experiment but is based on the idea that there are RNAs that can catalyze biochemical reactions on their own without proteins.
7. This process points to the development of structures through the envelopment of smaller cells that perform specific functions. This is how eukaryotic cells evolved from prokaryotic cells.
8. This experiment was important because it showed that, in the right primordial soup, organic compounds could develop from inorganic compounds.
Explanation:
penn foster
Answer:
Mantle plumes that form hotspots are thought to be relatively stationary whereas the overlying tectonic plates typically are not. Thus, as a plate moves over the location of a plume eruption, it carries successively older volcanoes with it.
Answer:
9600 cm/min
Explanation:
Well, the circumference of the flywheel is 2π×the radius(16 cm). That's how far the spot moves in one revolution.
10 radians per second divided by 2π is the number of revolutions per second.
So multiply that times the circumference and that's the distance the point has traveled.
let the linear speed of the spot be v
therefore, v= 160×60= 9600 cm/min
Answer:
The correct answer is ''loss of acetylcholine receptors in the end-plate membrane.''
Explanation:
Myasthenia gravis represents a human autoimmune disease. The neuromuscular junction abnormalities that occur in this disease are due to antibody-mediated processes. A reduction in the number of functional acetylcholine receptors on the postsynaptic membrane was established to contribute to the physiological abnormalities of myasthenia gravis. The reduction in receptors is due to immunological alterations directed against the acetylcholine receptor. Normally, when acetylcholine binds to its receptor, it opens allowing the rapid entry of cations, especially sodium. With this, the depolarization of the postsynaptic region of the muscle fiber occurs. Although acetylcholine is normally released in myasthenia gravis, it is not capable of causing an action potential in the muscle sufficient to initiate or weaken contraction. In patients with myasthenia gravis, failure to activate muscles is responsible for myasthenic fatigue. Most patients have elevated serum titers of antireceptor antibodies, which in turn accelerate receptor degradation.
