A model of a globe is a physical model. The limits are that the solar system is too big to be seen all at once. From the Tennessee science textbook, "Many years ago, scientists thought that Earth was the center of the universe and the sky was a blanket that covered the planet. Later through the observation, it was discovered that the objects you see in the sky are the sun, the moon ,stars, and other planets. This new model explained the solar system differently.
The number of mitochondria per cell varies widely; for example, in humans, erythrocytes (red blood cells) do not contain any mitochondria, whereas liver cells and muscle cells may contain hundreds or even thousands. The only eukaryotic organism known to lack mitochondria is the oxymonad Monocercomonoides species.
Answer:
Reproductive isolation occurs faster in deep-water shrimp than shallow-water shrimp.
Explanation:
Though in the same territory, the blockage caused by the isthmus would quickly and permanently isolate shrimps living in the deeper parts of the water, thus making them unable to breed. This situation would then caused lack of gene flow within the deep-water shrimps , and the emergence of new species that are genetically different (diverge) from one another
The shallow-water shrimp, on the other hand, experience minimal isolation due to the shallowness of water, and could still breed with one another. Thus, they experience a relatively lower reproductive isolation
Density-dependent limiting factors cause a population's per capita growth rate to change—typically, to drop—with increasing population density
