Is it plant fertilization of human fertilization?
Water had the capability to hold up the thin overhang of the underground.
When water is depleted, there is nothing to support this overhang, which eventually led to the formation of sinkholes.
As for the collective behavior, it's all because of the scarcity. Water is one of human's basic needs to survive. When water is scarce, this will force the people to compete with one another to obtain it, which will cause the behavior
Answer:
carbon dioxide- burning of fossil fuels
fluorinated gases- industrial processes
methane- production and transport of oil and natural
gas
nitrous oxide- agricultural and industrial activities
Explanation:
Greenhouse gases are gaseous components that induces greenhouse effect. This means that due to their structural ability to trap heat energy in the atmosphere, they contribute to the global warming effect on the Earth. However, this greenhouse gases are produced in large amounts as a result of the day-to-day anthropogenic activities. The following are the greenhouse gases and how they are produced.
Carbondioxide (CO2)- Carbondioxide is the most common and important greenhouse gas. It is generated via natural processes like respiration but also produced when fossil fuels e.g coal, petroleum etc. are burned.
Fluorinated gases- This is another greenhouse gas caused by activities of man. Fluorinated gases are produced in industries during the production of certain products.
Methane- Methane is a gaseous hydrocarbon and the principal constituent of natural gas. Therefore, the production and transportation of oil and natural gases can lead to the escape of methane into the atmosphere.
Nitrous oxide- Nitrous oxide is an oxide of nitrogen. It is mainly produced via agricultural processes such as nitrification and denitrification or use of fertilizers etc. and also industrial actions.
Answer:
The theory of evolution by natural selection, first formulated in Darwin's book "On the Origin of Species" in 1859, is the process by which organisms change over time as a result of changes in heritable physical or behavioral traits. Changes that allow an organism to better adapt to its environment will help it survive and have more offspring.
Evolution by natural selection is one of the best substantiated theories in the history of science, supported by evidence from a wide variety of scientific disciplines, including paleontology, geology, genetics and developmental biology.
The theory has two main points, said Brian Richmond, curator of human origins at the American Museum of Natural History in New York City. "All life on Earth is connected and related to each other," and this diversity of life is a product of "modifications of populations by natural selection, where some traits were favored in and environment over others," he said.
More simply put, the theory can be described as "descent with modification," said Briana Pobiner, an anthropologist and educator at the Smithsonian Institution National Museum of Natural History in Washington, D.C., who specializes in the study of human origins.
The theory is sometimes described as "survival of the fittest," but that can be misleading, Pobiner said. Here, "fitness" refers not to an organism's strength or athletic ability, but rather the ability to survive and reproduce.
Answer:
- Both organelles present their genetic material.
- Both organelles divide by binary fission
- Both organelles present a double membrane, the internal one looks identical to the bacterial membrane, while the external membrane looks like the eukaryotic one.
- In the internal membrane are placed the energy centers, just as it occurs in bacterias membrane.
- The sizes of the organelles are similar to the size of some procaryotes
Explanation:
The endosymbiotic theory essentially states that some organules of the eukaryotic cells, such as mitochondria and chloroplasts, were once free-living bacteria. Probably, these organisms must have been phagocytized but not digested by another cell. These bacteria were able to adapt to their host, establishing a bond of dependence among each other.
Both organelles have many similarities with other free-living bacteria. For this reason, the theory states that chloroplasts derivate from cyanobacteria (because they both absorb sunlight, store the energy in ATP, and produce organic molecules) and that mitochondria derivate from rickettsias (because they produce ATP in the same way, by using the Krebs Cycle and Oxidative Phosphorylation).
This theory is supported by a few characteristics of the chloroplasts and mitochondria that suggest that they once were free cells. For example,
- Both organelles present their genetic material. This DNI is independent of the cells´ DNA, is bi-catenary and circular, identical to the bacterial DNA, and very different from the one of the eukaryotic cells.
- Both organelles divide by binary fission, not by mitosis, and can synthesize their ribosomes and organelles.
- Both organelles present a double membrane, a characteristic that reinforces the idea of being phagocyted. The internal membrane looks identical to the bacterial membrane, while the external membrane looks like the eukaryotic one.
- In fact, in this internal membrane are placed the energy centers, just as it occurs in bacterias membrane.
- Finally, the sizes of the organelles are similar to the size of some procaryotes