<span>the time when the sun crosses the plane of the earth's equator, making night and day of approximately equal length all over the earth </span>
Answer: Keystone species
Explanation: A keystone species is a species which occupied a niche so central in the ecosystem that it has a disproportionately large effect on its environment and other species in it.
The coral's function in its ecosystem is so vital that if you were to remove it, the entire community would be drastically altered beyond recognition.
The coral serves as the base structure of its ecosystem.
That is to say that many corals are hermatypic(they form reefs). This reef serves as the environmental structure of the Coral's ecosystem. Built in and around it is a very biodiverse biotic environment. The coral not only serves as a hiding place and habitat for many marine organisms including fish, clams, lobsters, etc. It serves as resting place for larger animals like turtles and also serves as hunting sites for other animal species.
The most common way of determining a keystone species, is to see what happens when that species is removed from the ecosystem. Coral have shown to be so central to their ecosystem that the bleaching of coral reefs due to tourism and climate change causes a massive loss to biodiversity. And this is quite significant as reefs are the most biodiverse marine habitats.
Answer:
First, it transports blood with oxygen and nutrients to cells all over the body. Second, it picks up waste products from the cells to be transported out of the body, and it takes the deoxygenated blood back to the lungs so it can regenerate.
Answer:
2. It is made of sandstone which is very porous and is easily penetrated by rainwater
Explanation:
The White House is made of gray-colored sandstone that is brought from quarry in Aquia, Virginia. The north and south porticos of white house building are constructed with red Seneca sandstone brought from Maryland. These sandstones are porous in which rainwater is easily penetrated in it that cause damage to the white house building so it is concluded that the building is made of porous sandstone.
How many places are there for electrons in the second shell of an atom? The answer is C) 8 electrons