The Precambrian era envelopes the major bulk of the history of the Earth, beginning from the creation of the planet approx 4.5 billion years ago and terminating with the origination of composite, multicelled forms of life approximately 4 billion years after.
The Precambrian refers to the earliest of the geologic ages that are signified by the distinct layers of sedimentary rock. The Earth was about more than six hundred million years old when life started. The planet had cooled down from its native molten state, creating a solid crust and oceans formed by water vapor in the atmosphere.
At about three billion years ago, the atmosphere of the Earth was virtually devoid of oxygen. At approximately 2.4 billion years ago, oxygen was discharged from the seas as a waste product of photosynthesis by cyanobacteria. The levels of the gas slowly raised, attaining about 1 percent around two billion years ago.
Approximately 800 million years ago, the levels of oxygen attained about 21 percent and started to breathe life into more composite species. The oxygen-rich ozone layer was also created, protecting the surface of the Earth from the harmful solar radiation.
The large-scale ocean-atmosphere climate interaction linked to a periodic warming in sea surface temperatures across the central and east-central Equatorial Pacific is what is used to describe an El Niño, so I’m guessing this is what is associated with it.
Answer:
fertilization is the process of fusion of gametes from two parents. gametes are produced as a result of meiosis in which crossing over and recombination produces new combinations of genes and sometimes mutations are also occur which also leads to development of unique characteristics.
this is the main reason that kids from same parents are genetically unique.
Explanation:
Answer:
Water moves by gravity into the open pore spaces in the soil, and the size of the soil particles and their spacing determines how much water can flow in. Wide pore spacing at the soil surface increases the rate of water infiltration, so coarse soils have a higher infiltration rate than fine soils.
How does soil particle size affect permeability?
But permeability is a different thing. It increases as particle size increases. By definition, permeability is a MEASURE OF EASE with which fluids will flow though a porous rock, soil or sediment. ... That means capillarity increase as particle sizes decreases.
