D. ice core samples for the arctic and anarctic
Answer:
no
Explanation:
a furrow is a trench dug by a plow or (insert word for the name of a garden tool that looks like a naughty word) for planting seeds or to carry water for irrigation.
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.
Answer:
The correct answer is -
1. protein synthesis or central dogma
2. leads to changes in the structure by changing in the codes which results in a decrease or loss of function.
Explanation:
1, Protein is made from the information coded in DNA base sequences by the two process protein synthesis that is also called central dogma. The two-process involve in this are transcription involves encoding the information present in DNA by mRNA molecule that codes the information in complementary sequence to DNA. which is then moved out of the nucleus and perform the translation with help of tRNA and ribosome to code the amino acid with help of triplet codes present in mRNA. These amino acids chain are called proteins.
2. Mutations can lead to change in the base sequences or deletion of the base which affects the structure of the protein and also leads to changes in an encoded protein or to a decrease or complete loss in its function or expression. Mutation can damage the cell or organism as it affects the gene expression of all cells of organisms.
