Answer:
The lithosphere is the solid, outer part of the Earth. The lithosphere includes the brittle upper portion of the mantle and the crust, the outermost layers of Earths structure. It is bounded by the atmosphere above and the asthenosphere (another part of the upper mantle) below. Although the rocks of the lithosphere are still considered elastic, they are not viscous.
Explanation:
It is often useful for scientists to study a population of cells that are all at the same stage of the cell cycle.
<h3>Why the discovery of cyclins and cdks was enabled?</h3>
The discovery of cyclins and cdks was enabled by studying frog eggs that divided synchronously after fertilization; extracts from the embryos were thus representative of the cell-cycle stage at which the extract was made.
Researchers have devised means to synchronize asynchronous populations of cultured cells. for example, serum starvation deprives cells of mitogens and blocks cells in the g0/g1 phase of the cell cycle.
Therefore, It is often useful for scientists to study a population of cells that are all at the same stage of the cell cycle.
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<span>Nondisjunction is the failure of homologous chromosomes or sister chromatids to seperate properly during cell division.</span>