Animal cells contain dna enclosed in the nucleus
<span>All four nucleotides (adenine, guanine, thymine, cytosine) are synthesized in the liver. The nucleotides can be synthesized de novo or recycled through salvage pathways. The synthesis occurs in the cytoplasm of the cell, not within a specific organelle. The components which are used for the nucleotide synthesis are derived from biosynthetic precursors of carbohydrate and amino acid metabolism, and from ammonia and CO2.</span>
there was no following stated.
Answer:
The endosymbiotic theory
Explanation:
Protists are the multicellular organisms which possess characteristics of both the prokaryotes and eukaryotes.
The protist can derive nutrition by either heterotrophic mode or photoautotrophic mode. This variation could exist within the same genus and same species.
This variation could be explained with the endosymbiotic origin of the organisms as some species could engulf the photosynthetic bacteria whereas some could have engulfed the chemosynthetic bacteria.
This can be observed in the green and red algae which depend on a different mode of nutrition belonging to the same group.
Thus, the endosymbiotic theory is correct.