In the beginning <span>of the RNA strand as a cap, a modified guanine nucleotide is added. After this, there is a removal of those segments of the RNA strand that do not actually code for the protein. And those RNA’s segments that do code for the protein are reconnected. And forking a tail, extra adenine nucleotides are added to the end of the RNA strand. The mRNA or messenger RNA which is already completed will then leave the nucleus. This whole process is called the RNA processing. Before the RNA copy of a protein encoding can be transported out of the nucleus and translated into protein, it must be first be modified in several ways. A precursor of mRNA, pre-mRNA is the primary transcription product of a gene. </span>
<span>In liver, the most intensively studied transmembrane and intracellular signal transduction pathways are the Janus kinase signal transduction pathway, the mitogen-activated protein kinases signal transduction pathway, the transforming growth factor β signal transduction pathway, the tumor necrosis factor α signal transduction pathway and the recently discovered sphingolipid signal transduction pathway. All of them are activated by many different cytokines and growth factors. They regulate specific cell mechanisms such as hepatocytes proliferation, growth, differentiation, adhesion, apoptosis, and synthesis and degradation of the extracellular matrix. The replication cycle of hepatitis C virus (HCV) is intracellular and requires signal </span>
Answer: D. All living cells come from other living cells.
Explanation:
A is incorrect because organisms like bacteria and amoebas are unicellular, or have 1 cell.
B is incorrect because cells are specialized: nerve cells and muscle cells do not share the same function.
C is incorrect because inanimate objects are not alive and do not have cells.
D is correct because cells reproduce by mitosis, creating copies of themselves.
