Its renewed again and again by natural water cycle
The acidic environment of the lysosome and the lysosomal enzymes detach the ligands from their receptors.
Receptor-mediated endocytosis is a process in which cell surface receptors are employed for transporting substances such as proteins, hormones, and metabolites from extra-cellular matrix into the cells. Receptor-mediated endocytosis usually occurs through clathrin (a type of protein)-coated pits and vesicle and it allow only the receptor-specific substances to enter the cell. Under this process, molecule binds to protein receptors after which the receptor molecule moves to clathrin coated pits and vesicle. The cell membrane then folds inwards and there is fusion of a coated vesicle. After this, the ligands are detached from their receptors.
aeorbic respiration occurs in the mitochondria
Monoploid organisms reproduce asexually since they need to transmit all of their genetic material to their offspring. Diploid organisms, have 2 copies of their genetic material that differ slightly in their genes. Since the progeny gets half of the DNA from each parent, we have that new combinations can emerge; for example, if the mother is AA for some allele and the father aa, their offspring will be Aa, a new genotype. This might have different implications (for example, the recessive gene for thalassemia also provides resistance to malaria). Finally, during meiosis, there is also an event called crossover that increases the genetic variation of the offspring.
