<span>I suspect this question should read "How long does a red blood
cell live." A red blood cell lives for between 100 and 120 days. It
takes 7 days for a new red blood cell to develop from stem cells. Stem
cells are similar to base cells. They can also be seen as a general
template from which specialized cells are made. Stem cells can be taken
from a newborn baby's umbilical chord or extracted from an adult blood
donor's blood.</span>
All galaxies have a dense core of stars. Spiral galaxies, however, have arms that are often visible. There are two kinds of spiral galaxies: barred, where there appears to be a line running from arm to arm through the core, and <span>ordinary, where there is no bar. @Badbunnyhunny</span>
The saliva has enzymes that start to break down food using the lock and key system.The teeth chews the food and begins mechanical break down of food
Answer:
Eukaryotes are found in plants, animals, fungi, and protists
Phages are a positive use of viruses