New News Biology #3

Cell Differentiation

Highly Specialized Cells:

Human Sperm; carries the father’s DNA

Human Egg; bigger in size, carries mother’s DNA and the nutrients needed for an embryo to grow

Note: Both the sperm and the egg each only have half of the required DNA for a normal functioning cell, so that when the two are joined, a new cell is created (the stem cell)

The Stem Cell (created when the sperm and egg join together)

Characteristics: Completely undifferentiated; has the ability to differentiate into any cell type (e.g. muscle cells, nerve cells, and more)

Types of Human Stem Cell:

Embryonic; potential for differentiation into any type of cell (could be used to cure diseases)

Adult; found in the bone marrow, they can only produce blood cells (possible to be used in blood transplants)

note: stem cell research is banned in many countries considering ethical issues