Specialised Cells & Stem Cells

What is cell differentiation?

The process by which a cell changes to become specialised for its job. As a cell differentiates, it acquires different sub-cellular structures to carry out a specific function.

Give three examples of specialised animal cells and their adaptations.

• Sperm cell: Tail for swimming, many mitochondria for energy, acrosome with enzymes to penetrate the egg.

• Nerve cell: Long axon to carry impulses over distances, dendrites to connect to other cells.

• Muscle cell: Many mitochondria for energy, protein fibers that contract.

What is the difference between Embryonic and Adult Stem Cells?

Embryonic stem cells can differentiate into any type of body cell (totipotent/pluripotent). Adult stem cells (found in bone marrow) can only differentiate into a limited number of cells, such as blood cells.

What are the benefits and risks of Therapeutic Cloning?

• Benefit: Embryo produced has the same genes as the patient, so stem cells aren't rejected.

• Risk: Potential transfer of viral infections and ethical/religious objections to using human embryos.