The Development of the Embryo

As we are starting to explore a new area, the stem cells and the ethics around them, I'll answer some questions about the video "The Embryo takes shape" to have a better knowledge of this biological process.

1) What directs the sequence of events that turn a blob of cells into an embryo with specialized tissues and organs?
It's mainly determined by the genes and by the three layers created in gastrolation. The lower layer becomes the lungs, liver and digestive tract, the middle layer turns into the heart, muscles, bones and blood, while the top layers develops into the nervous system, skin and hair.

2) The narrator says that “cells talk to each other.” What does that mean?
It means that they can communicate to each other by chemical messages, which activate some specific gens in the nearby cells.

3) How do cells in different parts of the embryo become different kinds of cells and organs?
It depends on the ADN, the gens activated in each cell and the embryo layers explained in question 1.

4) What kinds of proteins are found in different cells and organs?
Collagen - Skin, tendons and bones.
Carrington - Hair.
Crystalline - Lens of the eyes.
Actin and myosin - Muscle fibers.
Hemoglobin - Carries oxygens from lungs to body.

5) What tells the cells which kinds of proteins to make?
The groups of genes activated in each cell.

6) What is the relationship between DNA, genes, and the proteins that are produced in cells?
They are all connected. The DNA is the genetical information in your cells, and genes are very small sections of these code. The genes, activated by molecules, determine which proteins are produced in each cell. Proteins are the molecules that build our bodies.