Answer:
Mitosis only
Explanation:
Mitosis and meiosis are both types of cell division. Mitosis allows cells to proliferate for growth and repair. So this is how skin cells form new cells.
Meiosis is a type of cell division specific to reproduction. It forms the gametes, which are the egg and sperm. It generates haploid cells that fuse via fertilization to create a zygote.
Answer:
Changes in gene expression
Explanation:
This phenomenon is the result of changes in gene expression. That means, how the information in the DNA is used by the cell. The genes that are active in the cells of the brain will be very different from the genes that are active in the cells of the bone marrow.
These patterns of gene expression are different for each cell, and dictate the identity of that cell. Gene expression patterns are controlled by a variety of factors in the cell that allow tissue-specific expression, such a transcription factors.
This can also be facilitated by another layer of regulation called epigenetics, which literally means "on top of" genetics, and refers to modifications of DNA (and the proteins around it), that can reflect and influence the activity of the genes within.
The vapor rises until it reaches a low enough temperature and pressure to condense water vapor into water droplets and form a cloud. When vapor condenses into liquid or solid particles, it loses some of its energy to the air.
Hope this helps