Cells, germ: The eggs and sperm are the germ cells: the reproductive cells. Each mature germ cell is haploid in that it has a single set of 23 chromosomes containing half the usual amount of DNA and half the usual number of genes.
Except for the eggs and sperm, each cell in the human body — there are 100 trillion cells in each of us — contains the entire human genome, all the genetic information necessary to build a human being, and this information is encoded within the cell nucleus in 6 billion base pairs, subunits of DNA, packaged in 23 pairs of chromosomes, one chromosome in each pair coming from each parent.
The germs cells — the eggs and sperm — are thus notable exceptions to the usual rules governing chromosomes, genes, and DNA.
- Cells, reproductive
Cells, reproductive: The eggs and sperm are the reproductive cells. Each mature reproductive cell is haploid in that it has a single set of 23 chromosomes containing half the usual DNA amount. Except for the eggs and sperm, each cell in the human body — there are 100 trillion cells in each of us — […]
- Human genome
Human genome: All the genetic information in a person. The human genome is made up of the DNA in chromosomes as well as the DNA in mitochondria.
McGraw-Hill Professional, 2008.
A spreading bacterial infection underneath the skin surface characterized by redness, warmth, swelling, and pain. Cellulitis commonly appears in areas where there is a break in the skin.
Celsus: (1st century A.D.) Aulus (Aurelius) Cornelius Celsus. Roman encyclopedist whose only surviving work, De Medicina, was rediscovered and printed early in the Renaissance and became influential. His four classical signs of inflammation — calor, dolor, rubor, and tumor (heat, pain, redness, and swelling) — are still useful today.