Table 3.

A section of the MIT institutional BCF

6. Cell are created from other cells.

6-1. Cells formation by spontaneous generation has never been observed. See 3-2-1.

6-2. As a result of cell division, one cell becomes two.

6-2-1./3-1-1. Before a cell divides, all of its machinery is duplicated.

6-2-2. When eukaryotic cells divide, DNA replication followed by chromosomal segregation in mitosis (2n → 4n → 2n) ensures that the daughter cell has the same genetic information as the mother cell.

6-2-3. The complementary base-pairing of DNA molecules allows for a built-in duplication mechanism. See 9-1-3.

6-2-3-1. Two molecules of DNA are created from one, by semiconservative replication.

6-2-3-2. Each of these new molecules goes to a daughter cell. Therefore, one mother cell gives rise to two daughter cells.

6-2-4. Prior to cell division, all essential cellular machinery is duplicated and segregates into future daughter cells. See 3-1-1/6-2-1.

6-3. In sexual reproduction, two gametes join to form a zygote.

See 5-6, 10-1, 16-1-3.

6-3-1. Each gamete carries half the genetic complement of a cell. See 10-1-3.

6-3-1-1. A gamete carries a haploid set of chromosomes. See 10-2-2.

6-4. One cell division can give rise to two cells that will differentiate into two distinct cell types, serving two distinct functions.

6-4-1. Differentiation usually involves the selective reading of a genome rather than a change in the sequence of the genome. See 7-4, 8-2, 11-2-1, 12-7-1, 14-1, 14-1-2, 14-3-1.

6-4-1-1. Two cells that result from one division, and have the same genetic material can have different morphology and behavior due to differentiation—expressing a different set of genes to perform a different function in the organism. See 12-7-1.

6-4-2. Terminally differentiated cells (that are capable of division) can only give rise to cells of the same type as self.

6-4-3. In multicellular organisms, pluripotent (stem) cells have the potential to differentiate into many different cell types.

6-4-3-1. Whole animal cloning seeks to create the original pluripotent cell—an embryo, using the nucleus of a differentiated cell. See 13-3-1-6.

Cross-references to other sections of the BCF after several of the concepts.