15. if nearly all the cells in the organism
have identical dna, how do cells
differentiate? (hint: transcription
factors)

This process is called differentiation.

We know that during sexual reproduction, the mating results in fertilization between sperms and ova with production of zygote. This zygote is a single cell, which divides for thousands of time to produce a whole multicellular organism.

Each and every cell which is produced from the embryo have the same DNA and the same number of genes. But during the intrauterine life of the embryo, some cells start expressing some gene while others the different genes. This paves the way for organ differentiation and tissue differentiation. So the process by which the different cells of a multicellular organism expresses different gene inspite of having same DNA is called Differentiation.

the water is warmed up by the sun and then it evaporates into the atmosphere. the sunlight warms the water by its heat. water is then cooled down and condensation takes place. the water then finally returns back to the earth by the process of precipitation in the form of rain or ice.

explanation:

the answer is c. it will give up it's valence electron to the other atom.