Answer:
Certain fossils, called index fossils, help geologists match rock layers. To be useful as an index fossil, a fossil must be widely distributed and represent a type of organism that existed for a brief time period.
Answer:
I think it explains that the DNA molecules are double helix with alenine and thymine paired together
Earthworms have no special respiratory organs. Gases are exchanged through the moist skin and capillaries
Answer:
DNA replication
Explanation:
DNA is the genetic material and serves to store genetic information. The genetic information is transmitted from a parent cell to the daughter cells or from the parent to the progeny by the process of DNA replication.
DNA replication is the process that occurs in the nucleus in eukaryotes and includes the synthesis of new DNA strands using the existing DNA strands as a template. The newly formed DNA molecules are then distributed among the daughter cells during cell division. Thereby, the process of DNA replication ensures that the DNA of the parent generation is carried to the next generation.
For instance, sperms and egg cells in humans carry the DNA of male and female parents respectively to the young one. DNA replication occurs in sperm mother cells and egg mother cells during the formation of sperms and egg cells respectively.