What is the process by which DNA makes a copy of itself before cell division?

The process by which DNA makes a copy of itself before cell division is known as replication. This is a crucial step in the cell cycle, ensuring that each new cell receives an identical set of DNA during cell division.

During replication, the DNA double helix unwinds, and each strand serves as a template for synthesizing a new complementary strand. DNA polymerase enzymes play a key role in adding nucleotides to the growing strands, ensuring that the genetic information is accurately copied. This process ultimately results in two identical DNA molecules, each consisting of one original strand and one newly synthesized strand, a method referred to as semi-conservative replication.

The other processes mentioned have different functions: transcription refers to the synthesis of RNA from a DNA template, translation is the process of synthesizing proteins from RNA, and photosynthesis involves converting light energy into chemical energy in plants. These processes do not involve the direct copying of DNA, which is why they are not the correct answer in this context.