Answer:
Cell–cell interaction refers to the direct interactions between cell surfaces that play a crucial role in the development and function of multicellular organisms. These interactions allow cells to communicate with each other in response to changes in their microenvironment.
Explanation:
Flagellum, plural flagella, hairlike structure that acts primarily as an organelle of locomotion in the cells of many living organisms. Flagella, characteristic of the protozoan group Mastigophora, also occur on the gametes of algae, fungi, mosses, slime molds, and animals.
Flagellum Definition
A flagellum is a microscopic hair-like organelle used by cells and microorganisms for movement. The word flagellum in Latin means whip, just like the whipping motion flagella (plural) often use for locomotion. Specialized flagella in some organisms are also used as sensory organelles that can detect changes in temperature and pH.
The correct answer is option A, S Phase - DNA Replication
The DNA replication begin at the S phase of the cell cycle. In this phase, the cell grows and prepare itself for the DNA replication while the other components such as centro some undergo replication. The S phase occurs during the inter phase and the genetic material duplicates itself before entering the mitosis and meiosis cell division in the next stage.