AP BIOLOGY

Detailed explanation-1: -A multicellular organism develops from a single cell (the zygote) into a collection of many different cell types, organized into tissues and organs. Development involves cell division, body axis formation, tissue and organ development, and cell differentiation (gaining a final cell type identity).

Detailed explanation-2: -The fertilized cell is a zygote. The zygote undergoes mitosis to form two identical cells that remain attached. This takes place about 36 hours after fertilization. Mitosis then occurs more frequently.

Detailed explanation-3: -In the zygotic life cycle, the zygote is the only diploid phase. After fertilization the zygote undergoes meiosis to produce haploid cells. The cells undergo mitosis to either increase in number or grow into a haploid multicellular organism. Some haploid cells develop into gametes by mitosis.

Detailed explanation-4: -A zygote is the cell that forms from the fusion of sperm and eggs during fertilization. Each sperm and egg are haploid and when they fuse to form the zygote their genetic material combines and forms a diploid zygote. The zygote then goes through mitosis, the process of cell division.

Detailed explanation-5: -The result of karyogamy is the formation of a diploid cell called the zygote or zygospore. This cell may then enter meiosis or mitosis depending on the life cycle of the species.