About the question:
You will find the model of the cell cycle in the attached files
Answer:
A. Arrow 1 represents interphase, and Arrow 2 represents mitosis.
Explanation:
When we talk about the cell cycle, we refer to the interphase and the cell division (mitosis or meiosis).
Interphase: Represented by arrow 1.
The interphase is the previous step before mitosis occurs. The interphase is conformed of the G1, S, and G2 stages.
• During the G1 stage, it occurs a high intense biochemical activity. The cell duplicates its size, and the organelles and other molecules and cytoplasmatic structures also double. Some structures, such as microtubules and actin filaments, are synthesized from zero. The endoplasmic reticulum increases in size and produces a membrane for the Golgi complex and vacuoles, lysosomes, and vesicles. During this stage, the pair of centrioles separate, and each centriole duplicates. Mitochondria and chloroplasts also replicate.
• During the S stage, the DNI replication process occurs. This is the only stage in which the DNI molecule replicates. The synthesis of histones and other associated proteins also occurs.
• G2 stage is the interphase last step. DNI molecule begins to slowly condensate. The centrioles duplication process completes. The spindle fibers get assembled.
Once the whole interphase is completed, mitosis occurs.
Mitosis: Represented in the cycle by arrow 2.
Mitosis is a process by which, from a diploid somatic cell (2n), two daughter diploid cells (2n) are produced. During mitosis, the whole-cell first duplicates and then separates. Mitosis is divided into four phases (these phases are shown in the cycle with different gray color tones). During prophase, chromosomes condensate, and the nuclear membrane breaks. During the metaphase, fibers of the spindle apparatus take chromosomes toward the equatorial cell plane, where they line up. Sister chromatids are holden together until they reach the Anaphase, during which specialized enzymes break the bonds between chromatids and separate them. Each chromatid migrates to one of the poles. In telophase, the new chromosomes are already in the corresponding poles, and the nuclear membrane forms again in each pole. Finally, cytokinesis occurs.
