Complete question:
This model of the cell cycle includes two arrows that each represent a process in the cycle.
What do the two arrows represent?
A. Arrow 1 represents prophase, and arrow 2 represents interphase.
B. Arrow 1 represents mitosis, and Arrow 2 represent meiosis.
C. Arrow 1 represents interphase, and Arrow 2 represents mitosis.
D. Arrow 1 represents meiosis, and Arrow 2 represents prophase.
(You will find the cycle in the attached files)
C. Arrow 1 represents interphase, and Arrow 2 represents mitosis.
Explanation:
When we talk about the whole cell cycle we are referring to the interphase and the cell division (mitosis or meiosis).
Interphase: Represented in the cycle 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 duplicate too. 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 apparatus 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 occurs the DNI replication process. At this point, also occurs the synthesis of histones and other associated proteins. This is the only stage where the DNI molecule is replicated.
•G2 stage is the final one before the cellular division. Here begins the slow process of DNI condensation. Duplication of centrioles completes. Structures such as spindle fibers are 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 cell separates. Mitosis is divided into four phases (these phases are shown in the cycle with different gray color tones). In the prophase, it occurs chromosomes condensation and nuclear membrane breaks. During the metaphase, fibers of the spindle apparatus capture chromosomes and take them toward the center of the cell, to the equatorial plane, where they line up. Each chromatid joins with a microtubule of opposites poles. Sister chromatids are held together until they reach the Anaphase, during which other enzymes are activated to break the bonds and separate the chromatids, which migrate to the opposite poles. In telophase, the duplicated chromosomes are already in the corresponding poles, and the nuclear membrane forms again in each pole. Finally, occurs cytokinesis.
