The DNA will appear uncondensed and restricted to the nucleus. This is because a majority of the cells found in the sample will be in interphase, the longest stage of the cell cycle. Since it is the longest phase in the cell cycle, a majority of cells will be undergoing this phase at any given sample time. It is a point when the cell is undergoing normal cell processes and preparing for replication. During this phase, the DNA is uncondensed, allowing for transcription and giving DNA replication enzymes easy access to the nucleotide sequence.

DNA is condensed into 46 discrete chromosomes and restricted to the nucleus during early prophase, which makes up only a short period of the cell cycle. DNA is never condensed into 23 discrete chromosomes in somatic cells (such as epithelium), since 23 chromosomes would indicate a haploid cell. In humans, haploid cells only exist in the gametes, or sex cells. While prokaryotes have a single circular chromosome floating in the cytoplasm, such structure for a eukaryotic genome is not possible.

The key to this question is to remember the difference between chromosomes and sister chromatids. During the G2 phase the cell has already undergone DNA replication (in the S phase). Each of the chromosomes will therefore have identical sister chromatids. There will be 92 sister chromatids, but only 46 chromosomes. A chromosome is one entity that consists of the two sister chromatids bound together at the centromere.

During the G1 phase, DNA has not yet been replicated and there is only one copy of genetic information. The cell, however, is still diploid and contains information for 46 chromosomes, but only 46 chromatids. The S phase accounts for the duplication of chromatids, but does not change the total number of chromosomes.

Metabolism is the sum of all of the chemical and physical processes in a cell. Cell metabolism refers to any change in the cell.

Homeostasis is the resistance of the cell to change, and is responsible for maintaining a stable environment within the cell and body. Biochemistry is the sum of the chemical processes in the body.

A cell cycle has three crucial checkpoints. The checkpoints function to verify cellular processes and materials that are required for subsequent steps in the cell cycle.

The first checkpoint occurs between the G1 and S phase. The purpose of this checkpoint is to check if the cell is ready for DNA replication. The second checkpoint occurs between the G2 phase and prophase of mitosis (beginning of the M phase). The purpose of this checkpoint is to ensure the completion of replication and the integrity of DNA. The third checkpoint occurs between metaphase and anaphase. This checks if the chromosomes are properly attached at the metaphase plate. All three checkpoints are essential and are irreversible.

For this question we must identify processes that immediately follow a checkpoint. Option I is not correct because it is not preceded by a checkpoint. Option II is correct because sister chromatid separation occurs during anaphase, and anaphase is preceded by the third checkpoint. Similarly, option III is also correct because DNA replication occurs during the S phase, which is preceded by the first checkpoint.

The stages of the cell cycle begin with G1, during which the cell grows and prepares for chromosome replication by synthesizing proteins and cellular structures. The chromosomes do not actually duplicate themselves until the next step, the S phase. After the S phase comes G2, another resting/growth period, and if the cell is properly developed it can then finally enter mitosis. If the cell stops at the G1 checkpoint, it has been arrested before it can enter the S phase and its chromosomes will be unable to replicate.

The three key checkpoints in the cell cycle occur after the G1 phase, before chromosome replication, after the G2 phase, before mitosis, and after metaphase, before chromatids are separated.

G1 (gap 1 phase) is the first stage of the cell cycle. Growth and some preparation for cell division occurs in this stage. If the cell is not preparing to divide then it enters the G0 stage (gap 0 phase): the resting gap stage where neither growth nor division occurs. The S stage (DNA Synthesis phase) comes next and there chromosome duplication occurs. G2 (gap phase 2) is after the S stage and there cell growth continues and everything is checked to make sure the cell can divide. Finally, M stage (mitotic stage) is last and there mitosis occurs and two new daughter cells begin the cell cycle again. Keep in mind that at the end of each stage there are "checkpoints" that the cell needs to pass in order to keep going forward. Cancer occurs when a cell bypasses those checkpoints and continues to replicate without those controls.

The G1 phase is the first stage of interphase. During this period, the cell grows and develops. In order to proceed to the next phase of interphase, the cell must pass the G1 checkpoint. In order for this to happen, cyclin proteins must be present and the proper cellular conditions must occur. If the cell passes the checkpoint it will proceed to the S phase, during which DNA replication occurs. If the cell fails to pass the checkpoint it can enter the G0 phase and become quiescent.

The G2 phase follows the S phase and ends with the G2 checkpoint. This checkpoint determines if the cell will enter mitosis, the M phase.

Interphase alternates with the mitotic phase and accounts for approximately 90% of the cell cycle. During interphase, the cell grows (G1 phase), replicates/synthesizes its chromosomes (S phase), and completes preparation for cell division (G2 phase).

The M phase occurs after the G2 phase and corresponds with mitosis, which is not considered part of interphase.

Histones are nuclear proteins that organize and compact DNA. Histones act as core proteins around which DNA molecules can wrap and form nucleosomes. Since histones are proteins, they are mostly made up of amino acids.

Recall that amino acids are the building blocks of proteins, nucleotides are the monomers of nucleic acids, and monosaccharides are the monomers of carbohydrates. Fatty acids are a common component in lipids.

Cancer cells are not controlled by cyclins and cyclin-dependent kinases, which regulate the cell cycle. They would not proceed through interphase if the system of checkpoints was still in place. The system of chemical signaling is mostly destroyed, preventing the cancer cells from being controlled by surrounding normal cells. Cancer cells, like virtually all body cells, utilize glucose for energy.