Cp Bio 1: Cell Cycle Quiz 2015

Cytokinesis is the final stage of cell division, where the cytoplasm divides into two daughter cells. During this process, the cell membrane forms a cleavage furrow or a cell plate, which gradually deepens and separates the cytoplasm. This results in the formation of two separate cells, each containing a nucleus and other organelles. The other options mentioned, such as the breakdown of the nuclear membrane, alignment of chromosomes, and separation of sister chromatids, are characteristic of earlier stages of cell division, specifically during mitosis.

Interphase is the longest phase of the cell cycle, consisting of G1, S, and G2 stages. During G1, the cell grows and carries out its normal functions. In the S phase, DNA replication occurs. G2 is the final stage of interphase, where the cell prepares for division. M phase, or mitosis, is not a stage of interphase. It is the phase where the cell divides into two daughter cells.

The stage of mitosis illustrated on the right is metaphase. During metaphase, the chromosomes align along the equator of the cell. This alignment is important for the equal distribution of genetic material to the daughter cells during cell division.

The stage of mitosis illustrated on the right is anaphase. This can be determined by observing the separation of sister chromatids, which are pulled apart towards opposite ends of the cell by the spindle fibers. The chromosomes appear elongated and are clearly divided into two distinct sets. Additionally, the nuclear membrane has disappeared, and the cell is preparing for cytokinesis.

During telophase, the cell membrane starts to contract and pinch inward, creating a cleavage furrow. This furrow is a shallow groove that eventually divides the cytoplasm into two separate cells during cytokinesis. The formation of the cleavage furrow is essential for the completion of cell division in animal cells. It marks the beginning of the physical separation of the two daughter cells and is a crucial step in the process of cell division.

Synthesis is not part of M phase because it occurs during the S phase of the cell cycle. M phase, also known as the mitotic phase, consists of prophase, metaphase, anaphase, and telophase. During M phase, the cell undergoes nuclear division and cytokinesis, resulting in the formation of two daughter cells. Synthesis, on the other hand, is the phase where DNA replication takes place, preparing the cell for division in the subsequent M phase.

The characteristic of G1 phase is cell growth and normal function. This phase occurs after cell division and is a period of active cell growth and metabolic activity. During this phase, the cell increases in size, synthesizes proteins, and carries out its normal functions. It is the first phase of the cell cycle and prepares the cell for DNA replication in the subsequent S phase. The nuclear membrane reforms and DNA replication occur in later phases of the cell cycle.

The image on the right shows a stage of mitosis where the chromosomes have reached opposite poles of the cell and are starting to decondense. This is characteristic of telophase, the final stage of mitosis. During telophase, the nuclear envelope reforms around the separated chromosomes, and the cell begins to divide into two daughter cells.

During metaphase, the chromosomes line up in the middle of the cell. This is a characteristic of metaphase and is an important step in cell division. The alignment of chromosomes in the middle ensures that they are evenly distributed to each daughter cell during the subsequent stages of cell division. It allows for the accurate separation of genetic material and ensures the formation of two identical daughter cells.

During anaphase, sister chromatids, which are identical copies of each chromosome, are pulled apart by the spindle fibers towards opposite poles of the cell. This ensures that each daughter cell will receive a complete set of chromosomes during cell division. The nuclear membrane has already broken down in prophase, and chromosomes lining up in the middle of the cell occurs during metaphase. The splitting of the cytoplasm, known as cytokinesis, occurs after anaphase.

Plant cells form a cell plate instead of a cleavage furrow during cell division. This is because plant cells have a rigid cell wall that prevents them from pinching inwards to form a cleavage furrow like animal cells. Instead, they form a cell plate, which is made up of vesicles containing cell wall materials, that gradually expands and fuses with the existing cell wall to separate the daughter cells.

The stage of mitosis illustrated on the right is prophase. Prophase is the first stage of mitosis where the chromosomes condense and become visible, the nuclear membrane breaks down, and the spindle fibers begin to form. This stage is characterized by the preparation of the cell for division and the organization of the genetic material.

During prophase, the nuclear membrane breaks down, allowing the chromosomes to become visible. This is an important characteristic of prophase as it marks the beginning of mitosis or meiosis. The breakdown of the nuclear membrane allows for the proper separation and movement of the chromosomes during cell division.

G2 phase is the third phase of the cell cycle, following the S phase where DNA is replicated. During G2 phase, the cell continues to grow and prepares for mitosis, the process of cell division. This includes synthesizing proteins and organelles needed for cell division, as well as checking for any errors in DNA replication. The nuclear membrane also reforms during this phase, getting ready for the division of genetic material. Therefore, the characteristic of G2 phase is cell growth and preparation for mitosis.

Telophase is the final stage of mitosis where the nuclear membrane reforms around the separated chromosomes. During telophase, the chromosomes reach opposite poles of the cell and decondense, and a new nuclear envelope starts to form around each set of chromosomes. This process is crucial for the proper division of genetic material and the formation of two daughter cells. Cell growth and preparation for mitosis occur in earlier stages of the cell cycle, while DNA replication takes place during the S phase.

The S phase of the cell cycle is the phase in which DNA replication occurs. During this phase, the cell's DNA is duplicated to prepare for cell division. This ensures that each daughter cell receives a complete set of genetic information. The other options mentioned, such as cell growth and normal function, cell growth and preparation for mitosis, and nuclear membrane reforms, are not specific characteristics of the S phase.

The term used to describe the imaginary plane along which chromosomes line up during metaphase is called the metaphase plate. This is the point in cell division where the chromosomes align themselves along a plane in the middle of the cell, preparing for separation into two daughter cells. The metaphase plate is important for ensuring equal distribution of genetic material to each daughter cell. The other options, cell plate, cleavage furrow, and envelope, are not related to the alignment of chromosomes during metaphase.

Cytokinesis is the stage of the cell cycle where the cytoplasm of the cell divides, resulting in the formation of two daughter cells. In this stage, the cell membrane pinches inward, forming a cleavage furrow in animal cells or a cell plate in plant cells. The given answer "cytokinesis" is correct because the image or illustration provided likely shows the final step of cell division, where the cytoplasm is being divided into two separate cells.

G zero refers to the phase in the cell cycle where cells are not actively dividing or preparing to divide. It is a resting phase where cells can temporarily or permanently exit the cell cycle. During this phase, cells are not undergoing mitosis and are not actively engaged in the process of cell division. Therefore, the cells mentioned in the question that live their entire lives without going through mitosis can be categorized as being in G zero.

Mitosis is the process of cell division, where a single cell divides into two identical daughter cells. During mitosis, the nucleus of the cell also divides, ensuring that each daughter cell receives an identical copy of the genetic material. Therefore, the correct answer is "Division of the nucleus."