Cell Cycle & Mitosis Quiz 10/28/2016

Mitosis is a process of cell division in which a single cell divides into two identical daughter cells. It consists of four stages: prophase, metaphase, anaphase, and telophase. In prophase, the chromatin condenses into chromosomes and the nuclear membrane breaks down. During metaphase, the chromosomes line up in the middle of the cell. Anaphase is characterized by the separation of sister chromatids and their movement towards opposite poles. Finally, in telophase, the chromosomes reach the poles, the nuclear membrane reforms, and the cell starts to divide. Therefore, the correct answer is 4.

During metaphase, the chromosomes line up along the middle of the dividing cell. This is a crucial step in mitosis as it ensures that each daughter cell receives an equal number of chromosomes. The chromosomes align at the metaphase plate, which is a region in the middle of the cell. The alignment of chromosomes in metaphase allows for the proper separation of genetic material during the subsequent phase of mitosis, anaphase.

Cells spend most of their time in interphase. This is the phase in the cell cycle where the cell grows, carries out its normal functions, and replicates its DNA in preparation for cell division. During interphase, the cell is not actively dividing, but rather preparing for the next phase, which is mitosis. In mitosis, the cell undergoes division to produce two identical daughter cells. Therefore, interphase is the phase where the cell spends the majority of its time, as it is necessary for normal cell growth and functioning.

During the S phase of the cell cycle, DNA replication takes place. This is when the DNA in the cell is copied, resulting in two identical copies of each chromosome. The S phase is a critical step in the cell cycle as it ensures that each daughter cell receives a complete set of genetic information. The G1 and G2 phases are involved in cell growth and preparation for DNA replication, while cytokinesis is the final stage of the cell cycle where the cell divides into two daughter cells. Therefore, the correct answer is S phase.

The cell cycle consists of two main stages: interphase and mitosis. Interphase is the longest stage where the cell grows, carries out its normal functions, and replicates its DNA. Mitosis is the stage where the cell's nucleus divides into two identical nuclei, followed by cytokinesis, where the cell's cytoplasm divides. Therefore, the correct answer is interphase and mitosis.

Centrioles are responsible for producing spindle fibers during cell division. Spindle fibers are necessary for the movement and separation of chromosomes during mitosis or meiosis. They form a structure called the mitotic spindle, which helps in the proper alignment and distribution of chromosomes to the daughter cells. The centrioles are located near the nucleus and play a crucial role in organizing the microtubules that make up the spindle fibers. Therefore, the correct answer is centrioles.

The first phase of mitosis is called prophase. During prophase, the chromatin condenses into visible chromosomes, the nuclear envelope breaks down, and the spindle fibers begin to form. This phase marks the beginning of the process of cell division and prepares the cell for the subsequent stages of mitosis.

The protein p53 is known to inhibit cell division, which is the process of mitosis. Mitosis is the division of a cell into two identical daughter cells, and it plays a crucial role in growth, development, and tissue repair. By stopping mitosis, p53 can prevent cells from dividing and potentially halt the growth of tumors or prevent the formation of abnormal cells.

The correct order is cell grows, DNA replication, cell prepare for division, division. This order makes logical sense in the context of the cell cycle. First, the cell needs to grow in size to accommodate the upcoming division. Then, DNA replication occurs to ensure that each daughter cell receives a complete set of genetic material. Next, the cell prepares for division by organizing its components and ensuring that everything is in place. Finally, the division occurs, resulting in the formation of two daughter cells.

Chromatin refers to the uncoiled and spread out form of DNA in a cell nucleus. During interphase, when the cell is not dividing, the DNA is in the form of chromatin. It allows the DNA to be accessible for transcription and replication. Chromosomes, on the other hand, are condensed and tightly coiled structures formed from chromatin during cell division. Chromatids are the two identical copies of a replicated chromosome that are joined together by a centromere. Centromeres are the regions that hold the sister chromatids together. Therefore, the correct answer is chromatin.

Cleavage furrows form in animal cells during cell division. This process, known as cytokinesis, occurs after the chromosomes have separated and involves the pinching of the cell membrane to create two separate daughter cells. In contrast, plants do not form cleavage furrows but instead form a cell plate that divides the cell. Bacteria do not have a membrane-bound nucleus and undergo a different process of cell division called binary fission. Therefore, the correct answer is animal cells.

During anaphase, the sister chromatids, which are identical copies of each other, are pulled apart and move towards opposite ends of the cell. This is achieved by the shortening of the microtubules attached to the centromeres of the sister chromatids. Cytokinesis, on the other hand, is the process of physically dividing the cytoplasm of the cell into two daughter cells, which occurs after the sister chromatids have been separated during anaphase. Therefore, anaphase and cytokinesis are the correct answers for the phase of mitosis in which the sister chromatids are pulled apart.