The mitotic cell cycle Flashcards
Structure of a chromosome
Chromosomes are thread-like structures located inside the nucleus of animal and plant cells. Each chromosome is made of protein and a single molecule of deoxyribonucleic acid (DNA).
Importance of mitosis in the production of identical cells
It plays an important part in the development of embryos, and it is important for the growth and development of our bodies as well. Mitosis produces new cells, and replaces cells that are old, lost or damaged. In mitosis a cell divides to form two identical daughter cells.
Cell cycle processes
Interphase, prophase, metaphase, anaphase and telophase.
Prophase
Prophase is the first phase of mitosis, the process that separates the duplicated genetic material carried in the nucleus of a parent cell into two identical daughter cells. During prophase, the complex of DNA and proteins contained in the nucleus, known as chromatin, condenses.
Metaphase
During metaphase, the cell’s chromosomes align themselves in the middle of the cell through a type of cellular “tug of war.” The chromosomes, which have been replicated and remain joined at a central point called the centromere, are called sister chromatids.
Anaphase
During anaphase, each pair of chromosomes is separated into two identical, independent chromosomes. … The separated chromosomes are then pulled by the spindle to opposite poles of the cell.
Telophase
During telophase, the chromosomes begin to uncoil and form chromatin. This prepares the genetic material for directing the metabolic activities of the new cells. The spindle also breaks down, and new nuclear membranes form.
Cytokinesis
Cytokinesis is the physical process of cell division, which divides the cytoplasm of a parental cell into two daughter cells. It occurs concurrently with two types of nuclear division called mitosis and meiosis, which occur in animal cells.
Significance of telomeres in permitting continued replication
They protect chromosome ends from DNA degradation, recombination, and DNA end fusions, and they are important for nuclear architecture. Telomeres provide a mechanism for their replication by semiconservative DNA replication and length maintenance by telomerase.
Significance of stem cells in cell replacement and tissue repair
Given their unique regenerative abilities, stem cells offer new potentials for treating diseases such as diabetes, and heart disease. Research on stem cells continues to advance knowledge about how an organism develops from a single cell and how healthy cells replace damaged cells in adult organisms.
Chromosome behaviour during the mitotic cell cycle
So during a mitotic cell cycle, the DNA content per chromosome doubles during S phase (each chromosome starts as one chromatid, then becomes a pair of identical sister chromatids during S phase), but the chromosome number stays the same. A chromatid, then, is a single chromosomal DNA molecule.
Nuclear envelope behaviour during the mitotic cell cycle
At the beginning of mitosis, the chromosomes condense, the nucleolus disappears, and the nuclear envelope breaks down, resulting in the release of most of the contents of the nucleus into the cytoplasm. ..
Cell membrane during mitosis
The plasma membrane undergoes major shape changes during mitosis. During prophase, the nuclear pore complex disassembles and the nuclear envelope disengages from the nucleus and merges with the endoplasmic reticulum. This organelle is then partitioned and inherited by daughter cells.
Spindle in mitosis
Spindle fibers form a protein structure that divides the genetic material in a cell. The spindle is necessary to equally divide the chromosomes in a parental cell into two daughter cells during both types of nuclear division: mitosis and meiosis. During mitosis, the spindle fibers are called the mitotic spindle.
Interphase
The phase of the cell cycle in which a typical cell spends most of its life. The cell obtains nutrients and metabolizes them, grows, replicates its DNA in preparation for mitosis, and conducts other “normal” cell functions.
