Mitosis Review Biology Test Review Interphase where the
Mitosis Review Biology Test Review
Interphase � where the cell prepares itself for cell division � Interphase is not part of mitosis � Interphase is divided into three phases, G 1 (first gap), S (synthesis), and G 2 (second gap) � During all three phases, the cell grows by producing proteins and cytoplasmic organelles
Interphase- S Phase � the genome is composed of a number of chromosomes ◦ complexes of tightly-coiled DNA that contain genetic information vital for proper cell function � because each resultant daughter cell should be genetically identical to the parent cell, the parent cell must make a copy of each chromosome before mitosis � this occurs during the S phase of interphase
S Phase Duplication � Each new chromosome now contains two identical copies of itself, called sister chromatids � They are attached together in a specialized region of the chromosome known as the centromere �a chromosome always contains two sister chromatids
Mitotic/M Phase �Mitosis and cytokinesis together define the mitotic (M) phase of the cell cycle �the division of the mother cell into two daughter cells ◦ genetically identical to each other and to their parent cell ◦ This accounts for approximately 10% of the cell cycle
Mitosis- PMAT ◦ a eukaryotic cell separates the chromosomes in its cell nucleus into two identical sets in two nuclei ◦ generally followed immediately by cytokinesis ◦ The primary result of mitosis is the transferring of the parent cell's genome into two daughter cells ◦ Mitosis is important for the maintenance of the chromosomal set
Mitosis- Prophase (Early/Late) � Nonkinetochore microtubules have established a matrix around the degrading nucleus � The chromatin has condensed
Mitosis- Metaphase (Early/Late) � The nuclear membrane has just degraded, allowing the microtubules to quickly interact with the kinetochores (centromere) on the chromosomes ◦ the centrosomes have moved to the poles of the cell and have established the mitotic spindle ◦ the chromosomes, have all assembled at the metaphase plate � These microtubules can attach to kinetochores or they can interact with opposing microtubules � The chromosomes have aligned at the metaphase plate
Mitosis- Anaphase � Lengthening nonkinetochore microtubules push the two sets of chromosomes further apart � The kinetochore microtubules shorten � Which is true, pulling or pushing?
Mitosis- Telophase � The decondensing chromosomes are surrounded by nuclear membranes � Cytokinesis has already begun; the pinched area is known as the cleavage furrow
Mitosis Slides
Cytokinesis-C Phase � Divides: ◦ ◦ ◦ the nuclei Cytoplasm Organelles cell membrane into two cells containing roughly equal shares of these cellular components
Key Ideas � Centrosomes contain centrioles � Spindle fibers are nonkinetochores � Centromere is the kinetochore
Mitosis- Plant
C Phase of Plants � cytokinesis in plant cells is significantly different from that in animal cells due to the presence of a cell wall � plant cells construct a cell plate in the middle of the cell rather than forming a contractile ring (animal)
Stages of Cell Plate Formation (1) (2) (3) (4) (5) creation of the phragmoplast, an array of microtubules that guides and supports the formation of the cell plate trafficking of vesicles to the division plane and their fusion to generate a tubular-vesicular network continued fusion of membrane tubules and their transformation into membrane sheets upon the deposition of callose, followed by deposition of cellulose and other cell wall components recycling of excess membrane and other material from the cell plate fusion with the parental cell wall
Apoptosis ◦ is the process of programmed cell death (PCD) ◦ that may occur in multicellular organisms �differs from necrosis, in which the cellular debris can damage the organism
Cancer medical term: malignant neoplasm ◦ is a class of disease in which a group of cells display uncontrolled growth through division beyond normal limits ◦ invasion that intrudes upon and destroys adjacent tissues ◦ and sometimes metastasis, in which cancer cells spread to other locations in the body via lymph or blood
Causes of Cancer ◦ are primarily an environmental disease with 90 -95% of cases due environmental factors such as lifestyle ◦ 5 -10% directly due to heredity
Common Environmental Factors � cause or enhance abnormalities in the genetic material of cells ◦ ◦ tobacco (25 -30%), diet and obesity (30 -35%) infections (15 -20%) radiation, stress, lack of physical activity, and environmental pollutants
Test is Tomorrow � Good Luck!
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