October 31, 2013 Take out your Cell Division: Mitosis foldable. Turn in your Reinforcement. At your table, make two stacks: One for vocab One for PowerNotes Ms. Clark will come around and stamp them later in class.
Dec 29, 2015
October 31, 2013 Take out your Cell Division: Mitosis foldable.
Turn in your Reinforcement.
At your table, make two stacks: One for vocab One for PowerNotes
Ms. Clark will come around and stamp them later in class.
Model of the Cell Cycle You will work in pairs to model the cell cycle.
Instructions are on your table.
Read the instructions completely before starting the activity.
Leave some space below/around your drawings.
Cell Cycle Cell cycle can be broken down into three major parts:
Interphase (maintenance and growth) Mitosis (nuclear division) Cytokinesis (cytoplasmic division)
Cells divide at different rates. Some cells enter a G0 phase.
Cells in G0 carry on normal functions but are unlikely to divide.
Cells will not divide if they live in an environment which: Lacks essential nutrients, or Is too crowded/dense.
Interphase Cells spend about 90% of their life in interphase.
Purpose of interphase is to:
1. Have cells carry outtheir normal functions.
2. Prep cells for division.
Chromosomes in the nucleus exist in loose threads of DNA and protein called chromatin.
Interphase Gap 1 (G1):
Cell carries out its normal functions.
Cell grows and replicates its organelles.
Prophase Chromosomes condense at the start of mitosis,
during prophase. Chromatin condenses into thick rods called
chromatid.
Prophase Each chromosome in a cell
was replicated during interphase. The two identical chromatids
are called sister chromatids.
Sister chromatids are held together at the centromere.
Prophase At the same time, the nuclear envelope
begins to break down.
Centrioles, organelles that assist cell division, begin to migrate to opposite sides of the cell.
Spindle fibers grow from the centrioles and radiate to the center of the cell.
Metaphase Spindle fibers attach to each
pair of sister chromatids at their centromere.
The fibers help move the chromosomes to the middle of the cell.
Anaphase During anaphase, sister chromatids separate from
each other. Spindle fibers begin to shorten, pulling the identical
chromatids toward opposite sides of the cell.
Before Anaphase After Anaphase
Chromosome
Spindle fiber
Centromere
Telophase Once the complete set of identical
chromosomes reach opposite ends of the cell: A nuclear membrane begins to form
around each set of chromosomes. The chromosomes begin to uncoil out of
their tightly-packed form (chromatid) into their loosely-packed form (chromatin).
The spindle fibers fall apart.
Telophase Interphase is the growth and
maintenance stage of a cell.
Mitosis is the division of the cell nucleus and its contents. Stages of mitosis = PMAT
Telophase marks the end of mitosis.
Telophase
Cytokinesis Cytokinesis is the division of the cell’s
cytoplasm.
Cytokinesis marks the end of cell division.
Cytokinesis Each new cell is called a daughter cell
They are genetically identical to each other.
The daughter cells enter interphase and begin the cell cycle again.
Cytokinesis Cytokinesis differs in animal and plant cells.
In animal cells, the cell membrane forms a cleavage furrow. The daughter cells gradually move apart until
their membranes pinch close.
In plant cells, a cell plate grows between the two nuclei.
Model of the Cell Cycle Work with your partner to determine the
most important points of each phase in the cell cycle.
Write bullet points briefly describing this information.