Cell Cycle and Mitosis RHSA

Cell Cycle The life cycle of all cells has two main parts: 1. Interphase 2. Mitosis and cytokinesis

Interphase A cell spends most of its lifetime in interphase growing and replicating chromosomes. Interphase is divided into: 1. G1 phase 2. S phase 3. G2 phase

Interphase: G1 phase During the G1, or growth 1 phase of interphase, the cell makes new molecules and grows larger. This phase can be long or short depending on the type of cell and the health of an organism.

Interphase: S phase S is for synthesis of more DNA. During the S phase the uncoiled chromosomes, called chromatin, are replicated or duplicated. During interphase, the nucleus looks like a dark blob (individual chromosomes are not visible).

Sister Chromatids During replication single stranded chromosomes become double stranded chromosomes. The 2 strands are identical to each other and are called sister chromatids. A centromere holds chromatids together.

Find onion cells in interphase!

Interphase: G2 phase During the G2 or growth 2 phase the cell again synthesizes more molecules and grows larger.

Mitosis Only a very short part of a cell’s life is spent in mitosis. During mitosis all of the cell’s chromosomes are evenly divided and they move to opposite ends of the cell Mitosis has 4 steps: prophase, metaphase, anaphase and telophase

Find cells undergoing prophase, metaphase, anaphase and telophase.

Cytokinesis After mitosis, the cell divides all the cytoplasm and organelles in the process of cytokinesis.

Online resources Mitosis animation Mitosis videos mitosis.html mitosis.html Mitosis quizzes sis1.html sis1.html tosisisg/quiz.htmlhttp:// tosisisg/quiz.html sis_review.htmhttp://local.brookings.k12.sd.us/biology/ch10celldivision/mito sis_review.htm

More websites Cell Cycle Game dex.html dex.html Cell Division Powerpoint