Lab 9 REVAMP

Why is mitotic cell division important?

• Asexual reproduction

• Growth (increase in cell number)

• Cell replacement

What are the three main intervals of the cell cycle? Why is each important?

• Interphase (G1, S, G2) – growth and preparation for division

• Mitosis – division of the nucleus

• Cytokinesis – division of the cytoplasm

List the three subphases of interphase. What occurs during each?

• G1: cell growth and normal functions

• S: DNA replication

• G2: preparation for mitosis

Contrast mitosis vs. cytokinesis.

• Mitosis: nuclear division

• Cytokinesis: cytoplasmic division

Contrast chromatin vs. chromosome.

• Chromatin: long, thread-like DNA

• Chromosome: condensed, rod-like form of DNA

Label the parts of a replicated chromosome.

• Sister chromatids

• Centromere

• Kinetochores (where spindle fibers attach)

What structures are evident when a cell is in interphase?

• Nuclear envelope

• Nucleolus

• Chromatin

Know the mitotic phases in order and the events.

• Prophase: chromosomes condense, nuclear envelope and nucleolus disappear, spindle fibers form

• Metaphase: chromosomes line up in the middle

• Anaphase: sister chromatids separate

• Telophase: chromosomes relax into chromatin, nuclear envelope and nucleolus reappear, spindle fibers break down

Be able to recognize structures associated with each phase.

Know:

• Chromosomes

• Chromatin

• Nuclear envelope

• Nucleolus

• Spindle fibers

• Centrioles (animal cells)

• Cell plate (plant cells)

• Cleavage furrow (animal cells)

When does DNA replication occur?

S phase of interphase.

What structures indicate that a cell has entered cytokinesis?

• Cell plate in plants

• Cleavage furrow in animals

Contrast animal vs. plant cytokinesis.

• Animal: cleavage furrow forms

• Plant: cell plate forms

Which term refers to DNA during interphase?

Chromatin

Which term refers to DNA during mitosis?

Chromosome

If a cell with 500 chromosomes undergoes mitosis and cytokinesis, what is the result?

• 2 daughter cells

• 500 chromosomes in each daughter cell