Activity 4: Cell Cycle Activity 4: Cell Cycle and Mitosisand Mitosis

Postlab DiscussionPostlab Discussion

WHITEFISH BLASTULAWHITEFISH BLASTULAWHITEFISH BLASTULAWHITEFISH BLASTULA

INTERPHASEINTERPHASEINTERPHASEINTERPHASE

PROPHASEPROPHASEPROPHASEPROPHASE

METAPHASEMETAPHASEMETAPHASEMETAPHASE

ANAPHASEANAPHASEANAPHASEANAPHASE

EARLY TELOPHASEEARLY TELOPHASEEARLY TELOPHASEEARLY TELOPHASE

LATE TELOPHASE AND LATE TELOPHASE AND CYTOKINESISCYTOKINESISLATE TELOPHASE AND LATE TELOPHASE AND CYTOKINESISCYTOKINESIS

Also watch:Also watch:

http://www.youtube.com/watch?http://www.youtube.com/watch?v=VlN7K1-9QB0v=VlN7K1-9QB0

Answers to Guide Answers to Guide Question:Question:

1. Why is the fish embryo used to 1. Why is the fish embryo used to demonstrate the different stages of demonstrate the different stages of the cell cycle?the cell cycle?

Cells are actively undergoing cell Cells are actively undergoing cell divisiondivision

Cell division occurs Cell division occurs asynchronouslyasynchronously

2. As you scan through the different 2. As you scan through the different cells for the whitefish blastula, which cells for the whitefish blastula, which of the stages of cell cycle is frequently of the stages of cell cycle is frequently observed? Why is this so?observed? Why is this so?

InterphaseInterphase A cell spends most of its time in A cell spends most of its time in

interphaseinterphase– Stage of growth, respiration, protein Stage of growth, respiration, protein

synthesis, etc. synthesis, etc.

3. Differentiate the following 3. Differentiate the following terms: chromatin, chromosome, terms: chromatin, chromosome, chromatids:chromatids:

CHROMATINCHROMATIN - single, thin DNA strands - single, thin DNA strands + histones and other proteins+ histones and other proteins

CHROMOSOMECHROMOSOME - single large - single large macromolecule of macromolecule of condensedcondensed DNA, and DNA, and constitutes a physically organized form of constitutes a physically organized form of DNA in a cell DNA in a cell

CHROMATIDCHROMATID - one of two identical - one of two identical strands of DNA making up a chromosome strands of DNA making up a chromosome that are joined at their centromeres that are joined at their centromeres

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Thank you.Thank you.