Biology
Name: ________________________________________________________________________ Class Period: _______
http://www.pbs.org/wgbh/nova/baby/divide.html
How Cells Divide: Mitosis
Step 1 – Before We Split
How Cells Divide: Meiosis
Step 1 – Before We Split
1. What is the end product of mitosis?
1. How many chromosomes are in the human genome?
2. How many chromosomes are in the human genome?
2. How many chromosomes are in a sperm or egg cell?
3. How many chromosomes are in a sperm or egg cell?
3. For each of the following diagrams, draw the
chromosomes of the mother in one color and the
chromosomes of the father in a different color.
Key: Chromosomes from father = [ ]
Chromosomes from mother = [ ]
Draw the cell as it appears during this stage.
Label the following parts:
- Nuclear envelope
- Nucleolus
- Chromatin
- Centrioles
Draw the cell as it appears during this stage.
Label the following parts:
- Nuclear envelope
- Nucleolus
- Chromatin
- Centrioles
Step 2 – Interphase
Step 2 – Interphase I
1. What replicates during this time?
1. What replicates during this time?
2. Why are chromosomes not visible during this stage?
Draw the cell as it appears during this stage.
Label the following parts:
- Nuclear envelope
- Nucleolus
- Chromatin
- Centrioles
Draw the cell as it appears during this stage.
Label the following parts:
- Nuclear envelope
- Nucleolus
- Chromatin
- Centrioles
Step 3 – Prophase
1. Each chromosome at this stage is made of two
identical copies. What are they named?
Step 3 – Prophase I
1. What occurs during this stage of meiosis that does not
occur during mitosis?
2. What forms the spindle?
3. What is happening to the nuclear membrane at this
stage?
Draw the cell as it appears during this stage.
Label the following parts:
- Nuclear envelope
- Spindle fibers
- Chromosomes
- Centrioles
Draw the cell as it appears during this stage.
Label the following parts:
- Nuclear envelope
- Spindle fibers
- Chromosomes
- Centrioles
Step 4 – Prometaphase (skip this stage)
Step 5 – Metaphase
Step 4 – Prometaphase I (skip this stage)
Step 5 – Metaphase I
1. Describe the movement of the chromosomes from
prophase to metaphase.
1. How is this stage different than metaphase of mitosis?
2. What is directing the movement of the
chromosomes?
Draw the cell as it appears during this stage.
Label the following parts:
- Chromosomes
- Spindle fibers
- Centrioles
- Metaphase plate
Draw the cell as it appears during this stage.
Label the following parts:
- Chromosomes
- Spindle fibers
- Centrioles
Step 6 – Anaphase
Step 6 - Anaphase I
1. Describe the movement of chromosomes during this
stage.
Draw the cell as it appears during this stage.
Label the following parts:
- Chromatids
- Spindle fibers
- Centrioles
1. How is this stage different than anaphase of mitosis?
Draw the cell as it appears during this stage.
Label the following parts:
- Chromosomes
- Spindle fibers
- Centrioles
Step 7 – Telophase
1. Why is mitosis considered complete after this stage,
even though the cell hasn’t fully divided?
Step 7 – Telophase I
1. How is this stage different than telophase of mitosis?
Draw the cell as it appears during this stage.
Label the following parts:
- Chromatids (now considered chromosomes)
- Nuclear envelope
- Centrioles
- Spindle Fibers
- Nucleolus
Draw the cell as it appears during this stage.
Label the following parts:
- Chromosomes
- Nuclear envelope
- Centrioles
- Spindle Fibers
Step 8 – Cytokinesis
Step 8 – Cytokinesis- End of Meiosis I
Draw the cell as it appears during this stage.
Label the following parts:
- Chromosomes
- Nucleolus
- Centrioles
- Nuclear envelope
Draw the cell as it appears during this stage.
Label the following parts:
- Chromosomes
- Nucleolus
- Centrioles
- Nuclear envelope
Step 9 – Interphase II
1. Does the DNA divide during this stage?
2. Are the new cells considered haploid or diploid at this
stage? Explain.
3. Is each chromosome made of one or two sister
chromatids at this stage?
Step 10 – Prophase II
1. Does crossing-over occur during this stage?
Draw the cell as it appears during this stage.
Label the following parts:
- Chromosomes
- Centrioles
- Nuclear envelope
Step 11 – Prometaphase II (Skip this stage)
Step 12 – Metaphase II
Draw the cell as it appears during this stage.
Label the following parts:
- Chromosomes
- Spindle fibers
- Centrioles
Step 13 – Anaphase II
Draw the cell as it appears during this stage.
Label the following parts:
- Spindle fibers
- Chromatids
- Centrioles
Step 14 – Telophase II
Draw the cell as it appears during this stage.
Label the following parts:
- Spindle fibers
- Nuclear envelope
- Chromatids
- Centrioles
Step 15 – Cytokinesis – End of Meiosis II
1. At the end of this stage, are the cells considered
haploid or diploid? Explain.
2. At this point, are the chromosomes made of one or two
sister chromatids?
3. What are the only types of cells that are produced with
this type of cell division?
4. Are the daughter cells genetically identical to the
parent cell? To each other?
Draw the cell as it appears during this stage.
Label the following parts:
- Chromatids
- Nuclear envelope
- Centrioles