8th Grade Science
Notes: The Purpose of Meiosis and Mitosis
1. What do you think the word “diploid” might mean?
What kind of feelings do you get from this word? Take a guess!
Let’s break the word apart.
Di=Two
Ploid=copies
We use the word diploid to describe a cell that has two almost identical chromosomes. With the
exception of sex cells, almost all of a human’s cells are diploid. We must have diploid cells to function.
In regards to a human we must have a pair of chromosomes to function. With that in mind, what is
something that is paired that you might use in your everyday life?
Example: The tongs of a tweezers. There are two of them and they must be almost identical in order to
function properly.
Now it’s your turn. Give me an example of something that is diploid. Be ready to share with the class
Example:
2. What do you think the word “haploid” means?
Let’s break the word apart.
Hapl=single
Ploid=copies
We use the word haploid to describe a cell that has only one chromosome. In its single, halved
form it becomes called a chromatid. Haploid cells with their chromatids are found in human sex
cells (sperm and egg cells). You started out as a combination of one haploid cell from your mom
and one haploid cell from your dad.
In regards to a human, a haploid cell must join with another haploid cell to make a human. With
that in mind, what is something that must be paired to make it functional?
Example: A single shoe. A shoe must be paired with another one to make the shoes functional.
Now it’s your turn. Give me an example of something that is haploid. Be ready to share it with
the class.
Example:
3. What does a diploid cell look like?
Write in your own words one thing you know about the word diploid.
A diploid cell with one chromosome will look like:
Draw out the chromosome and label it.
What would a diploid cell with 3 chromosomes look like?
Draw out the chromosomes and label them
4. What does a haploid cell look like?
Write in your own words one thing you know about the word haploid.
A haploid cell with one chromatid will look like:
Draw out the chromatid and label it.
What would a haploid cell with 3 chromatids look like?
Draw out the chromatids and label them
5. What do meiosis and mitosis look like?
Based on the following description, what does mitosis look like? Hint: fill in the chart. In this
case, consider the start cell to only have one chromosome.
Mitosis: starts with a diploid cell and ends with 2 diploid cells.
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Based on the following description, what does meiosis look like? Hint: fill in the chart. In this
case, consider the start cell to only have one chromosome.
Meiosis: begins with one diploid cell and ends with 4 haploid cells.
6.What are the purposes of meiosis and mitosis?
Keep that flow chart in mind as you watch the following video. Think about how the meiosis
and mitosis look relates to what their purpose is. Answer these questions.
a.What is the purpose of mitosis?
b.What is the purpose of meiosis?
In class assignment: Looking at the flow chart for meiosis and mitosis, how do the purposes of
each process relate to their end results. Write 4-5 sentences relating form to function for both
meiosis and mitosis.
*If you do not finish this in class, it will be done as homework and turned in tomorrow.