meiosis, mitosis notes - JGMS

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Date ____________
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Notes – Cell Division (Mitosis and Meiosis)
Cell division is crucial to the creation of new cells for the body AND the passing of genetic
material from parents to offspring. Cell division creates new cells to meet the needs of the
body: growth, development, repair, and reproduction.
1. Cell Division (pages 76C – 78C)
a. How are you like most organisms including ants and oak trees?
b. What are the three functions that require cell division in multicellular organisms?
i.
ii.
iii.
c. What is meant by multicellular organism?
d. How does a multicellular organism grow through cell division?
e. Continue the pattern, how many cells will result after 3 more cell divisions?
Original Cell
1st Cell Division =
Two New Cells
2. Mitosis (p. 81C – 83C)
a. Define mitosis.
b. When a cell divides in mitosis, each new cell gets a _____ set of DNA.
c. As a result of mitosis, the original or parent cell splits into two _____ cells.
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Date ____________
Page ___
Model Mitosis – We are going to model an organism with 4 chromosomes but the process is the
same for humans with 23 chromosomes.
a. Using four colors, draw
four duplicated chromosomes
inside of a nucleus.
Step 1
Chromosomes
Condense
b. Using the same four
colors, draw the four
chromosomes lined up
vertically; the nucleus has
disappeared.
Step 2
Chromosomes
Line Up
c. Using the same four
colors, separate the upper
chromatids and lower
chromatids to opposite sides
of the cell.
Step 3
Chromosomes
Separate
d. Using the same four
colors, draw the chromatids
inside a nucleus within each
cell.
Step 4
Nuclei Form (Cells
Pinch and Divide)
Meiosis (p. 117C – 122C)
a. What do you think would happen if two body cells with 46 chromosomes each were
combined to create an offspring?
b. Define gamete.
c. Gametes are only found in the __________ organs of animals. The gametes produced in
the reproductive organs of males are __________. The gametes produced in the
reproductive organs of females are __________.
d. __________ is the process that takes place when __________ and __________
combine to create one new cell (offspring).
e.
egg cell, gamete,
( __ chromosomes)
fertilized egg cell
( __ chromosomes)
sperm, gamete,
( __ chromosomes)
f. Define meiosis.
g. As a result of meiosis, __________ new cells are created with half of the chromosomes
of the original cell.
h. Meiosis only occurs in the __________ organs of the body.
Model Meiosis - We are going to model an organism with 4 chromosomes but the process is the same
for humans with 23 chromosomes.
a. Using two colors, draw
four unduplicated
chromosomes in two
different sizes.
Parent Cell
Chromosomes Condense
and Nucleus Disappears
b. Using two colors, draw
the four chromosomes
replicated.
Part of Division 1:
Chromosomes Replicaate
c Draw one chromosome
from each pair on
separate sides of the cell.
Part of Division 1:
Like Chromosomes Pair Up
d. Draw the chromosomes
with pieces interchanged.
Part of Division 1:
Chromosomes Swap
Portions of their DNA
e. Draw one of each pair in
the daughter cells.
f. Draw half of each
chromosome in each
daughter cell.
Part of Division 1:
Chromosomes Pairs Divide
Part of Division 2:
Daughter Chromosomes
Divide Again
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