PRELAB: MITOSIS INTERNET LESSON
http://teachers.olatheschools.com/apaepkeonw/
-INTRO TO ONION ROOT ACTIVITY
-READ THROUGH before STARTING ACTIVITY
-MITOSIS IN WHITE FISH & ONION ROOTS
-DETAILED SKETCHES! (take your time)
-use color when necessary [purple]
-CELLS ALIVE
-mitosis tutorial [play animation]
-cell cycle [basic animation / checkpoints]
-cell cam [cancer / bacteria ]
-cell quiz
-cell gallery
check out MEIOSIS
MITOSIS INTERNET LESSON
RED PEN OUT
PRELAB: MITOSIS INTERNET LESSON
ONION ROOT TIP CLASSIFICATION
20
10
3
2
1
56
28
8
6
2
PRELAB: MITOSIS INTERNET LESSON
MITOSIS IN WHITEFISH & ONION ROOT
a- Why is the whitefish used to study mitosis?
-CELLS RAPIDLY DIVIDE
b- What are the four stages of mitosis?
-PRO / META / ANA / TELO
c- How long does it take for mitosis to complete?
-SEVERAL HOURS
d- Why will most of the cells you view be in interphase?
-LONGEST STAGE
-grow/develop [metabolism]
-replicate DNA
-prepare
PRELAB: MITOSIS INTERNET LESSON
MITOSIS IN WHITEFISH
ANAPHASE
METAPHASE PROPHASE
TELOPHASE
PRELAB: MITOSIS INTERNET LESSON
MITOSIS IN ONION ROOT
ANAPHASE
METAPHASE PROPHASE
INTERPHASE TELOPHASE
LAB: OBSERVING MITOSIS/ONION ROOT
-DETAILED SKETCHES! (take your time)
-be NEAT: final copy
READ DIRECTIONS
WHEN LAB IS COMPLETED
-you may OBSERVE other slides
LAB: MITOSIS ONION ROOT
PROBLEM/QUESTION:
-Identify each stage of mitosis in a prepared slide of onion (allium) root
tips.
BACKGROUND:
-In a growing plant root, the cells at the tip of the root are constantly
dividing to allow the root to grow. Because each cell divides
independently of the others, a root tip contains cells at different stages
of the cell cycle. This makes a root tip an excellent tissue to study the
stages of cell division.
-Remember, interphase is not technically a part of Mitosis, but it is a part
of the cell cycle and many of the cells you will be observing are in
interphase.
LAB: MITOSIS ONION ROOT
LAB: MITOSIS ONION ROOT
PROCEDURE:
1-START with the microscope on LOW POWER OBJECTIVE / DIAPHRAM
open to widest setting.
2-OBTAIN a prepared slide of an onion tip root.
-Hold the slide up to the light to see the pointed ends of the root section.
-This is the root tip where the cells were actively dividing.
3-PLACE the slide on the microscope stage with the root tips pointing AWAY
from you.
-Using the LOW-power objective to find a root tip and focus it with the
COARSE adjust until clearly visible.
-Just above the root “cap” is a region that contains many new small cells.
-The larger cells of this region were in the process of dividing when the slide
was made.
-These are the cells you will be OBSERVING.
-Center the image, the SWITCH TO HIGH POWER.
LAB: MITOSIS ONION ROOT
4-OBSERVE the box-like cells that are arranged in rows.
-Select one cell whose chromosomes are clearly visible.
-If you need to change the focus when using the high power only use the
FINE ADJUSTMENT.
DATA:
5-SKETCH the cell that you selected in the circle below labeled A
6-SELECT (4) other cells whose internal appearances are DIFFERENT
from each other and from sketch-A.
7-Looking along the rows of cells you SKETCHED, IDENTIFY what
stage each cell is in. (see RESOURCE)
LAB: MITOSIS ONION ROOT
PRELAB: MITOSIS INTERNET LESSON
LAB: MITOSIS ONION ROOT
RESOURCE- Use the photos below as a guide to help IDENTIFY each
stage of your sketches.
CHROMATID
CHROMATIN
INTER PRO
META
ANA
TELO
PRELAB: MITOSIS INTERNET LESSON
LAB: MITOSIS ONION ROOT
8-Use the data table to RECORD the number of cell that you
OBSERVE in each of the stages.
LAB: MITOSIS ONION ROOT
CONCLUSION
1-What STAGE were the MAJORITY of the cells in?
-INTERPHASE
2-What EVIDENCE shows that mitosis is a CONTINUOUS PROCESS,
not a series of separate events?
-stages FLOW / BLEND into each other
LAB: MITOSIS ONION ROOT
3-SUMMARIZE what happens in each phase of MITOSIS: (use bullets)
PROPHASE Mitosis begins- chromosomes CONDENSE [chromatid]
 Centrioles appear
 Spindle fibers form
METAPHASE Chromatids attach to spindle fibers in MIDDLE
ANAPHASE Chromatids separate- AWAY
TELOPHASE 2 new nuclei form
 Mitosis ends
4-What is the end RESULT of mitosis AND why is it so IMPORTANT?
- (result) NEW CELLS [identical daughter cells]
- (important/function) REPAIR / REPLACE / GROW