TA Info. Francis (Frank) Iosue [email protected] Office = 192 Mendel Monday 9-10 AM Tuesday 9-10 AM By Appointment. Attendance. 260 points (37%) of your grade for the course will be based on lab Attendance is MANDATORY – NO Make-up labs
The Microscope & Plant Cells
Compound Light Microscope – useful for viewing slides
Dissecting Microscope – useful for viewing 3-D images.
ALWAYS HANDLE THESE EXPENSIVE PIECES OF LAB EQUIPMENT WITH EXTREME CARE!
Identifying the parts of a microscope
Know where parts are located & what each is used for.
TA will demonstrate proper use if you don’t remember! Always ask if unsure so that you do not damage the scope!
Drop of H2O onto slide
Very thin slice of potato onto drop
Use pipet to “mix up” specimen, then draw up
Place one drop of specimen onto slideHow to Make a Wet-Mount Preparation
TA will DEMONSTRATE Onion wet-mount….
…“I can’t see anything on my slide!”
-first time scope user
3. Now, while looking through the eyepiece, use coarse focus knob to “focus downward” on your specimen.
[Focusing “upward”, that is moving the stage upward toward the objective lens, may result in breaking your slide & damaging the objective lens – never do this].
ALWAYS, ALWAYS, ALWAYS – FOCUS DOWNWARD!
CELLS are the basic unit of life. All plants are comprised of cells.
Prokaryotes vs. Eukaryotes
Prokaryotes: cells which do NOT contain a membrane-bound nucleus or other organelles. Instead, prokaryotes have a plasma membrane only.
Examples: bacteria & cyanobacteria.
Largest prokaryotes = CYANOBACTERIA
[a.k.a. “blue-green algae”]
Prepare wet-mounts of & examine (sketch):
For answer: Compare your observations of cyanobacteria to DEMOs of bacterial cells.
Structure of Plant Cells
cuboidal shape & numerous organelles
Types by Function:
SclerenchymaExamples of: Support Cells & Tissues
A = Phloem(green cells)
B= Xylem(red cells)
Longitudinal sections: note patterns of lignified cell walls
Longitudinal section: showing sieve tube members with “sieve-like” end wall & associated companion cells.
Cross section: showing green phloem cells in a vascular bundle w/ xylem.
Cross section: showing cellular inclusions. What are these inclusions & what do they tell you about the function of this type of parenchyma???
Plant stem – parenchyma cells make up the cortex
-prevents H2O loss
-regulate CO2 in & O2 out of plant cells
Outermost layer of cells = epidermis
Guard cells surrounding stomata opening (within epidermal layer)
Trichomes = extensions of epidermis
Found in roots & stems.
Lab Manual pp. 1-20
Label parts of microscope & recall proper usage (proper focusing technique, field of view, depth of view, magnification).
Making wet-mounts of potato, onion…for practice.
Study wet-mounts of cyanobacteria in part 2.
Part II – Specialized Plant Cells & Tissues
Lab Manual pp. 21-42
Cyanobacteia wet-mounts & sketches (label diagrams!)
Bacteria types DEMO slide
Plant cell general structure
Specialized Cells & Tissues
Support, Vascular, Storage & Protective types
View various slides of each, sketch, & label.TODAY’S PLAN:Summary