Lab Exam Flashcards
Revolving Nose piece
Supports the various objective lenses and allows for simple changes of magnification
Stage
Supports specimen
Coarse Focus Knob, Fine focus knob
Allows rapid change and slow change of distance
Rough, final focusing
Ocular/Eyepiece
Usually 10x
Look through it to view the specimen
Parfocal
Condenser
Lenses that concentrate the light from the illuminator, no mag
Aperture iris diaphragm
Reduces glare from unwanted light by adjusting the angle of the cone of light
Resolving Power
Ability to see two distinct objects that are close together
Compound microscope:
Working distance decreases when magnification..
Increases.
Depth of Focus
Number of planes in focus
Increasing magnification decreases depth of focus
To calculate size of an object
screen size
or
scale bar
Real size= real FOV/on-screen FOV x on screen size of object
Real size= on screen length of object/on screen length of scale bar x real size of scale bar
Stereoscopic microscope
2 oculars (3D image)
Not inverted
Reflected (opaque) or transmitted light
Protoplast
Plant, bacterial, fungal cell with cell wall partially/completely removed
Plasmolysis
is the process in plant cells where the plasma membrane pulls away from the cell wall due to the loss of water through osmosis.
plant cell loses water and hence turgor pressure, making the plant cell flaccid (central vacuole shrinks too)
Chloroplasts
Photosynthetic
Spherical
Move due to cytoplasmic streaming or cyclosis
Deliver nutrients, metabolites and genetic info
Micrometer vs Nanometer
-6 and -9
Erythrocyte
Red blook cells, contain a large amount of pigment hemoglobin
Hemolysis
When volume of cell exceeds a critical volume, cell ruptures and pigment is released. Caused by diffusion of water by osmosis
Can also occur in an isotonic solution of penetrating soltution
Tonicity
Relative concentrations of solutes in the fluid inside and outside the cell
Hypotonic
Hypertonic
Isotonic
Hypo: increases volume (more concentrated within the cell(
Hyper: decreases volume
Isotonic: Equal osmotic pressures
Aquaporins
Membrane proteins that form canals in the membrane
Electrolyte:
dissociates into ions in solution
Glycerol
Thiourea
Urea
Dextrose
Sucrose
Triton 100-X
Ethanol
Water
G: polar, can penetrate easily
T: Sulfur (electronegative) low solubility, not easily
U: O atom can H bond with water
D: Smaller, fewer OH, readily diffuse
S: Larger, high OH, H bonding, slower diffusion rate
T: great size but increases permeability of the membrane
T: 1-OH large nonpolar easily dissolve in the membrane
Water: small molecules can easily diffuse
Factors affecting the rate of penetration of substance across cell membrane
Molecular size
Lipid solubility
Polarity
Ability to form H bonds with water
Hyaline Cap
Front hard portion of the ameoba
Plasmagel
Plasmasol
Gel: solid
Sol: liquid
Uroid End
Posterior end
Pinocytosis
Ingestion of liquid into the cell by the budding of small vesicles from the cell membrane
Endocytosis
The taking in of matter by a living cell nivagination of its membrane to form a vacuole
Phagocytosis
Ingestion of bacteria
Mitosis
M phase (mitosis and cytokinesi) and Interphase (g1, S, g2)
Interphase
Separate 2 cell divisions, period of growth and preparation
G1: growth, active synthesis of macromolecules
S: (sythesis) replication of DNA, synthesis of DNA associated proteins or microtubule associated proteins
At end, chromosomes consist of 2 chromatids
G2: protein sytnth and production of structures needed for mitosis (spindle fibres)
Kinetochore
Button like structure linking hte chromosome to mitotic spindle
Interphase
Growth, macromolecules, organelle assembly, DNA replication
Most cells in this stage at a given time
Prophase
Chromosomes shorten, thicken
2 chromatids at centromere
Microtubules disassemble
Nucleoli disappear
Centrosome duplicate
Prometaphase
Breakdown of nuclear membrane
Centrosomes are at opposite poles
On centromere of each chromatid, a kinetochore forms
Chromosomes migrate towards metaphase equatorial plate
Metaphase
Spindle tubules formed
Centromeres start to separate
Anaphase
Centromeres seaprate and each daughter chromatid moves to opposite poles
Cytokinesis begins
Telophase
Chromosomes decondense
Nuclear membrane reappears
Nuclei reform
Sprindle disappears
Cytokinesis occurs
Feulgen Stain
Colors DNA containing structures magenta red
First hydrolyzed with HCL to remove purine bases and form free aldehyde group on deoxyribose, to react with the stain
Apical meristems
Region of elongation
and root cap
Quinticentent centre
Growth centre found in root tips and stem tips
Just above cell division
Dead cells which protect from AM and pushes through soil
zone at the base of apical meristream, realive inactive region where cells remain in G1
Xylem cells
Phloem Cells
Transport water and salts from soil to rest of plants
Transport carbs from photosynthetic portion of plant to roots
Meiosis
Chromosome # remains stable
Genetic diversity
In plants: alteration
Diploid: sporophyte undergoes meiosis to for haploid spores (gemetophytes) which fuse to form zygote
Animals: alteration of ploidy levels
Diploid prodcues haploid (gametogenesis)
Male and female gametes fuse to form diploid zygote
Premeiotic Interphase
Similar to mitosis: but
20x longer
Sex chromosomes at beginning
Larger nucleus
Prophase I
Longest stage
Leptotene – initial condensation of chromosomes appear as single threads. Telomeres *tips of chromosomes* are attached to nuclear membrane
2) Zygotene – maternally and paternally derived copies of each homologous pair of chromosomes line up along their lengths (process = synapsis)
Chromatids of homologous chromosomes interwine and form a synaptonemal complex
3) Pachytene – adjacent chromatids break and join in a process called crossing over
Fully pairred homologues are called tetrads (4 chromatids)/ bivalents
4) Diplotene – chiasmata (region of crossing over) becomes visible
Synaptonemal complex disappears, and chrimosomes detach from nuclear membrane
5) Dikinesis
- Condensation of chromosomes finishes, final modifications occur, chromosomes are ready for division; nucleoli disappear
Metaphase I
Nuclear membrane breaks down
Paired homologues line up at the plate
Ordering of maternal and paternal homologues occurs at random
- Anaphase I
Centromeres do not split- homologues are pulled away from each other
Telophase I
Chromosomes decondense
Nuclear membrane reforms
Cytokinesis
Interkinesis
Like interphase in between M 1 and 2
No DNA replication or centriole duplication
Prophase II
Chromosomes recondense, nuclear envelope breaks down, spindle forms
Mataphase II
2 chromatid chromosomes line up
Anaphase II
Sister chromatids separate and move to opposite spindle poles, cytokinesis begins
Telophase II
- chromosomes decondense, nucleoli reform, nuclear membrane forms around each product, cytokinesis finishes
Results in 4 haploid and genetically different cells
Microspores
Megaspores
Process of creation
Male spores (anthers, pollen sac) Spermatogenesis
Female spores (oogenisis)
Sporogeneous cells become surrounded by layers of sterile cells innermost layers develop into cells that provide nutrition to the developic microscospore (tapetum) + outermost layer forms wall of microsporangium
sporogenous cells develop into microsporocytes, which divide by meiosis into microspores
Microspores divide mitotically to form a tube cell and a microgametophyte.
These cells and the spore wall form the pollen grain.
Ascaris fertilization shell: 3 layers
Outer membrane: the fertilization membrane with outer protein layer
The chitinous layer
The ascaroside layer and the perivitelline space
Spermatogonia
Largely stained outer cells, well defined nuclei
Divides by mitosis to produce more
Half of this population underoges meiosis to become sperm, the other half to replenish
Primary Spermatocyte
2n located just below spermatogonia, not as darkly stained
Large cells undergoing first meiotic division
Secondary spermatocyte
n
Product of first meiotic division, undergo second division to produce spermatids
Spermatids
n small circular cells that differentiate into functional spermatozoa
Spermatozoa
n
possess very long thin flagellum, located near the lumen
Nurse cells (Sertoli cells)
large nurse cells found in the walls of the seminiferous tubules which feed and regulate the differentiation of spermatids into mature spermatozoa
Primary follicles or Primordial, Unilaminar
Small, round structure at the periphery of the ovary
Each contains one oogonium (2n) surrounded by a layer of follicular cells
Cytokineiss of primary oocyte at the end of Meiosis I produces a large secondary oocyte and a polar body
Growing follicles
Larger follicles with a few layers of follicular cells
Graafian follicles
Very large follicles, most space is occupied by a large fluid filled cavity
Mature oocyte would be found at the centre of the follicle
Secondary/mature oocyte
When mature follicle ruptures at ovulation, the mature oocyte is released
Comes near to the epithelium prior to ovulation
Growing follicle (primary multilaminar)
Slightly deeper in the ovary, surrounded by several layers of follicular cells. Contains a primary oocyte
Oocyte
The cell that undergoes meiosis in the ovary.
Primary and secondary (mature with shell)
Perivitelline Space
Space between the membrane and the inside of the oocyte, this is where the polaar body resides after meiosis
Polar Body
During cytokinesis, the cells sometimes divide unevenly.
Most of the cytoplasm is in one daughter cell, the egg/ovum
The other smaller cells are called polar bodies. They frequently die but can be part of the lift cycle as well.
Ascaris
In telophase I the first polar body extrudes with 2 double chromosomes. In t2 the second polar body is expelled, 2 chromatids.. leaving 2 chromosomes
Tapetum
Layer of nutritive cells within the sporangium (anther)
Parenchymatous tissue
Soft cellular tissue in plants
Soft parts of leaves, pulp, bark, etc.
Chiasmata
In late prophase, might be visible.
Point at which paired chromosomes remain in contact during the first metaphase of meiosis, and at which crossing over and exchange of genetic material occurs between strands
Seminiferous tubules and
it’s lumen
Where sperm production occurs and the centre of the cell
Is the working distance greater or smaller if you were to switch from 40x to 10x?
T/F: the depth of field increase with the magnification factor?
False
(5 / 10) x 1 mm =
A - 2000µm
B - 5000µm
C - 500µm
D - 200µm
C
Is reflected or transmitted light preferable for observations of an opaque sample with the dissecting microscope?
Reflected
What type of solution causes plasmolyis?
Hypertonic, HIgh concentration of NaCl
How would CAT look under the stereomicroscope?
CAT
Which of these is granular? Ectoplasm, or endoplasm
Endoplasm
What’s 2mm +500 um + 0.1 cm in micrometers?
3500 um
What is happening during systole?
Contractile vacuole in amoeba releases the contents
What is happening during the S phase?
DNA synthesis
150 um + 1mm +0.3 cm (in um)
4150 um
In what region of the cell do chromosomes align themselves during metaphase?
Equatorial plate
What chemical group does the Feulgen stain react with?
Aldehydes
Mitotic spindle fibres are made of actin polymers?
NO. Tubulin microtubules
