Lab Practical 1 Flashcards
Identify the Image
Top, right side, left side

- Ocular
- Stage
- Focus
- Objective
- Condenser diaphragm
- Field diaphragm
Identify the Image
Left, Right

- Manufacturer
- Magnification
- Tube length
- Magnification Color Code
- Lens Correction
- Numerical Aperature
- Indicates Oil Objective
- Coverglass Thickness
Identify the Type of Light Microscopy

- Bright field microscopy
- Darkfield microscopy
- Phase-contrast microscopy
- Transmission electron microscopy (TEM)
Identify the Type of Light Microscopy

- Nomarski (differential interference contrast)
- Fluorescence microscopy
- Confocal laser scanning microscopy
- Scanning Electron microscopy (SEM)
What is the purpose of the objective? What is the range in magnification?
Provides the main source of magnification
Range in magnifications of 2.5-100x
What is the purpose of an eyepiece?
Used to view the specimen image magnified by the objective
What is the purpose of a stage?
Holds the specimen and allows for movement within the optical path of the micrscope
What is the purpose of focus knobs (fine and coarse)?
Raise and lower the height of the objective, thereby changing the plane of focus
What is the purpose of the condenser?
Focuses the light passing form the lamp to the specimen
Its height relative to the specimen is essential in establishing Köhler Illumination
What is the purpose of the condenser knob?
Raises and lowers the condenser
What is the purpose of a condenser diaphragm?
Regulates the amount of light passing through the condenser
Adjusting its diameter regulates how much light illuminates the specimens - closing condenser diaphragm can reduce scattered light traveling through the microscope, thus improving resolution
What is the purpose of the field diaphragm?
Located above the lamp housing/light source
It regulates the amount of light traveling form the lamp to the condenser
What is the light source?
Consist of a bulb which provides illumination
What is Köhler illumination?
A lighting technique so the specimen can be uniformly lit with minimal interference from the internal components of the microscope
What are the two focal planes established in Köhler illumination?
- The Conjugate Field Planes; back of the retina, field stop of injective, the specimen, and the field diaphragm are all in focus at once
- The Conjugate Aperature Plane; iris of the eye, rear focal plane of the objective, the front focal plane of the condenser, and the lamp filaments are all in focus at once
Light Microscopy
Light microscopy utilized light to illuminate the speciment
Bright-field microscopy
The specimen is illuminated with the full wavelengths of visible light and contrast in the image is provided by the specimen itself
Both live and preserved specimens can be viewed
How do you improve contrast with bright field microscopy?
If the specimens are preserved you can use a Hematoxylin and Eosin (H&E) stain
Dark Field Microscopy
The exclusion of unscattered light, thus regions that don’t scatter light (no specimen) appear black
If you need increased contrast of a live specimen, what microscopy technique should you use?
Dark Field Microscopy
Phase Contrast Microscopy
Utilizes the differences in refractive indices within a specimen to improve contrast
What microscopy is especially useful for viewing unstained specimens and viewing edges of structures where refractive index becomes more evident?
Phase Contrast
Differential Interference Contrast (DIC)
Aka Nomarski
Similar to Phase Contrast microscopy
It utilizes polarized light to create two separate coherent image components which are then recombined
The interference generated during the recombination allows for difference in refractive index to be detected, thereby creating increased contrast
What microscopy technique is especially useful for viewing intracellular components such as vesicles
Differential Interference Contrast (DIC)
aka Nomarski
What are the two types of fluorescence microscopy?
- Epifluorescence Microscopy
- Confocal Microscopy
What are the three types of microscopy discussed in class?
- Light Microscopy
- Fluorescence Microscopy
- Electron Microscopy
What are the 4 types of light microscopy?
- Bright field
- Dark field
- Phase contrast
- Differential Interference contrast (DIC)
What are the two types of electron microscopy?
- Scanning Electron Microscopy (SEM)
- Transmission Electron Microscopy (TEM)
Fluorescence Microscopy
Fluorescent dyes (fluorochromes) are able to absorb wavelength at a particular light and re-emit light at a slightly longer wavelength of light
These dyes are then typically linked to antibodies or other compounds which bind to specific cellular structures
Epifluorescence Microscopy
A specimen is stained with a fluorescent dye and then illuminated with a fluorescent light source of a particular wavelength
Regions of the cell with the bound dye will emit light at a specific, slightly longer wavelength
What are some examples of frequently used dyes for epifluorescence microscopy?
- DAPI (illuminated by UV light and emits a blue light)
- FITC or GFP (excited by blue light and emits green light)
- Rhodamine/Red (excited by green light and emits a red light)
What is the pro and con of fluorescent microscopy?
- Pro = allows for visualization of specific subcellular components
- Con = Reliant on specific fluorescent dyes
Confocal Microscopy
utilizes lasers to illuminate the fluorescent dye
only collected data from a specific defined focal plane
Provides a more detailed fluorescent image
Electron Microscopy
Bombards the specimen with electrons
What is the biggest advantage of electron microscopy?
Allows for greater magnification and visualizing much smaller objects
In order to generate contrast in electron microscopy what needs to happen?
The specimens must be coated or stained with material with will prevent the passage of electrons
Scanning Electron Microscopy enables one to visualize what?
The outer surface of the speicimen
How does Scanning Electron Microscopy work?
The specimen is preserved and coated in a fine layer of gold
When electrons are projected at the specimen, they reflect off the gold and are detected by sensors which generates the image
Since the specimen is gold-coated only external details are evident
Transmission Electron Microscopy (TEM) enables one to view what?
Internal Structures
How does Transmission Electron Microscopy (TEM) work?
The specimen must be embedded in a hard resin and then cut into then secions
The sections are stained with electron-opaque stains which differentially bind to various intracellular components
Electrons are projected onto the specimens and will either pass through the specimens or are blocked
Detectors collect the transmitted electron to generate an image
Preparation of specimens for _____ requires significantly more work and skill relative to ____ (electron microscopy)
TEM
SEM
Label the Stages Of Cell Divison

M-phase Mitosis
G1
S Phase (DNA synthesis)
G2
Identify the Image

Diakinesis
Identify the Image
Top, Left, Right

Pachytene
Diakinesis
Late Diplotene
Identify the Image

X chromosomes
Leptotene
Identify the Image

Leptotone
Zygotene
Packytne
Diplotene
Diakinesis
Identify the Image
Top from left to right

Leptotene
Zygotene
Pachytene
Diplotene
Diakinesis
Identify the Image

Prophase I, Metaphase I, Anaphase I, Telophase I
Prophase II, Metaphase II, Anaphase II, Telophase II
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Metaphase
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Interphase
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Prophase
Centrioles
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Prometaphase
Microtubules
Nuclear Membrane Breakdown
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Metaphase
Metaphase Plate
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Anaphase
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Telophase
Cleavage Furrow
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Pachytene
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Prometaphase
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Prophase
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Telophase
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x-chromosomes
Zygotene
G1 Phase/ Gap 1
What is it? What is produced (4)? Length? Metabolically Active?
period of preparation for division
production of:
- Nucleotides
- Amino acids
- Enzyme systems
- Reserve Engergies
Long Phase
Metabolically Active
G2 Phase / Gap II Phase
What is it? What is being produced? Length?
Production of molecules necessary for mitotic development
- Spindle fiber protiens
- Microtubules
Fairly short
M Phase
what is it?
Separation of chromosomes followed by cell divison
Karyokinesis
Separation of chromosomes
The first stage of mitosis or meiosis
Cytokinesis
separation of the cell cytoplasm
resulting cells may be equal or unequal in size
Which phases comprise interphase?
G1-G2
During G1-G2 phases, can you see chromosomes?
No
G0
A special resting phase that terminally differentiated cells enter
Divisions are halted
Prophase (4 primary events)
Chromosomes condense,
nucleolus,
disappears,
centrioles replicate
Prometaphase (3 major events)
Nuclear envelop fragments
Microtubules bind to kinetochores
Non-kinetochore microtubules overlap
Metaphase (1 major event)
Mitotic spindle organizes and directs chromosomes to equatorial plate
Anaphase (2 events)
Chromatids separate
Chromatids are pulled to opposite ends of cell
Telophase (4 events)
Nuclear envelope reforms
Chromosomes uncoil and become indistinct
Nucleoli reappear
Cytoplasm divides
What happens during S period?
Chromosomes replicate again and prepare for the next division
The two daughter cells are mitosis are diploid or haploid?
Diploid
What are the stages of mitosis?
- Prophase
- Prometaphase
- Metaphase
- Anaphase
- Telophase
What are the stages of Meiosis?
Prophase I
Metaphase I
Anaphase I
Telophase I
Prophase II
Metaphase II
Anaphase II
Telophase II
Names have been assigned to distinguish the changing chromosomal states during prophase I stage. What are they?
- Leptotene
- Zygotene
- Packytene
- Diplotene
- Diakinesis
Leptotene - distinguishing features
Chromosomes have replicated forming sister chromatids
Cell in enlarged
The X chromosome is condensed and seen as a dark oval on one side of the chromosomal mass
Zygotene (synaptene)
Begins as sister chromatids start forming synapses with their homologous pair (tetrad)
Tetrad
Homologous pair of sister chromatids
Pachytene
starts at the conclusion of synapses formation
Some crossing over may happen at this stage
When does crossing over occur?
In the Pachytene and Diplotene stages of Prophase I
Diplotene
Homologous pairs start to separate (de-synapses) but remain attached at chiasmata
RNA synthesis is occurring
Chiasmata
Regions where crossing over has occurred
Eggs of many species arrest at what stage?
The diplotene stage of prophase I
Diplotene arrest
Lampbrush Chromosomes
occurs in the diplotene stages of some mammals (not humans though)
Diakinesis (3 main events)
The nucleus is now prepared for what?
“moving apart”
Contraction and repulsion continue
Chromosomes detach form nuclear envelope
RNA synthesis stops
The nucleus is now prepared for the two critical maturation divisions
Why do the chromosomes look so weird (rings, crosses, bars, coils) during diakinesis?
Terminalization of chiasmata on the bivalent pairs continues during diakineses
Metaphase I meiosis
terminalized bivalents (doubled homologous chromosomes) line up at the equatorial plate
DIFFERENT from MITOSIS (homologous chromosomes)
Anaphase I of Meiosis (3 events and end result)
homologous chromosomes migrate to respective poles
Centrosomes have never divided
Any chiasmata become free
Each end of the cell now has a haploid set of chromosomes (two chromatids)
Telophase I
symbolically ends the first phase of meiosis
THIS IS A REDUCTIONAL DIVISION
If cells form at telophase I what genetic makeup would they have?
They would be genetically haploid
Does telophase happen in all cell types?
No
What must happen to have a Prophase II?
What does Prophase II mark?
Prophase II is only present if a telophase I and pseudo interphase are present
This is the beginning of the equational division
Metaphase II
Centromeres line up on equatorial plate
(same as metaphase of mitosis?)
Anaphase II
Centromeres divide
The division splits the replicated chromosomes
Telophase II
either one or both cytoplasmic divisions will occur at this time
The second meiotic division is _______
AN EQUATIONAL DIVISION
Identify the Image

Primary spermatocytes
Secondary Spermatocytes
Spermatids
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Cyst
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Spermatogonia
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Primary Spermatogonia
Secondary Spermatogonia
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Spermatid
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Mature Sperm
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Across the top left to right
Across bottom left to right

Primary spermatocytes
cyst
spermatids
spermatozoa
spermatogonia
secondary spermatocytes
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top to bottom

Vas deferens
Epididymis
Testis
Seminiferous tubule
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Cross Section of Seminferous tubule
Identify the Image
across the top (left to right), down the side, across the bottom (right to left)

Sertoli cell
Type B spermatogonium
Type A2 spermatogonium
Type A1 spermatogonium
Primary speratocyte
Secondary spermatocyte
Spermatids
Sperm
Residual Body
Identify the Image
Top, down the left side, up the right side, center

Stratum granulosa
Theca interna
Corona radiata
Theca externa
Primary ooctye
culumus oophorous
antrum filled with liquor folliculi
Identify the Image
Left, bottom, right

Acrosome
Nucleus
Flagella
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left top to bottom, right side top to bottom

Egg nests
Germinal epithelium
oocyte
granulosa cells
intermediate follicle
primary follicle
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Primary Follicle
primary oocyte
granulosa cells
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Theca cells
Granulosa cells
Primary ooctye
intermediate follicle
Identify the Image
down the right side, top center, center, left, bottom corner

Theca interna
zona pellucida
theca externa
antrum
primary oocyte
granulosa cells
Graffian follicle
Identify the Image
left, right

seminiferous tubule
Leydig cells
Identify the Image
down the left side, down the right side

Spermatid
Spermatozoa
secondary spermatocyte
spermatogonia
primary spermatocyte
Identify the Image
down the left, down the right

Spermatid
spermatozoa
sertoli cell
primary speratocyte
secondary spermatocyte
spermatogoina
Identify the Image
Down the left side, right

primary follicle
stratum granulosa
intermediate follicle
antrum with liquor folliculi
zona pellucida
theca follicula
corona radiata
cumulus oophorous
egg nests
Identify the Image
top, then counterclockwise

Sertoli cells
primary speratocyte
spermatozoa
spermatid
interstitial cell
spermatogonia
Cyst
a cohort of presumptive germ cells in exactly the same stage of development
Testicular lobe
Testes are comprised of multiple lobes
Development occurs form the apical to the basal region
The term primary spermatocytes applies to all presumptive gametes in the testis which have grown to be ____ and have _____ staining nuclei than the spermatogonia
Larger
Darker
Nebenkern
Definition and what it is found in
A dark condensation in the cytoplasm containing the mitochondria
Found in spermatids
A short filamentous tail will be seen protruding from the spermatid even in the earliest stages of ________
This filament represents the ____ filament of the tail of the future _______
Spermiogenesis
Axial filament
Spermatozoan
The chromosomes cannot be identified in the nucleus by any staining procedure of the ___________ because they are so densely packed
Spermatozoan
Sertoli Cells
Recognized by large, dark nuclei and clear cytoplasm
Provide physical support, mediate movement of steroids, restricts movement of macromolecules, phagocytose degenerating spermatogenic cells
Interstitial Cell of Leydig
Location and funciton
Located between seminiferous tubules
Produce testosterone
Stroma
general location
what is it
Bulk of the ovary = stroma
connective and interstitial tissue with blood vessels
Egg Nests
Clusters of oogonia
Located just inside the germinal epithelium (no granulosa cells yet)
Theca differentiate into what two layers?
Theca Interna
Theca Externa
Antrum
Fluid-filled spaces which unite to form a cavity
Graafian Follicle
Mature follicle
Antrum filled with liquor folliculi
Nearly ready to rupture and release egg
Zona pellucida
What is it?
What does it consist of?
Non-cellular, secreted layer surrounding the primary oocyte within the graffian follicle
Consists of mucopolysaccharide and typsin-digestible material
Corona Radiata
The stalk the oocyte rests upon
Cumulus oophorus
made up of follicle cells within the antrum
Corpus luteum
What is it?
Function?
Follicle cells and theca cells that remain in the ovary after ovulation
Primarily produces the hormone progesterone
Mammalian oocytes have relatively small amounts of yolk that are uniformly distributed, while avian oocytes have an abundant store of yolk causing the nucleus to be displaced peripherally
True
What does corpus letuem mean in latin?
Yellow Body
corpus albicans
What is it?
Latin for what?
Inactive fibrous tissue that forms after involution of the corpus luteum
white body (cells lyse = empty looking vesicle)
Atretic follicles
Degenerating follicles
degeneration may occur at any stang
Identify the Image
Top, under top, left, right

Male pronucleus
chorion
first polar body
dyad
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Top left, counterclockwise

Fertilization envelope
chorion
perivitelline space
male pronucleus
2nd polar body
1st polar body
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Ascaris
sperm
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Ascaris fertilization
sperm penetration
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right, left, bottom

Male pronucleus
tetrad
chorion
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A. Sperm is bond to the surface of the egg
B. Sperm has entered into the egg as the fertilization cone forms while the tail still remains outside of the egg
C. The sperm has entered the egg cytoplasm and the fertilization cone has closed around the sperm
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Germinal Vesicle
Immature oocyte
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Mature egg
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Development of the acrosomal filament
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Fertilization envelope
Female pronucleus
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Top to bottom

Flagellum
acrosome
nucleus
mitochondria
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Bound sperm x2
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TEM
Bound sperm
arrow points to acrosomal filament contacting egg surface
Microvilli (back arrow) are found on the egg surface
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DIC
unfertilized zebra mussel egg
uniform in appearance, little yolk, clear cytoplasm
Identify the Image

Fluorescent Microscopy
Unfertilized zebra mussel egg
DNA-specific blue dye
Egg is arrested in metaphase I
Identify the Image

Phase micrograph
sperm inside the egg cytoplasm
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Fluorescent micrograph
actin-specific dye
Fertilization cone at site of sperm entry
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Phase contrast micrograph
Fertilized zebra mussel egg
1st polar body
Identify the Image

Fluorescent Micrograph
Fertilized Zebra Mussel Egg
1st polar body
female DNA
sperm DNA
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Phase contrast micrograph
Fertilized zebra mussel egg
1st polar body
2nd polar body
Identify the image

Fluorescent micrograph
fertilized zebra mussel egg
1st polar body
2nd polar body (doesn’t shine as bright because it has half the DNA as the 1st)
Identify the Image
Left to right

Series showing the migration of
the male pronucleus
toward the female pronucleus
Polar bodies
Identify the Image

Acrosome
Nucleus
Mitochondria
Flagellum
Acrosomal Filament
7 steps of fertilization
- Activation of Sperm (capacitation)
- Penetration of sperm through jelly or cumulus layer
- Fusion of sperm and egg
- Establishment of blocks against entry of additional sperm
- Completion of meiosis
- Entry of sperm into egg cytoplasm
- Metabolic activation of egg
Fertilization cone
A collection of microfilaments that form at the spot of sperm entry result in a protrusion on the egg surface
Fertilization envelope
Prior to fertilizaation = thin extracellular coat = vitelline envelop
Following fertilization = realease of cortical granuals = vitelline envelop is elevated from egg = fertilization envelope
Pronuclear membrane
Once sperm enter into the cytoplasm, the sperm DNA decondensed and a new membrane forms around the DNA
Chorion
The thicker fertilization envelope
Space is filled with a fluid (probably derived from the oocyte)
Dyad
one of a pair of chromosomes resulting from the separation of two homologous members of a tetrad
Identify the Image
Center title, left top to bottom, right image top to bottom

Neurulation
Neural fold
Neural groove
Neural ridge
archenteron
coelom
Early neurola
Neural tube
archenteron
late neurula
Identify the Image
Top, couterclockwise

Animal pole
frog 2-cell stage
vegetal pole
blastomeres
1st cleavage plane
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Micromeres
Macromeres
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Left most, clockwise

Animal pole
Vegetal pole
Late blastula
Macromeres
Micromeres
Blastocoel
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top to bottom

Animal pole
micromeres
blastocoel
marcromeres
vegetal pole
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Top left, counterclockwise

~Early Frog Gastrula~
animal hemisphere
vegetal hemisphere
dorsal lip of the blastopore
macromeres
micromeres
blastocoel
Identify the Image
Top to bottom

~Early Frog Grastula~
Animal pole
blastocoel
micromere
dorsal blastoporal lip
macromere
vegetal pole
Identify the Image
Left, top, right

Follicle cells
Supernumerary nucleoli
Lampbrush chromosome
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Left most, counterclockwise

Animal pole
vegetal pole
blastocoel
yolk plug
dorsal lip of blastopore
archenteron
Identify the Image
left most, counterclockwise

Animal pole
blastocoel
macromere
dorsal blastoporal lip
micromere
archenteron
Identify the Image

Frog Ovary (ready to ovulate)
Oocyte
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Top left, left to right

Frog Ovary
Oocyte
germinal vesicle
follicle cells
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top, left to right

Frog Ovary (maturing)
older oocytes
young oocytes
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Blastomere
Cleavage
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left, right

Blastomeres
Fertilization Envelope
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top, bottom, left, right

Blastomeres
Blastocoel
Early Blastula
Later Blastula
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top left, down the right side, bottom left

Blastocoel
Blastopore
Archenteron
Blastomeres
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Blastomeres
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left, right, bottom

Germinal Vesicle
Nucleolus
Starfish Oocyte
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top to bottom

Fertilization envelope
Perivitelline Space
Female pronucleus
Blastulation
After several cleavages a cavity forms in the center of a dividing ball
Following blastulation, an _________ of peripheral cells creates a second cavity, the ___________
Invagination
Archenteron
Gastrulation
The process of invagination
Blastocoel
Central cavity formed during blastulation
Morula
A solid ball of cells formed after multiple divisions
Blastopore
The opening to the archenteron
Perivitelline space
The separation between the egg surface and the fertilization envelope
Zygote
Fertilized egg prior to cleavage
Mesolecithal
Eggs with relatively large quantity of yolk
ex. Amphibian eggs
Oolemma
Egg plasma membrane
Grey Crescent
Sperm entry causes the outer cytoplasm of the animal hemisphere to shift 30 degrees downward on the side where sperm binding occured
The shift exposes a portion of the underlying cytoplasm on the side opposite of sperm binding
This exposed cytoplasm is termed the grey crescent
Holoblastic
having cleavage planes that divide the egg into separate blastomeres
Meridional
When a furrow bisect both the poles of the egg passing through the median axis or centre of egg
Vegetal Hemisphere
The side of the egg with the displaced yolk
Animal Hemisphere
The part of the egg that does not contain the yolk
Dorsal Blastoporal Lip
Site of involution
Yolk Plug
A region between the blastoporal lips of stationary, underlying cell not involved in the involution
Neural plate
Thickened dorsal tissue
Neural fold
The neural plate folded into a V-shape
Neural ridges
the upraised portions of the neural fold
Neural groove
The central depression in the neural fold