Embryology Flashcards
An egg after it has been ovulated
ovum
An egg inside the ovary prior to ovulation
oocyte
On an ovum, there is a ________ ____, a layer that forms before ovulation, when the egg is still an oocyte, and its a protective layer made up ___ ___ / __ _____, which help care for the egg.
corona radiata, granulosa cells, follicular cells
The ___ ___ is the next layer in the ovum also called the __ ___ in non mammals, and is a thick translucent matrix of ____, which gives the layer its ____ ___ This layer contains __ ___ proteins like ZP1, ZP2, ZP3, and ZP4. ___ is the protein that allows for ___ ___ ___
zona pellucida, vitelline membrane, glycoproteins, jelly-like coating, sperm binding, ZP3, same species fertilization
The space between the zona pellucida and the plasma membrane
perivitelline space
The nucleus of an ovum is ____ and contains ____.
haploid, organelles
The sperm head contains an organelle called the ____, which is derived from the __ ___. This organelle contains __ __ that are essential dissolving the protective layers of an egg and fertilizing it. The head also contains a __ __
acrosome, golgi apparatus, hydrolytic enzymes, haploid nucleus
The mid piece of a sperm is full of ___ that surround __ __ in the cytoplasm that help move the tail
mitochondria, axial filaments
the tail of a sperm is an ___ ___ surrounded by a cytoplasm and then the ___ ___
axial filament, plasma membrane
When sperm are deposited inside the female reproductive tract, _____ occurs, specifically when the sperm enters the ___ and ___ __. This is the last required step for sperm to be ____ enough for fertilization.
capacitation, uterus, fallopian tubes, mature
The vaginal walls are extremely ____, with a pH of ____. This is detrimental for sperm, but not for __ __, which contains sperm, ____, ___ , ___, etc., which is very alkaline, with a pH of _____. Still, most of the sperm will die there.
acidic, 4.4, seminal fluid, enzymes, prostaglandins, fructose, 7-8.
The _____ ____ is added to each spermatozoa in the _____ of the male reproductive system. It protects the sperm.
glycoprotein coat, epididymus
In capacitation, once the sperm make it through the ___, the enzymes released from the ___ will digest the glycoprotein coat. Then ____ of the apical plasma membrane on the head will occur, making it easier for the sperm to release ___ _ that are needed to digest the barriers needed to fertilize the egg. Then the sperm will become ____, becoming extremely motile
cervix, uterus, destabilization, acrosomal enzymes, hyperactivated
When a sperm and egg fuse to form a diploid organism
fertilization
fertilization usually occurs in the __ __. Only ____ sperm make it to the egg there. The begin to swim through the ___ __, and onto the zona pellucida. __ ___ occurs when sperm are able to bind to __ ____ ____ there.this signifies that the two sperm and egg are the same ___. ZP3 binding triggers the release of the ___ enzyme ____ to break through the ZP
uterine tube, 300, corona radiata, mutual recognition, sperm binding receptors, species , proteolytic, acrosin,
The ___ of the sperm head will then fuse with the ovum of the plasma membrane. When this occurs, __ of the sperm enters into the egg and fuses with its nucleus. All the rest of the sperm is destroyed, including its ____. This is why mitochondria only have ___ DNA. This is when we get a __-
equator, nucleus, mitochondria, maternal, zygote
Fertilization allows the egg to undergo and complete __ __. This produces a __ __ from uneven ____ division. These structure are just discharged through the membrane as they are not ___
meiosis II, polar body, cytoplasm, viable
Fertilization also restores the _____ chromosome number. ___ ____ causes genetic variation through sexual selection
diploid, allele recombination
Fertilization also determines ____, through the chromosome that the _____ carries
sex, sperm
when multiple sperm fusing with the ovum
polyspermy
When the sperm fuses with the plasma membrane, __ ___ along the membrane open and depolarizes the membrane from ___ to ___. This prevents other sperm in the __ ____ from binding to the plasma membrane, but it only lasts for minutes, which is why is it called the __ __
sodium channels, -70, 20, vitalline membrane, fast block
In the slow block, __ __ from the ___ _ are released in to the cytoplasm of the egg and this causes the __ ___. This is when the ___ ___ are released and fused with the egg’s plasma membrane in a process called _____
calcium ions, endoplasmic reticulum, cortical reaction, cortical granuoles, extocytosis
When the cortical granules release their contents in the ___ __, It causes the area to __ and ___ itself from the plasma membrane. this is called the _ ___ or ____ ___.
pervitalline space, swell detach, fertilization envelope, fertilization membrane
cortical granuoles also inactivate the ____ ___, which prevent any remaining sperm from binding to them
zp receptors
rapid cell division without cell growth
cleavage
cells that result as a result of cleavage from a fertilized ovum
blastomeres
The indentation on the surface of the cell when it begins to divide
cleavage furrow
cleavage type where the furrow separates the cell completely into two equal blastomeres
holoblastic cleavage
cleavage type where the cell undergoes incomplete, uneven cleavage that results in different size blastomeres
meroblastic cleavage
The amount of _____ determines the type of cleavage the cell will undergo. ___ ___ do not have lots of it, and because of this, they undergo _____ cleavage. ___ and _____ contain lot of __ and __ yolk, which makes it harder for the cleavage furrow to pass through the cell. Thus they will undergo ____ cleavage
yolk, placental mammals, holoblastic, birds, reptiles, dense, thick, meroblastic
____ is what happens when a cell has decided what cell it is going to be in the future. ____ comes after and is when a ___ ___ can be seen due to the cell expressing the certain genes it decided upon.
determination, differentiation, physical change
When the resulting blastomeres are not yet decided
indeterminant cleavage
When a cell divides into two blastomeres that have already decided what cell they are going to be
determinant cleavage
In indeterminant cleavage, one cell can express all the __ __ to make a __ __. In determinant cleavage, one cell would only give rise to a specific ___ ___
required genes, complete organism, tissue type
The part of the egg that has more yolk and is slow at dividing
vegetal pole
the part of the egg where the embryo grows, has little yolk and it very active in cleaving
animal pole
The axis that divides the animal and vegetal pole
polar axis
Cleavage where the cleavage furrow is directly perpendicular or parallel to the polar axis, resulting in very organized structure
radial cleavage
____ is when there is no pattern of alignment with the polar cleavage, giving a ____ appearance, and unequal blastromeres called ___ and ____
spiral, disorganized, micromeres, macromeres
All protostomes will undergo ___, ___ cleavage, while all deuterostomes will undergo ___, __ cleavage
determinant, spiral, indeterminant, radial
All fertilized zygotes will go through multiple rounds of cleavage to form ____ blastomeres, as it travels down the ___ for implantation in the uterus. The occurs in the __ __ which prevents improper implantation. It also acts as an __ ___ against the mother’s immune’s system.
32, oviduct, zona pellucida, immunological barrier
A solid ball of cells, 16-32 blastomeres
morula
When the morula becomes a blastula / blastocyst (human)
blastulation
a hollow, fluid filled ball of cells
blastula / blastocyst
The hollow cavity in the blastula
blastocoel
When the blastula becomes a gastrula, this is called ____. This when the cells surrounding the blastocoel ______ and push inward. The opening that forms is the ___, and either becomes the mouth or anus, depending on whether it is a ___ or ____ respectively
gastulation, invaginate, blastopore, protostome, deuterostome
The gastrula continues to invaginate until it cuts down the middle, forming the ____. This will connect the mouth to the anus and thus is a primitive __ ___
archenteron, digestive system
one of the three cell types that forms from gastrulation; most primitive form of a cell line
germ layers
animals that have all 3 germ layers
tripleblastic
animals that only have an ectoderm and endoderm
diploblastic
In mammals, once at the blastocyst stage, the cells differentiate into the exterior ________ cells, and the inner __ ___ or ____
trophoblast, mass cells, embryoblast
The embryo implants into the uterus via a process called __ __, in which the embryo breaks free of the ___ ___, exposing the ___ layer
zona hatching, zona pellucida, trophoblast
the trophoblast develops into the placenta (___), and is responsible for ___ in the __ of the uterus. These cells also produce ___ ___ ___ which signals the corpus leuteum to continue producing ___ and ___ to maintain the endometrium.
chorion, implantation, endometrium, human chorionic gondaotropin, estrogen, progesterone
The inner cell mass gives rise to the __, __, __ __ and __. It is composed of two flat layers of cells, the top is called the ___, and the bottom is the ___. Together they are called the __ ___. The top layer forms a cavity called the ___, which is filled with ___ ___ and provides __ for the developing embryo. After gastrulation, it becomes a ___ _-
embryo, amnion, yolk sac, allantois, epiblast, hypoblast, bilaminar disk, amnion, amniotic fluid, cushioning, trilaminar disk
Gastrulation in mammals begins when the ____ layer thickens and forms the __ __, which as two bumps with a __ ___ in he middle. Both extend from the __ to the __ of the embryo. Then undifferentiated, migratory cells called ____, will push into the __ ___ and create the third germ layer. The top layer is now the ___, the middle layer the ___, and the bottom layer the ___
epiblast, primitive streak, primitive groove, head, tail, mesenchyme, primitive groove, ectoderm, mesoderm, endoderm
Frog eggs are ___ and deposited in water. They also have a ___ and ___ pole. They undergo ______ cleavage resulting in uneven poles
large, animal, vegetal, holoblastic
In frogs, sperm always fuse with the ____ pole in the water. This causes the __ to rotate and create the __ __, which is exactly opposite to the side the sperm enters. The grey colour is due to the mixing of the __ and __ poles and it determines the __ __ of the frog. The position and pattern will be maintained even during ___
animal, cytoplasm, gray crescent, animal, vegetal, future pattern, cleavage
A research named __ __ showed that separating the cells that formed from early cleavages could grow into normal frogs only if the cells contained a portion of the _ ___
Hans Speaman, grey crescent
The frog embryo will undergo ___, ___ like normal. Then, the cells where the grey crescent is, begin to invaginate through the __ ____of the __. This forms the opening into the ___. This will in turn, eventually displace the ___. The dorsal lip and the __ ____ eventually meet to form a circle
cleavage, blastulation, dorsal lip, blastopore, archenteron, blastocoel, ventral lip
The __ ____ grows into the blastopore and is formed from ___ cells. It is exposed on the ___ surface of the embyro. It acts as a plug between the ___ and ____, and is eventually internalized by the overlying ___
yolk plug, endoderm, vegetal, archenteron, blastocoel, ectoderm
Sea urchins are the __ __ __ and undergo ____ cleavage. Their blastula invaginates to form a ___ blastopore, and _____. This will produce ___ germ layers during gastruation
primary model species, holoblastic, circular, archenteron, 3
In birds, or egg laying animals, development happens in a large ___ ___. The egg has a large _ ___ bigger than the embryo. They undergo __ __, and have so much yolk that their embryo is squished into a __. The ____ anchors the yolk inside the egg. The ___ which is the egg white, surrounds the yolk and embryo and acts as a cushion
protective egg, yolk sac, meroblastic cleavage, blastodisc, chlaza, albumen
Birds also have a __ ___ or __ __ where cells migrate through to create the germ layers, just like humans. In contrast ___ and ___ ___ have a circular blastopore
primitive streak elongated blastopore, frogs, sea urchins
include birds, reptiles and mammals
anmiotes
includes amphibians and fish
anamniotes
The ___ or the outer membrane of the embryo is responsible for the exchange of __ and ___. In egg laying animals. Due to this, they are located right next to the __ __ and have ____
chorion, CO2, O2, egg shell, pores
The chorion in mammals, which is derived from the ____, will implant into the _______, and fuses with __ ____ to form the placenta. The placenta is responsible for __ __, __ and ___
trophoblast, endometrium, maternal tissues, gas exchange, nutrients, waste
The ____ or wastebasket in egg laying animals, stores all the byproducts pf metabolism like __ __. This is because they do not have a ___ to send wastes back to the mother. Eventually, it fuses with the _____ to assist in gas exchange
allantois, uric acid, placenta, chorion
The allantois in mammals transports waste from the embryo to the ____ and later gives rise to the __ __ , which connects the embryo to the placenta
placenta, umbilical cord
In egg laying animals, the __ __ is where all the embryo receives all its __ and ___
yolk sac, food, nutrients
In placental mammals the yolk sac is ___ because the mother is providing all the food and nutrients. However, the yolk sac aids in early __ __ __ _____
empty, red blood cell formation
The amnion in both placental and egg laying animals are filled with ___ that act as a ___ __. For animals evolved to live on land, their eggs needed the same protection that they had when the eggs were laid in ___. Thus this structure is a result of ___
fluid, shock, water, evolution
The ____ is formed during organogenesis from the ____
notochord, mesoderm
a cell influencing the development of a neighbouring cell
inductions
In neurulation, the notochord stimulates the overlying ___ to ___, which creates the ___ ___. The neural plate begins to swell and ______, forming a __ __. Eventually, the neural folds meet and pinch off, forming the hollow __ _, which will give rise to the __ and __ __
ectoderm, thicken, neural plate, fold, neural groove, neural tube, brain, spinal cord
An embryo that has undergone neurulation
neurula
In a process called____, cells next to the neural groove separate and differentiate, which as called __ __ cells. They come from the __-
delamination, neural crest cells, ectoderm
The ectoderm gives rise to the ____, including the hair, ___, ___ glands and ___ glands. It also gives rise to the ___ __ and the ___ ____
epidermis, nails, sweat, mammary, nervous system, adrenal medulla
The ectoderm also gives rise to the neural crest, and this gives rise to the bones, muscles and ___ __ of the ___, the ___, and _____, and the sensory neurons and ___ cells of the ____.
connective tissues, skull, melanocytes, odontoblasts, glial, PNS
Cells that produce dentin for the teeth
odontoblasts
The endotherm gives rise to the __ __ which creates the ___ tract, ___ tract, and ___ tract. It also gives rise to the ___ system
epithelial lining, G.I., respiratory, urinary, excretory
The endoderm also gives rise to the ___, __ and ___. As well as the __ and parts of the __-
liver, lungs, pancreas, thyroid, thymus
The mesoderm gives rise to all the ____ except the facial bones, the ___, ___ and ___, as well as connective tissues, the ____ system, the ___ system, the kidneys and ___, the ___ ___, and the ___ organs
bones, cartilage, joints, muscles, circulatory system, lymphatic, spleen, adrenal cortex, urogenital
A family of related genes that specify regions of the body plan of an embryo; ensure the correct placement of structures
hox genes
Animals are that are ___ like ____ are the result of hox genes
segmented, flies
