proto vs deutero
cleavage patterns and associated control processes
proto vs deutero
fate of blastropore
proto vs deutero
coelom formation
cleavage
___ refers to the initial cell divisions of the embryo
cleavage
during ___, a large cell is mitotically cleaved into many smaller cells without growth of the cytoplasm between cell division, thus the cell gets smaller
protostome
__ show a spiral cleavage pattern
protostome
___ plane of division is diagional to the vertical axis of the embryo
deuterostome
__ have a radial cleavage pattern
deuterostome
___ plane of division is parallel or perpendicular to the vertical axis of the embryo
protostome
___ have a determinate type of development in which the "future" of the embryonic cells is determined very early . consequently, if a cell of a embryo of a protostome is damaged early in development, the embryo would be unable to "regulate" or compensate
deuterostome
__ have an indeterminate type of development in which developmental instructions arise graduallly. the fate is not "determined" early on
gastrulation
during ___, cells migrate fromt he surface inward to form a cavity, the archenteron, that opens to the outside through the blastopore. the three germ layers also form at this time
gastrulation
during ___, one can beging to see the formation of the basic animal body plan, a tube (GI tract) within a tube (the outside body)
archenteron
the ___ opens to the outside surace through the blastopore. in chickens and humans, the ___ form a primitive streak
deuterostome
the blastopore in ___, the blastopore will become the anus, which the mouth arising second
protostome
the blastopore in ___, will eventually become the mouth
gastrulation
coelom formation occurs during ___
protostome
in ___, solid masses of mesodermal cells split to form the coelom
deuterstome
in ___, an outpocketing of the archenteron forms the coelom
spermatagonium
__ is a specialized cell that uses mitosis to generate more spermatagonia. internal and external signals trigger a subset of these to divide meiotically to produce gametes
primary spermatocyte
prior to meiosis DNA replication occurr and these cells are known as ___. they are diploid (2N) because ther are 2 complete sets of chromosomes, but each chromosome is composed of sister chromatids
primary spermatocyte
___ has twice the usual DNA content of a typical 2N cell and 4 times the amount of DNA as a gamete. if a gamete has 1C DNA then a ___ has 4C DNA
secondary spermatocyte
after completing the first meiotic division ther eare two daguther cells, each called a ___
secondary spermatocyte
__ each is haploid (1N) because it contains only one full set of chromosomes, but it is 2C because each chromosome is composed of sister chromatids. hence, the ____ is 1N and 2C
seminiferous tubules
site of spermatogenic cells where spermatogenesis occurs
spermatogenic cell
various stages of cells during spermatogenesis. the outer cells are the least developed, and as they mature they are pushed into the lumen (cavity) of the tubule
spermatid
immature sperm that lack a flagellum and are found in the lumen of the seminiferous tubule. once a flagellum has been added they are called spermatozoa but they still need additional maturation
interstitial/leydig cell
small clumps of cells between the seminiferous tubules that produce testosterone
epididymis
the ___ is a coiled tube ont he surface of the testis. sperm maturation occurs here
vas deferens
the ___ is a duct that is the distal extenstion of hte epididymis
oogenesis
___ resembles spermatogenesis but there is unequal cell division
primary oocyte
after dna replication, but prior to the first divison of meiosis, you have a ___
secondary oocyte
after the completion of the first meiotic division ther are two daugther cells. the larger cell is the ___, the smaller cell is the polary body. each is 1n, 2c.
secondary oocyte
the __ undergoes a second meiotic division to produce an ootid and another polar body. each is 1n, 1c.
ootid
___ is the larger cell and will mature into an ovum
estrous cycle
non primate mammals, like the rat, hve an ___ with cyclical changes. in particular, the females are receptive for mating only at specific intervals. a haloid ovium is released during ovulation
menstrual cycle
humans, being primates, undergo cylical changes during ___.
menstruation
___ refers to the shedding of the endometrium, the lining of the uterus. a secondary oocyte, and not an ovum, is released at "ovulation". in humans, the second dvision of meiosis is actually stimualted by the fusion of sperm and egg cell membrane
gametogenesis
the ovary undergoes dramatic short term cyclical changes associated with ___
primary oogonia
cells capable of undergoing mitosis or meiosis
primary follicle
a small, single-layered cluster of cells surrounding a developing ovum. as the follicle develops it secretes nutrients for the ovum; in addition, the follicular cells secrete estrogen
growing follicle
follicles of different sizes with several layers of cells at diffrent stages of oogenesis
mature follicle
large follicles that bulge from the surface. the ovum is contained within a mass of small, follicular cells that protrude into an extensive, fluid-filled cavity known as the antrum
ovum
an egg cell contained within a mature follicle.
corpus luteum
large mass of cells formed from the follicle after ovulation that secretes estrogen and progeterone
fast block
within a few seconds there is a depolarization of the egg membrane potential. this prevents additional sperm from prenetrating the egg cell membrane and prevents polyspermy. this ___ cannot be maintained for a very long because of hte huge change in membr
slow block
after one minute cellular events cause the fusion of cortical vesciles with the egg cell membrane and hte vitelline membrane. additionally, enzymatic reactions results in the hardening of the vitelline membrane. it is now known as the fertlization membran
vegetal pole
the __ (lighter color) contains most of the yolk, and therefore, is heavier. when the eggs are lay the eggs rotate such that the vegetal pole is in contact with the substrate
holoblastic
in ___ cleavage, the cleavage plane extends entirely through the zygote
meroblastic
in ___ cleavage the cleavage plane does not extend entirely through th zygote.
blastula
the __- stage is characterized by the formation of the blastocoel, a fluid- filled cavity
gastrula
the __ stage is characterized by the cells invaginating inward toward the blastopore, the yolk plug is visible in the blastopore, the three germ layers form during gastrulation
neurulation
__ is the process by which the nervous system is formed. the neural plate forms a neural tube, note the large ridge (the neural tube) located on one side. the notochord (a rod like support characteristic of chordates) is also formed
amnion
in reptiles, birds, and mamals, the embryos devleop in a watery cavity called the ___
uterus
mammals, are enxased in the __ and nutrition is obtained via maternal circulation
shells
birds and reptiles are encasedwithin ___, and their nourishment must come from the yolk and albumen within the egg
fertilization
the ovum is released from the ovary aand is swept into the oviduct by cilia lining the oviduct. if __ is going to occur, sperm must be deposited in the female reproductive tract by the rooster. the sperm then swim into the oviduct and fertilize the ovum.
air space
a small ___ is present near the developing embryo.
meroblastic
due to the huge amount of yolk, cell division is ___.
germ layers
in addition to the embryo proper, ___ also generate lateral body folds that develop into extra-embryonic membranes
yolk sac
the __ form first and encloses the yolk. eventually, the ___ will surrond the albumen as well. it becomes highly vascularized and helps with the uptake of nutrients. there is an exchange of nutrients between the cells of the yolk sac and the cells that li
amniotic membrane
the __, filled with amniotic fluid, immediately surrounds the developing embryo. the amniotic fluid mechanically cushions the developing embryo and helps to prevent desiccation.
allantoic membrane
the __ buids off of the midgut and is directly connected tot he developing embryo. portions of it extend outward from the developing embryo. with time the ___ continues to enlarge, because of the allantoic cavity (allanotis) becomes a storage reservoir fo
uric acid
chickens store their wastes mostly as ___ eventually most of hte allantoic membrane will fuse witht he chorionic membrane and together they will be responsible for most of the gas exchange across the egg shell.
chorion
the fourt extraembryonic membrane, the __ eventually surrounds everything.
bulge
each __ in the uterus represents a single embryonic "unit" which consists of the embryo and the associated placental structures. their size will obviously depend on their stage of development
embryo
the __ is contained within a sac, the amniotic cavity, which is enclosed by the amniotic membrane.
placenta
the ___ is the region where the extra embryonic tissues of hte embryo are intimately connected with the maternal tissues of the uterine wall. hence, the placenta is composed of both embryonic and maternal components
allantois
extra-embryonic membrane used in respiration and excretion
amnion
an extraembryonic membrane, encloses the amniotic cavity which is fluid filled and protects the embryo
archenteron
primitive gut
blastocoel
cavity formed during the blastula stage
blastomeres
cells in early embryo
chorion
an extra embryonic membrane that is most external, fuses with the allantois in placental organisms to formt he placenta
enterocoelous development
formation of the coelom by out pocketing of mesodermal buds from the archenteron
fertlization membrane
describes the vitelline membrane after is has separated from the egg membrane due to deposition of proteins in the space between the vitelline membrane and the egg membrane
gamete
a sexual reproductive cell
gastrula
the stage during which the primitive digestive system is formed
gastrocoel
early coelom
holoblastic
type of cleavage where the entire egg is subdivided
meroblastic
type of cleavage in which the division plane extends only through part of the egg
metamorphosis
transformation of an immature animal into another developmental stage during which radical changes occur
morphogenesis
the processses by which the embryonic tissue layers are shaped into organs
neurula
developmental stage characterized by the formation of the neural tube
ovum
female gamete
spermatazoa
male gamete
vitelline
membrane surrounding the ovum fertlization
zygote
the fertilized egg