Zoology 523 Exam 3 ACTUAL UPDATED Questions and CORRECT Answers
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Terms in this set (346)
pharyngeal stage stage after gastrulation; embryo has: pharynx, central neural tube, notochord,
somites, head region
all vertebrate species start out developing the same exact way
general stages of development 1) fertilization, 2) cleavage, 3) gastrulation, 4) organogenesis, 5) metamorphosis, 6)
gametogenesis
fertilization fusion of mature gametes
cleavage series of rapid cell divisions during which the cytoplasm is split between smaller
daughter cells (blastomeres)
gastrulation slower cell division and dramatic cellular rearrangements
at the end of gastrulation, the gastrula has all 3 germ 1) ectoderm, 2) mesoderm, 3) endoderm
layers
3 friends who established embryology Christian Pander, Karl Ernst von Baer, and Heinrich Rathke
who discovered the germ layers? Christian Pander
ectoderm outer layer = skin, brain, neural crest
mesoderm middle layer = blood, heart, kidney, gonads, bones, muscles, and connective
tissue
endoderm inner layer = digestive tube and its associated organs including the lungs
what germ layer gives rise to neural crest? ectoderm
the germ layer gives rise to the central nervous system: ectoderm
organogenesis formation of tissues and organs; many organs actually contain cells from multiple
germ layers
the notochord rod of mesodermal cells; begins developing at 17 days in humans; gone by 7-10
weeks; signals overlying ectoderm to become the nervous system
metamorphosis process of changing from immature to sexually mature organism
, gametogensis process of producing gametes for reproduction; germ cells are gamete
precursors; set aside normally during very early development; different than
somatic cells which are all other cells of the body
important steps to remember about meiosis: 1) chromosomes replicate prior to cell division so each gene is represented 4
times
2) replicated chromosomes (chromatids) are held together by the kinetochore
and all 4 chromosomes pair together
- recombination occurs
3) 1st meiostic division = separate chromatid pairs
4) 2nd meiotic division = splits the kinetochore so each chromatid becomes a
single chromosome
RESULT = 4 germ cells with a haploid nucleus
the germ layers are formed during which general stage gastrulation
of development?
what did von Baer do? 4 laws of vertebrate development
first von Baer law - the general features of a large group of animals appears earlier in development
than do the specialized features of a smaller group
- all developing vertebrates look very similar after gastrulation and only diversity
later
second von Baer law - less general characters develop from the more general, until finally the most
specialized appear
- early on, all vertebrates have a similar skin. specializations such as scales,
feathers, hair develop later
third von Baer law the embryo of a given species, instead of passing through the adult lower (simpler
anatomically) animals, departs more and more from them
fourth von Baer law therefore, the early embryo of a higher animal is never like a lower animal but only
like its early embryo
how does the blastula become a gastrula which becomes a complicated series of cell movements and shape changes allow the formation
an adult? of the axis
fate map identification of groups of cells in the gastrula that will become a particular tissue
in the adult
method 1: fluorescent dye labeling step 1: inject cells with fluorescent tracking dye (green)
step 2: see where they go!
method 2: chimeric organisms (quail chick chimeras) step 1: transplant cells from quail embryo into chick
step 2: see where they go!
- how do we identify quail cells in a chick?
1. differences in nuclear DNA condensation
2. quail-specific antibodies
- immunohistochemistry
C
Terms in this set (346)
pharyngeal stage stage after gastrulation; embryo has: pharynx, central neural tube, notochord,
somites, head region
all vertebrate species start out developing the same exact way
general stages of development 1) fertilization, 2) cleavage, 3) gastrulation, 4) organogenesis, 5) metamorphosis, 6)
gametogenesis
fertilization fusion of mature gametes
cleavage series of rapid cell divisions during which the cytoplasm is split between smaller
daughter cells (blastomeres)
gastrulation slower cell division and dramatic cellular rearrangements
at the end of gastrulation, the gastrula has all 3 germ 1) ectoderm, 2) mesoderm, 3) endoderm
layers
3 friends who established embryology Christian Pander, Karl Ernst von Baer, and Heinrich Rathke
who discovered the germ layers? Christian Pander
ectoderm outer layer = skin, brain, neural crest
mesoderm middle layer = blood, heart, kidney, gonads, bones, muscles, and connective
tissue
endoderm inner layer = digestive tube and its associated organs including the lungs
what germ layer gives rise to neural crest? ectoderm
the germ layer gives rise to the central nervous system: ectoderm
organogenesis formation of tissues and organs; many organs actually contain cells from multiple
germ layers
the notochord rod of mesodermal cells; begins developing at 17 days in humans; gone by 7-10
weeks; signals overlying ectoderm to become the nervous system
metamorphosis process of changing from immature to sexually mature organism
, gametogensis process of producing gametes for reproduction; germ cells are gamete
precursors; set aside normally during very early development; different than
somatic cells which are all other cells of the body
important steps to remember about meiosis: 1) chromosomes replicate prior to cell division so each gene is represented 4
times
2) replicated chromosomes (chromatids) are held together by the kinetochore
and all 4 chromosomes pair together
- recombination occurs
3) 1st meiostic division = separate chromatid pairs
4) 2nd meiotic division = splits the kinetochore so each chromatid becomes a
single chromosome
RESULT = 4 germ cells with a haploid nucleus
the germ layers are formed during which general stage gastrulation
of development?
what did von Baer do? 4 laws of vertebrate development
first von Baer law - the general features of a large group of animals appears earlier in development
than do the specialized features of a smaller group
- all developing vertebrates look very similar after gastrulation and only diversity
later
second von Baer law - less general characters develop from the more general, until finally the most
specialized appear
- early on, all vertebrates have a similar skin. specializations such as scales,
feathers, hair develop later
third von Baer law the embryo of a given species, instead of passing through the adult lower (simpler
anatomically) animals, departs more and more from them
fourth von Baer law therefore, the early embryo of a higher animal is never like a lower animal but only
like its early embryo
how does the blastula become a gastrula which becomes a complicated series of cell movements and shape changes allow the formation
an adult? of the axis
fate map identification of groups of cells in the gastrula that will become a particular tissue
in the adult
method 1: fluorescent dye labeling step 1: inject cells with fluorescent tracking dye (green)
step 2: see where they go!
method 2: chimeric organisms (quail chick chimeras) step 1: transplant cells from quail embryo into chick
step 2: see where they go!
- how do we identify quail cells in a chick?
1. differences in nuclear DNA condensation
2. quail-specific antibodies
- immunohistochemistry
