Descriptive Experimental embryology help please

[eatkabab]

theres this file: http://www.ada.org/prof/ed/testing/dat/dat_test_specifications.pdf

it contains all the topics potentially covered on the DAT.

so there are two bio topics that I can't really find any study materials for.

these two topics are Descriptive and Experimental embryology. if anyone can please just list what they mean by this or where I could find some study material on the internet I'd be most grateful!!! exam is on the 30th, so please please please help :-(

I think one of these topics are covered in some problem asking about taking mesenchymal cells and putting them in a rat or chicken embryo and the animals grew teeth or somethin... or something else to do with rat and chicken embryos.


on a separate topic my Achiever bio scores have been less than stellar (17/17/15), but I feel as if the questions were just so specific that I couldn't answer them. should I be worried?

THANK YOU FOR ANNNNNNNNNNNNYYYYYYY HELP!!!!! I REALLY really REALLY appreciate it!!!

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[bounty101]

It's been a while since I took the test, but I know there's questions from embryology regarding structures and functions. For example, the different germ layers (endoderm, mesoderm, ectoderm) and what tissues they become, gastrulation, neurulation, etc.
Hopefully you're using some DAT prep guide, b/c that topics list is too broad to study from.

 

[Dotoday]

Yeah experimental embryology is a big topic right now. You definitely need to know the three germ layers (ectoderm, endoderm and mesoderm) and what tissues arise fro them. YOu must review the gastrulation movements and blastulation cleavages. Definitely the key morphogenic factors that play major roles in these processes, like Bicoid, Nanos, Notch, etc. You need to understand where do stem cells come from (the inner cell mass). Oh, definitely hox genes. Some experimental methods, like how to determine which embryological stage is it using specific staining.
These are the main topics that you need to brush up on. There is plenty of information available on the internet.
Good luck.

 

[eatkabab]

oh thank you thank you so so much!! could I please ask you to give me a little coverage on each of these topics to start me off please pleeeeeeaaaaaase. lemme know if I need to know more than this. and if there is any other topic under these I might need to know. please pleaes please!!!!!!!!


blastulation cleavages
Protostome - spiral
Duterostome - radial

gastrulation movements
epiboly - expand and thin the nascent germ layers
convergence - narrow the germ layers from lateral to medial
extension - elongate them from head to tail
any more?

key morphogenic factors: Bicoid, Nanos, Notch (are there any more? I can't seem to find these) - what is this please??
is this also called Regional Specification (process by which different areas are identified in development)
does this sound right for bicoid and nanos: The anterior/posterior patterning of Drosophila

where do stem cells come from (the inner cell mass)
Embryonic - inner mass of blatocyst 7-10 days after fertilization
Fetal - germ line tissue of aborted fetuses
Umbilical - Umbilical cord blood (similar to bone marrow)
Placenta - from the placenta (easier to harvest than umbilical)
Adult - bone marrow, blood, organs, tissues
anything else?

hox genes (homeobox genes? - involved in the regulation of development)
control segmental patterning during development (specify the anterior-posterior axis and segment identity during early development of metazoan organisms)

how to determine which embryological stage is it using specific staining - please give me a good source for this if you know any
are you talking about Precartilaginous Stage, Cartilaginous Stage, and Bony Stage?

are there any other experimental methods?

and lastly, I've heard a lot about something like implanting mesenchimal cells within a rat/chicken embryo and something happens. the question specifically tells you this scenario, than asks you something like 'what does this depict/is called/show?'


I NEVER EVER learned any of this stuff in any of my classes. thanx UCLA... :-(

PLEASE help if you can exam is on the 30th... THANK YOU SOOOO SOOO MUCH!!!!

 

[informatique]

Glad I took Embryo, but I doubt you need to know so many specifics since you don't learn all of the morphogenetic movements and genes involved in Bio 101/102. I would just know the basic events, information about stem cells, the basic layout of the body and which parts are derived from which germinal layer, how nutrients are exchanged in placental mammmals, etc.

 

[Zerconia2921]

theres this file: http://www.ada.org/prof/ed/testing/dat/dat_test_specifications.pdf

it contains all the topics potentially covered on the DAT.

so there are two bio topics that I can't really find any study materials for.

these two topics are Descriptive and Experimental embryology. if anyone can please just list what they mean by this or where I could find some study material on the internet I'd be most grateful!!! exam is on the 30th, so please please please help :-(

I think one of these topics are covered in some problem asking about taking mesenchymal cells and putting them in a rat or chicken embryo and the animals grew teeth or somethin... or something else to do with rat and chicken embryos.


on a separate topic my Achiever bio scores have been less than stellar (17/17/15), but I feel as if the questions were just so specific that I couldn't answer them. should I be worried?

THANK YOU FOR ANNNNNNNNNNNNYYYYYYY HELP!!!!! I REALLY really REALLY appreciate it!!!

Embryo

Fertilization = zygot

Zygot-morula-bastula-gasturlation = forming three germ layers (ecto, endo, meso)

Ectoderm forms skin, CNS, nails everything that you can see i.e. physical apperiances. ALSO once the three germ layers are formed nuralation occurs at the gray crestent.

Endoderm forms the lining of digestive track liver, pancrease linning of the bladder etc. Also remember when gasturlation occurs the blastopore becomes the anus in humans.

Mesoderm forms muscles, connective tissues, gonads valves, etc.

In birds the egg has polarity animal pole and the veg pole. Animal always on top and it flipped to the top after sperm fertalized it.

Aite homie i hope this helped. peace

 

[eatkabab]

this is all wonderful help. I REALLY appreciate it A LOT! ANY more information or ANY clarification would be even more appreciated. thank you guys so much! this forum has helped me out a lot while studying...

 

[doc3232]

Wikipedia!!!!

 

[eatkabab]

ya I know I love wikipedia, but its also a TON of information to sort through in 4 days...

 

[doc3232]

ya I know I love wikipedia, but its also a TON of information to sort through in 4 days...

true, good point
sdn > wiki