5 votes

How scientists can be confident that human embryo tail is really a tail?

We can be sure it's a tail because it is an extension of the vertebrae, and we define "tail" as an extension of the vertebrae, among other things. tail tāl/ noun: tail; plural noun: ...
Luigi's user avatar
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4 votes
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Can a chicken really be hatched outside of the egg?

Yes it is real, in the sense that this protocol has been through a peer reviewed journal. Note that the embryo is developing outside the shell, not outside the egg. It is the fertilized egg that ...
WYSIWYG's user avatar
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4 votes
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At what stage is the nervous system developed enough to interpret neuronal signals as 'pain'?

First, there is some confusion on your part about heart cells and pain perception. Heart cells generate an action potential intrinsically; they do not need the central nervous system to beat (your ...
anongoodnurse's user avatar
4 votes
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Does the mesoderm evolve from the ectoderm or the endoderm?

In human,the mesoderm doesnot develop from the endoderm or the ectoderm.It develops from epiblast of the bilaminar germ disc stage. During the week 3 of development, the epiblast of the disc ...
user 33690's user avatar
  • 1,955
4 votes
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How does a cell distinguish left from right?

Developing symmetry is is just a matter of Homeotic genes creating axial patterning, genes that produce a chemical gradient across a cell or group of cells. This is how developing organisms orient ...
John's user avatar
  • 14.6k
4 votes

Why can human viruses that can't infect chickens be grown in embryonic chicken cells?

The measles vaccine uses an attenuated virus: one that has been modified to reduce virulence such that it is (hopefully) no longer harmful to the host but still retains the antigenic determinants to ...
canadianer's user avatar
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3 votes

What is this part of blastula called and how is endoderm formed?

The blastocoel, as you say yourself, is a fluid-filled cavity (wikipedia) so it has no cells. Fig. 1 shows cellular and non-cellular regions of the blastocyst. Your questions on the formation of the ...
AliceD's user avatar
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3 votes
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Is a part of the spinal cord from the mesoderm?

The caudalmost part of the neural tube is formed by the caudal eminence. Isn't this mesodermal? No,the neural tube is not mesodermal at caudal end. According to Gray's Anatomy: At the time of ...
JM97's user avatar
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3 votes
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What is cytoplasmic localization?

"Cytoplasmic localization" is a very general term and it means that something is present in the cytoplasm. For instance (hypothetical but there are known examples), you can say protein-X is localized ...
WYSIWYG's user avatar
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3 votes
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Embryo development terms

When in doubt go back to definitions I say (as I am now). cytoplasmic determinants: regulatory molecules located in specific distributions around egg cytoplasm Induction: process by which the ...
SciEnt's user avatar
  • 407
3 votes

How far is stem cell research from being to generate a new organ?

Sperm can already be generated using stem cells http://blogs.discovermagazine.com/d-brief/2016/02/25/scientists-grow-working-sperm-from-stem-cells/#.V-UADBV94o8 Also, heart, liver and kidney cells as ...
alec_djinn's user avatar
  • 3,098
3 votes

Does a zygote express all genes?

The short answer is that no, a zygote doesn't express all genes simultaneously. A zygote is like any other cell, in that it represents a distinct phenotype. And like any other cell, this phenotype ...
Forest's user avatar
  • 1,879
3 votes

Has the gestation (pregnancy) period for humans always been 9 months?

human gestation period According to the link gestation period doesn't vary much between great apes. I don't see any signs that human are becoming "more complex". In fact human babies are uniquely ...
Nick Keighley's user avatar
3 votes
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How can there not be purpose movement in the fetus until week 18, when a fetus can open its mouth and suck its fingers at week 11?

Swallowing (Nishino, 2013) and sucking (rooting reflex) are reflexes. The fingers may just happen to be in the vicinity of its oral region (they often are; Fig. 1.), and oh boy are babies keen to grab ...
AliceD's user avatar
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3 votes

Can a brain process auditory signals at 18 weeks of human development?

According to a concise review by Graven & Brown (2008) the development of the auditory system (Fig. 1) in the human is as follows: 15 weeks gestational age*: structural parts of the cochlea and ...
AliceD's user avatar
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3 votes

What type of movement is "spontaneous movement" if it isnt reflex movement and it isnt purposive movement?

Although I can't read the original article in Czech, from their abstract it is clear that all they mean in differentiating spontaneous versus induced movement is whether the experimenter manipulated ...
Bryan Krause's user avatar
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3 votes

Cause of premature death in turtle eggs

Well, a real chance this is a genetic problem. How to test. For the next hatching, have some “normal” unrelated eggs nearby under the exact same conditions. If they also have higher mortality then ...
Polypipe Wrangler's user avatar
2 votes

Is there a realtime molecular clock within the genome to co-ordinate the developmental sequences in an embryo?

I think that the "molecular clock" that you refer to and the "molecular signaling" that you are skeptical of are one and the same thing. In the 1960s, nuclear transplant experiments established that ...
Maximilian Press's user avatar
2 votes
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What is the mechanism of folic acid deficiency and neural tube defects?

You are having difficulties finding the mechanism because it is as of yet unknown. Now of course comes the hard part where I need to prove that statement. Often, it's just apparent by papers not ...
YviDe's user avatar
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2 votes
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Is the thecal sac ectoderm?

The dura mater is formed by the mesoderm. The mesoderm is the middle layer of the early trilaminar embryo. The three germ layers are the ectoderm, mesoderm and endoderm, formed by gastrulation. The ...
AliceD's user avatar
  • 52.4k
2 votes

What is cytoplasmic localization?

That's absolutely terrible phrasing in that quote. I think it's referring to one mechanism of cell fate determination: a transcription factor can be transported out of the nucleus (which will result ...
Armatus's user avatar
  • 7,650
2 votes

How scientists can be confident that human embryo tail is really a tail?

FUN FACT Let's start with a fun fact! In some rare cases, humans can get born with a tail. These tails can then be removed by surgical procedure. Such procedure are quite simple and are a relatively ...
Remi.b's user avatar
  • 68.1k
2 votes

How scientists can be confident that human embryo tail is really a tail?

Well, what would you call it? Have a look at the images below (source): If you would call what other species have tails, then the human one should also be called so. After all, they are extremely ...
terdon's user avatar
  • 12.8k
2 votes

Mesoderm vs Mesenchyme- what's the difference?

Mesenchyme is the meshwork of embryonic connective tissue in the mesoderm; from it are formed the connective tissues of the body as well as blood vessels and lymph vessels. So it's a part of mesoderm
user24173's user avatar
2 votes
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What is the difference between the neural tube and the dorsal ventral cord?

The terminology can be confusing, and I suspect the question you meant to ask was: what is the difference between the neural tube and dorsal nerve cord? In vertebrates, the neural tube and the dorsal ...
Harry Vervet's user avatar
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2 votes
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How necessary is human zygote cytoplasm for generating a human?

The zygote itself is necessary because in the early embryo there is almost no transcription of its own genome, instead it uses mRNA deposited in the egg cell by the mother (see also maternal to ...
Nicolai's user avatar
  • 4,391
2 votes

Is the blastopore imaginary?

From Merriam-Webster: Definition of pore 1 : a minute opening especially in an animal or plant; especially : one by which matter passes through a membrane The blastopore is a real thing, it is not ...
Bryan Krause's user avatar
  • 45.3k
2 votes

How does gene affect organs development in eukaryotic cells?

The question is very broad and I think can only be answered in very broad terms. Proteins have metabolic functions. They do stuff! Their actions include catalyzing metabolic reactions, transporting ...
Remi.b's user avatar
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