The study of the development of an embryo from fertilisation through to description as a foetus.

learn more… | top users | synonyms

0
votes
1answer
29 views

Conjoined twins formation theory

is it theoretically possible to take two fertilized mammalian eggs and push them together to make conjoined twins? How about forming non-identical conjoined twins?
4
votes
0answers
25 views

How only one follicle develops into graffian follicle?

I've studied that one out of many follicle develops into mature or graffian follicle. The fact which confuses me is that, since all follicles are in same ovary, close to each other with equal supply ...
3
votes
0answers
72 views

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

It is difficult to assume that the massive number of co-ordinated developmental sequences in a developing embryo is controlled by molecular signalling alone. Is anyone aware of a molecular or ...
2
votes
0answers
55 views

Is the blastocyst a coeloblastula?

A coeloblastula is that type of blastula which has a fluid filled cavity. Since the blastocyst of the mammals does too, can it be called a coeloblastula? My book however mentions the two as different, ...
1
vote
0answers
30 views

How is bilateral asymmetry determined in embryonic development?

What are the mechanisms that ensure consistent left-right asymmetric placement of various internal organs (heart, liver, etc) or consistent left-right asymmetric development of paired organs (brain, ...
1
vote
0answers
16 views

Is the amount of blood same in the pulmonary and systemic foetal circulation?

We learn that the stroke volume is the same for the right and left side of the heart. So the amount of blood in either circulations should also be the same. (is it? I myself doubt this statement. As ...
1
vote
0answers
25 views

Resources for similarity between embryos

Is there a scientific paper/reputable image resource out there which I can use that the embryos of different organisms (vertebrata) are similar in their early developmental stages(without falling into ...
1
vote
0answers
24 views

Zygote Implantation and Pregnancy Detection

In a normal pregnancy, the embryo (blastocyst) implants between 8-9 days after ovulation. My understanding is that it is able to implant because the fertilized embryo produces a hormone that triggers ...
1
vote
0answers
63 views

How often does parthenogenesis in mammals happen?

Probably everyone knows that mammals can't produce viable offspring by parthenogenesis. But there are reports of human chimeras (see: a human parthenogenetic chimaera) and it's known for mice to ...
1
vote
0answers
38 views

Do primitive lymph nodes exist in 12th week embryo?

Someone told me that primitive lymph nodes do not exist during this week. However, others say they can. Here is a picture about inguinal lymph nodes from here. No primary lymph nodes are visible ...
1
vote
0answers
19 views

Cytoplasmic determinants in amphibians

If cytoplasmic determinants are distributed before fertilisation then how can an amphibian's embryo, whose dorsal side is determined after fertilisation develop ?
0
votes
0answers
31 views

Do both the Sperm and Egg must be at exactly 7.4 pH for fertilization?

I suddenly came across this article and it says that for human conception to occur both the sperm and egg must be at exactly 7.4 pH - not 7.0, nor 7.7 but 7.4. If conception depended on such exact ...
0
votes
0answers
29 views

conjoined twins mirror image explanation

why are conjoined twins sometimes symmetrical, like organs such as liver, stomach and heart are mirror image of each other? Can you give me a hypothesis that could somehow involve primitive streaks? ...
0
votes
0answers
46 views

What tools are used in animal cloning?

So I was reading up on articles to do a project about cloning but there were no places in the article where It states the tool used to take the gene out of the nucleus and insert it into plasmids ? ...
0
votes
0answers
13 views

heterolog bodysites development?

Would it actually be possible due to unhomogen distribution of growth factors in the growth of an embryo to develop conditions like Polydactyly only on one side of the body or in an even stranger ...
0
votes
0answers
81 views

Does embryonic development mimic (partly at least) the evolution of organisms on earth?

What do we know about the forces/mechanisms which lead to this seemingly "fast forward" evolution stages of the embryo? What are the theories dealing with this idea?