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Questions tagged [embryology]

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

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52 views

Ploidy of Central cell in embroidery sac

In the unfertilized embryo sac in angiosperms, is the central cell considered to be haploid or diploid? though it has two polar nuclei but both of them are haploid, so I don't think it can be ...
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27 views

Real embryo pictures: How different zones(speeman organizer, marginal zones…) are known?

In many textbook, figures of embryo are drawn,but in reality how biologist know which zone is this one of an embryo in gastrulation stade? Except the dorsal lip here i can't localize other thing.
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61 views

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

According to When a fetus hear , When a baby can hear in the womb and several other similar articles at week 18th a baby starts to hear sound. And according to How hearing works. Hearing involves ...
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1answer
49 views

Dynamic of the number of cells over time as the embryo grows

I would like to investigate the dynamic of the number of cells over time as the embryo grows. I am interested in any multicellular animal species for which we can have some data. How does the number ...
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279 views

Shell-less Chick development - Incorporation of Calcium carbonate instead of Calcium lactate pentahydrate powder?

I'm a college undergrad biology student and currently studying developmental biology as part of my curriculum. I've read a research journal titled, A Novel Shell-less culture system for chick embryo ...
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Are there any studies detailing the overall “-omics” effects of using bleach to synchronise a C. elegans population?

I wasn’t able to find papers detailing the changes in the transcriptome/proteome of C. elegans when synchronised by bleaching vs not-bleaching. Hopefully someone can point me in the right direction!
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86 views

What is the difference between Totipotent cells and Pluripotent cells? [duplicate]

I read the Wikipedia article about Cell Potency (Article on Cell Potency) Totipotency is the ability of a single cell to divide and produce all of the differentiated cells in an organism. while ...
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195 views

What are the chances that the contraceptive pill will cause death of human zygote? [closed]

The preventative pill, as I understand it, can cause zygotes to fail to attach to the uterine wall, or pry them off of it. Ignoring any and all ethical implications, what are the chances that this ...
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260 views

Why does rotational cleavage take place in mammels like humans. What is its significance? [closed]

What is the actual reason behind the rotational cleavage that takes place in humans? Why does it happen? If it doesn't occur, what will happen
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419 views

How do genes code for differences in arms and legs?

So to me it seems like arms and legs are pretty similar that they almost have the same blueprint. And if you change part of it like the number of digits, you will have 12 fingers and 12 toes. But at ...
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39 views

Are the human placenta chorionic villi and villous tree the synonyms?

Are the human placental chorionic villi and the villous tree the synonyms? Or, if not, can I say that these tissues would have practically the same gene expression profile in an RNA microarray ...
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61 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, ...
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285 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 ...
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36 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 ...
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244 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 ...
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497 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 ...
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64 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 (...
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194 views

Mutated Sperm - What happens?

I saw on TV that not all sperm are the same. Some have mutations like 2 and 3 tails? There were other mutations as well. If one of these mutated sperm actually fertilized an egg, would the embryo ...
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57 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 ?
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How scientists can be confident that human embryo tail is really a tail?

From Wikipedia: Human embryos have a tail that measures about one-sixth of the size of the embryo itself. As the embryo develops into a fetus, the tail is absorbed by the growing body. How are we ...
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1answer
226 views

What is this abbreviation CT in female reproductive system [closed]

I have this sentence in my notes Ovary is surrounded by tunica albuginea and the cortex keeps the primordial follicles. The medulla containing CT and blood vessels develop from mesonephros. I ...
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45 views

How does a cell identify itself?

In embryological development, undifferentiated cells developed into specific types. As far as I understand, a key differentiating factor is the regulation of gene expression via transcription factors....
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87 views

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

According to Spontaneous and induced fetal activity Spontaneous motor activity of the foetus depends significantly ot the foetal age; during the period between the 12th and 16th week it was ...
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27 views

I need a site for online courses

I need a site which has online courses for anatomy of limb and head and neck and also embryology, so far I have used www.coursera.org and it was really organized and helpful but unfortunately it does ...
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258 views

Embryo development terms

I'm trying to couple the following terms: cytoplasmic determinants, induction, positional information, hox genes, pattern information, morphogenisis, determination and differentiation. I hope ...
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1k views

Polar bodies fertilization

Suppose a sperm fertilized a 2nd polar body( haploid) is there a chance of somewhat normal development?
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71 views

How DNA programs the first cell in womb into a human [closed]

Sorry if you see me silly. I am just a programmer happens to be curious about biology... So far I understand how DNA make protein, how cell divides, how one composed of cells->tissues-> organs. But,...
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136 views

What is Saccus in Embryology?

The word seems to be of German origin. I have it here Saccus lymphaticus inguinalis, Saccus lymphaticus jugularis, Saccus lymphaticus posterior, Saccus lymphaticus retroperitonaealis. I ...
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862 views

Some trophoblast excreting digestive enzymes in implantation

I found this paragraph in my study materials about implantation Original Simplest trophoblast excretes trypsin related substances and embedding consists of 3 stages: The blastocyst (...
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25 views

Embryonic cells, when can you detect them in vivo? (In order to do whole genome sequencing)

I was wondering, when is it possible to extract cells (humans or mice) in order to sequence them and detect diseases. Extra: Urine of the embryo in humans is excreted in the 16th week, so I guess that ...
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36 views

Do birds require cilia for left/right symmetry during their embryological stages?

I know that in humans ciliary dyskenisia can lead to a Situs inversus, is this also the case for birds and reptilians?
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2answers
630 views

Can a viable embryo develop from the fusion of two egg cells?

For a zygote to form, two haploid gametes undergo meiosis and fuse during fertilisation. Since two egg cells (or even two sperm cells) are both haploid, is it theoretically possible for them to make ...
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2answers
47 views

Cell differentiation by non-identical copies

There are in principle two ways that two cells with the same mother cell can differentiate/specialize/diverge: Because they are not perfect identical copies (= different internal influencing factors)....
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99 views

Is endoderm visible in the germ layer?

This picture is my drawing about germ layer - not embryonic folding as I wrote initially. Where exactly is the endoderm here in the picture? The known things Ectoderm Neural tube Notochord ...
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28 views

During the cleavage cycle of a zygote what determines where the blastula starts folding?

If all of the cells divide from the same zygote it seems like they should all be the same. What causes one part of the clump of cells in a blastula to start folding over to form the mesoderm and ...
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Does the prefrontal cortex fold over the diencephalon (limbic lobe) during embryogenesis?

The frontal lobe as the top of the vertebrate brain, does it fold over the diencephalon during embryogenesis and development of the brain?
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63 views

Schizocoely and Enterocoely

In terms of phyla, mollusca, annelida and arthropoda are schizocoelic, whereas echinodermata and chordata are enterocoelic. I know that their difference lies in the formation of the coelom but how ...
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25 views

What is the outer boundary of oligodendrocyte myelination?

The sensory and motor neurons comprising the spinal cord and brain stem have the interesting property that different structural components belonging to the same neuron can occupy both the PNS and CNS. ...
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29 views

What is the optimal time to implant embryo in uterus for in vitro fertilization?

What is the best time to implant an embryo in the uterus. I was under the impression that the earlier the better and more natural, but also if you wait until the blastocyst age, it may be better to ...
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86 views

Fertilization of the human egg- where does our centrosome come from?

Is there a centrosome in a human egg cell? Is the reason why the egg cell remains paused before meiosis 2 because there isn't a centrosome, and it only divides when the sperm fertilizes it thus it can ...
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88 views

Mental Symphysis

Why dow we consider mandibular symphysis(symphysis menti) as type of Amphiarthrosis that too of symphysis variety, eventhough it lacks movement and cartilage at joint? Why don't we consider as ...
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871 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 ? ...
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179 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?
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98 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?