The process through which a biological organism grows to maturity. In certain contexts it can mean the changes the organism goes through over its entire lifetime.

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15
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2answers
911 views

Impact of Alan Turing's approach to morphogenesis

Shortly before his untimely passing, the computing pioneer Alan Turing published his most cited paper The Chemical Basis of Morphogenesis (1952). The central question for Turing was: how does a ...
14
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1answer
413 views

Fibonacci sequence in nature, truth or just wishful thinking?

I'm reading a bit on the Fibonacci sequence in nature, be it the golden ratio or the golden spiral forming over and over again in biological structures, and then I came across this online article by ...
13
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1answer
1k views

Are human bodies programmed to die?

Following from this question: What is the evolutionary advantage of death?: Is there any evidence that human bodies have systemic self-destruction built into their developmental program? I'm not ...
12
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1answer
119 views

Biological age of grafted plants

Suppose you graft a piece of an existing 'old' plant. Will it continue to grow having the same biological age as its parent? I.e., would it die at the same time as its parent? Or would the process of ...
11
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1answer
142 views

Beginning of the urogenital system

Are any invertebrate nephridia (proto/meta) homologous with vertebrate kidneys in the sense that embryologically they also begin together with the genital system? When did the embryologic association ...
10
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1answer
805 views

Could a fetus properly develop in micro/zero-gravity?

I suppose another way of looking at the question is: how important is gravity for the development of mammal fetuses? And if things would go wrong, what sort of things would they be, and what would be ...
10
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3answers
100 views

What is the smallest scale at which blood vessels, nerves and other structures are deterministic?

Super simple question, but I can't find the answer on the Internet (and I'm in a foreign country so the library is not English.) As the title says, what is the smallest scale at which blood vessels, ...
9
votes
1answer
183 views

Are there specific features of birds that cats/small predators are attracted to?

I've recently heard a podcast, in which a professor describes one of the theories as to why we like abstract art. In his talk, he mentions an experiment with seagull chicks, in which the seagull ...
8
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2answers
417 views

Why is Portuguese man o' war considered a colony?

The wikipedia entry on the Portuguese man o' war says: ... the Portuguese man o' war is ... not actually a single multicellular organism but a colonial organism made up of many highly specialized ...
8
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1answer
252 views

What prevents a pregnant woman's immune system from recognizing her fetus as nonself (and attacking)?

I'm familiar with the scenario of Rh- mother with Rh+ fetus having complications (more so after her first child), but that's not what I'm curious about. I want to know mechanistically why a pregnant ...
7
votes
2answers
766 views

Why do plants fruit?

This is a two-part question: What is the point of fruit if not to be eaten? It’s is my understanding that organisms will adapt to survive and thrive. I understand that being eaten can spread seeds, ...
7
votes
4answers
193 views

How does an embryo know where to grow limbs etc

For example you have a cell or already a bunch of cells. Those cell(s) divide and after several week you have a grown organism, for example a human with limbs, several different organs etc. However, ...
7
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1answer
53 views

Is the number of legs in myriapoda determined entirely by the genome?

Myriapoda (comprising, among others, millipedes and centipedes) can have hundreds of legs (Illacme plenipes having up to 750 legs). Interestingly, the number of legs (or leg pairs) appears to differ ...
7
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1answer
267 views

Cytoplasmic determinants - protostomes and deuterostomes

Cytoplasmic determinants are spread unevenly in the egg, and so when embryo starts forming (cells start dividing), the determinants are also unequally divided between cell. This unequal distribution ...
6
votes
3answers
223 views

Genetic effects on personality

It is said that genes are partly responsible for the choices we make in our life; our genes help to create our environment, and then that environment can influence our personality. So, beside genes, ...
6
votes
1answer
177 views

Is fluoride toxic, and how worried should I be about it?

A recent flurry of "fluoride is bad!" posts are appearing on my social network news feeds. Usually I can simply ignore them after a brief look, but this one, stemming from a recent article in The ...
6
votes
2answers
604 views

How do cells “know” what “type” to differentiate into?

I have been reading about Townes and Holtfreter's work in 1955, in which cells are dissociated from a blastocyst in an alkaline solution then mixed together and spontaneously reaggregates based on ...
6
votes
1answer
94 views

When are a female's eggs created?

Since a human woman is born with a set number of eggs, and meiosis is the process by which sex cells are produced, would meiosis in a woman happen before she is born or soon after she was born? If ...
6
votes
1answer
46 views

Why differentiated cells can't “undifferentiate” (under normal conditions)?

In a process called differentiation, the cells of the developing organism undergo huge changes, which result in cells, functioning "completely" differently. Two cells are considered to be of different ...
6
votes
1answer
24 views

How is it determined in a zygote state of foetus, that which side is mouth and which side is for anus?

After the fertilization when the zygote is in the growing state to a foetus, the main canal is introduced first, from mouth to anus. But my question is when the canal is created first how does it ...
6
votes
1answer
122 views

Bicoid regulation of hunchback

I'm learning about development via the example of Drosophila embryogenesis. I understand that bicoid regulates hunchback, among other genes. My question whether the regulation is direct or indirect? ...
6
votes
1answer
271 views

Primary cilia: what cell types have non-motile cilia that migrate?

My understanding is that there are two broad categories of cilia: motile and non-motile (also called primary. Examples of the former include sperm flagella and the cilia of epithelial cells that ...
5
votes
2answers
71 views

Why are there no artificial wombs yet?

If the conditions within the womb are mimicked, and proper amniotic fluid with constantly recycling nutrients is maintained, is it not possible to obtain an artificial womb? Is there anything missing? ...
5
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3answers
574 views

Does our eyeball increase in size as we grow?

Does the size of the eye increase as we develop from the stage the complete eye first forms to infancy and then to adulthood ?
5
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1answer
98 views

Free-flowing cells and those that are stuck together?

I've been thinking about the development of an embryo from the zygote stage. How is it that when cytokinesis takes place at that stage, the cells all stick together in a little ball, but later in ...
5
votes
1answer
108 views

Is there any scientific evidence that a human has ever grown a third set of teeth?

This is about the possibility (or lack thereof) for a person to re-grow a new "permanent tooth" or set of teeth, to replace the teeth that grew after their milk teeth fell out. I had earlier seen ...
5
votes
1answer
254 views

Are fish and reptilian scales homologous?

Wikipedia: Fish scales are dermally derived, specifically in the mesoderm. This fact distinguishes them from reptile scales paleontologically. So aren't reptilia scales also dermally derived?
5
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2answers
584 views

What metabolic activities are performed by a developing human fetus's liver?

I understand that organ function varies with the stages of development. Does a fetal liver EVER perform lipogenesis, gluconeogenesis, make bile, etc? Or does it only begin performing these actions ...
5
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1answer
47 views

Components of the concept of Developmental Noise?

Developmental noise is a concept that correspond to the amount of possible phenotypic variance of a given genotype in a given environment. Intrinsic noise (aka Cellular noise) is a component of ...
4
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2answers
113 views

Are there special constants in biology that define organism's morphology?

In math, there are special numbers, like Pi (3.14159...) and e (2.71828...). In chemistry, there's numbers like avogadro's number (6.0221413e+23). For example a circle can be defined in terms of 2 * ...
4
votes
2answers
256 views

How does the colinearity of the HOX genes determine the body plan of an organism?

I was recently reading about colinearity in the HOX genes that give an organism its high-level body plan (where the order of the HOX genes on the chromosome follow the head-to-tail order of body ...
4
votes
1answer
193 views

How does sex differentiation work in Paracerceis sculpta, the sexually tetramorphic isopod?

Paracerceis sculpta is a marine isopod species known for its unusual reproductive strategy: female: medium-sized; lives in harems run by an α male α male: large; keeps a harem of females β male: ...
4
votes
1answer
103 views

How animals maintain their body shape after development to maturity?

I've recently read a book on evolutionary-developmental biology for laymen, and it described how a fetus is progressively divided into more refined zones of genetic activity. These zones, kinda like ...
4
votes
2answers
454 views

Question about cell signaling pathways (RTK, Jak-Stat, SMAD, etc)

I am in an embryology course right now and we've just started covering cell-cell communication in development. We were talking about the roles of the various cadherins and their discoveries but we got ...
4
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1answer
90 views

How does aging affect fingerprint?

Do fingerprints change as we grow from child to adult? Most notably, what is the effect of the increase in surface area of palms and fingers on the finger print? Does the finger print simply increases ...
4
votes
1answer
459 views

Does Amphibian embryo's blastocoel become a primitive yolk sac without yolk?

The mammalian blastocoel becomes yolk sac without yolk according to my professor. I have not found any evidence that such a thing happens in amphibians like frog. I need to be able to compare and ...
3
votes
1answer
130 views

Method to recognize the age of a firebug from the pattern on its back

Can I recognize the age of a firebug from the pattern on its back? If yes, what pattern shows what age/stage? Below is what I extrapolated from Wikipedia, but is there a more precise scale with more ...
3
votes
1answer
50 views

Where can I find a full genealogy of human cell types?

It is said on Wikipedia, that the precursor of blastocyst is a morula, and that the precursor of morula is a zygote. This gives us the part of genealogy tree of cell types. Unfortunately, no full ...
3
votes
2answers
35 views

What would happen if there were no SOX9 in an XY human?

Would testes be produced? If SRY is functional, can it produce other proteins that can direct the production of testes, which may or may not be sterile?
3
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1answer
40 views

What are the application areas of Pattern formation studies specific to biology? [closed]

I was reading about reaction-diffusion processes, morphogenesis concept by Alan Turing and works of Murray in describing pattern formation on animals etc. But one question which came to my mind was ...
3
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2answers
179 views

Why ducklings are yellow?

Why ducklings are yellow, what the evolutionary background for this? How could it help to survive? UPDATE I agree with comment below, I did remember then that ducks are wild animals too (when I ...
3
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2answers
395 views

which exact mechanism triggers the first cell differentiation after n divisions?

I would like to understand which mechanism triggers the first cell differentiation after n divisions. I read previous articles on SE and Wikipedia articles on cellular differentiation and ...
3
votes
1answer
20 views

How long do zebra fishes remain transparent?

As larva, zebra fishes are transparent, at least up to 5-6 days. I wonder what would be the upper limit of the transparent period. This is of relevance considering purposes for imaging. The question ...
3
votes
1answer
61 views

What happens to human dopaminergic reward system once a teenager becomes adult?

I've recently heard a podcast which explained teenage impulsivity and novelty seeking in part by "Lowering the baseline dopamine activity in the reward system" "Increase in dopaminergic reward in ...
3
votes
1answer
136 views

Drosophila melanogaster eclosion

Is there any published data which shows the number of Drosophila melanogaster fruit flies eclosing (hatching out of the pupae) against time since egg oviposition? I'm thinking there should be ...
3
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3answers
2k views

Why does the apex of the human heart usually point to the left?

In the majority of human beings, the apex of the heart (left ventricle) points towards the left side of the body. Sometimes however (approx. 1/12000 births), a person is born with a condition known ...
3
votes
0answers
42 views

How does an organism know when to stop growing, whether it is already on the outermost layer? [closed]

When a multicellular organism is under its development how does the current outermost layer of cells "know" that they should not divide furthermore, as their bodyplan coded into DNA is already ...
3
votes
0answers
60 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
1answer
86 views

What happens to our umbilical cord internally as we age?

I was always curious as to if or how much of the internal structure or workings of the umbilical cord are still in existence as we age. What happens to it over time? The wikipedia article naval ...
2
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1answer
35 views

How do processes of one osteocyte establish contact with processes of the adjacent cells within the mineralized matrix?

Are the processes and canaliculi formed and contacts established after the osteocytes are embeded in the matrix or are they formed during the embedding process itself. Is there any evidence to suggest ...