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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161 views

Any examples of an organism's life cycle where the reproductive stage occur before the 'adult' stage?

Most life cycles we knew of consist of a juvenile stage (e.g. larval for insects, sporozoite for some intracellular parasites), a reproductive stage and an adult stage. Usually the reproductive stage ...
4
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2answers
917 views

Could we slow down life? [closed]

As far as I know there is no absolute time measurement (one that would measure time in a non-environment-dependent fashion) in any life form. Only such time measurements exist, which are dependent ...
3
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1answer
37 views

Cause of Crease in Drupe Fruit

What causes the crease through the pericarp of a drupe fruit (peach, nectarine, olive)? It may just be in exocarp as @Ilan pointed out, but I assumed (perhaps wrongly), that the division continued ...
10
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1answer
120 views

Do babies resemble their father?

An often heard theory is that newborns and babies resemble the father more than the mother, a theory apparently ignited by a Nature paper by Christenfeld and Hill (1995). Figure 1 shows one of the ...
6
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1answer
33 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 ...
2
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2answers
60 views

Recommend good conversational books to learn about cell and developmental biology or biochemisty?

I'm an engineer by training and teaching myself the basics of cell and developmental biology. I'm using Scott F. Gilbert's Developmental Biology and Alberts' Essential Cell Biology right now, and they ...
2
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0answers
9 views

variance in zygotic gene expression across species

I found this review on the Maternal-to-Zygotic transition (MZT), describing how developmental control switches from maternally deposited RNAs to zygotic expression. I was struck by figure 1, and the ...
6
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1answer
49 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 ...
2
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1answer
31 views

Cysticercoids of Eucestoda

I have found the following pictures representing cysticercoids of Eucestoda. If I correctly understand the right part of the picture, I would say that the development of the scolex is portrayed on ...
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19 views

Is this a legitimate teratoma for a human pluripotent stem cell assay?

I can't quite make out this teratoma: ...
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1answer
53 views

How detachment/separation works in biology?

It might be a strange question, but I'm interested in the mechanics of separation/detachment during asexual reproduction, for example when an organism reproduces by budding (I don't mean cellular ...
4
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0answers
55 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 ...
5
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2answers
77 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? ...
4
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1answer
109 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 ...
2
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1answer
124 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 ...
3
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1answer
24 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 ...
2
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0answers
14 views

Why there are two rounds of cytosine de-methylation in mammalian development?

I assume that the key biological meaning of cytosine de-methylation during germline development in germline progenitor cells is to reset imprinted genes and then set methylation pattern on these genes ...
5
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1answer
136 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 ...
6
votes
1answer
96 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 ...
7
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2answers
807 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, ...
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2answers
62 views

Can you build muscles from watching point of view videos of people weightlifting?

According to this, "new research has found that viewing other people exercise actually increases your heart rate and other physiological measures, just as if you were working out yourself". This got ...
12
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1answer
126 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 ...
1
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1answer
318 views

What is the difference between embryology and developmental biology?

The question is quite explanatory in it self, I used to think that both are same but then find somewhere that embryology is a part of developmental biology, can somebody please elucidate?
5
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1answer
300 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?
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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?
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4answers
208 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, ...
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0answers
109 views

How many proteins are synthesized in human body throughout life?

My idea to calculate this is: Define up to what age will do the calculation. (for instance 60) Determine how many cells born and died up to that point in life. (by type of cell) Determine how many ...
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1answer
136 views

Are there anatomical differences between male and female mammal brains before action of hormones?

is there any evidences of these differences during development stages prior to hormone driven sexual differentiation? mice studies ?
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1answer
44 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 ...
5
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1answer
49 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 ...
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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, ...
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2answers
89 views

Questions about the Evolution Theory [closed]

I'm trying to understand more about evolution theory. (I am coming from a mathematical background) What i understand till now is that the "improvement" of the dna is a purely random development and ...
7
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1answer
54 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 ...
6
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1answer
181 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 ...
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1answer
50 views

What does “developmentally programmed” mean?

What does the term "developmentally programmed" mean? I can't seem to find a definition anywhere. What would the alternative (i.e. not developmentally programmed) imply?
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2answers
118 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 * ...
3
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1answer
62 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 ...
2
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1answer
196 views

Development of vitreous humor

I have tried reading about development of vitreous humor but it is all very confusing. When does it first developed ? Does it renew itself ? Please provide reliable sources..
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3answers
671 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 ?
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1answer
198 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 ...
11
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1answer
150 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 ...
8
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2answers
445 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 ...
3
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1answer
142 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 ...
4
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2answers
272 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 ...
3
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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 ...
7
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1answer
269 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 ...
2
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1answer
524 views

How many consecutive cell divisions are required to form the adult human body from the single cell zygote?

The preferred question would have been what is the total number of cells in a full term human foetus and how many cell divisions are required to reach that number. However estimates of total cell ...
2
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1answer
37 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 ...
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2answers
44 views

Which part of the genome are the developmental sequences of embryogenesis located?

Which part or parts of the the genome are the sequences located. Are they spread across the chromosomes? If so how are they accessed sequentially with precision during embrygenesis?
3
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2answers
232 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 ...