Questions tagged [development]
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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Have elephants (or any species other than humans) been known to cover their dead?
I was just reading this blog on HarperCollins website about 5 animals that grieve. Of elephants, the following claim is made:
They bury their dead and pay tribute to the bodies and to the bones. [my ...
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How does embryology provide evidence for evolution?
I am not a biology student, I just have a profound fascination and appreciation for biology, and from time to time I like to read and watch videos about it.
I was reading about evolution when I came ...
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Larval abalone devlopmental times - what does ~ °C.days or °C hr-1 mean
I'm looking a number of papers on abalone larval development and the term °C.days or °C hrs-1 keeps coming up. The numbers before these terms are much larger than they would be if this term actually ...
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A question on cell division rates
It seems that in the adult human body the rate of cell division should be approximately equal to the rate of cell death, but how is this reconciled from the developmental phase where a single germ ...
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How does a turtle develop inside its egg?
This is related to Cause of premature death in turtle eggs, for those interested.
I have noticed that Kinosternon spp. eggs have three layers:
hard outer shell
white opaque membrane (like the one you ...
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Are there any species whose cells do not copy the DNA that has been inactivated during cell differentiation?
According to this paper, the ATP cost of a having (not counting transcribing) a gene in a diploid eukaryote is about $5\times 10^3$ ATP per base pair, while the lifetime ATP usage of a mono-cellular ...
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Do the cells of any multicellular lifeforms discard their genetic material after differentiating?
There are many types of cells which will never again divide. Some of them may not need DNA to perform their function. Are there any cases where the DNA is discarded after a final differentiation?
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Do we know the genome contains all the information necessary for embryonic development?
Since high school biology I've assumed that all information necessary for creating an organism is found in its genome. As Nature's Scitable site says:
Deoxyribonucleic acid, more commonly known as ...
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Which varieties of Aurelia aurita do not have a polyp phase?
According to this "In some Aurelia aurita, the polyp stage does not exist.", but they don't cite anything. Is there a resource detailing life cycles of various jellyfish or do I have to find ...
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Why does water damage the lungs but amniotic fluid doesn't?
I've read that near-drowning causes lung damage due to water inhalation. How come this is not the case with amniotic fluid? Taking this further, would lukewarm purified oxygenated water cause damage (...
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What is the purpose of interkinetic nuclear migration during neurogenesis?
I am reading about neurogenesis and I am learning about the different types of neural stem and progenitor cells (neuroepithelial cells, radial glial cells and basal progenitors). I have read that ...
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How can I decrease the generation time of Drosophila melanogaster?
I have a gene deletion strain of Drosophila melanogaster made with CRIPR/Cas9, and now I have to clean the background of this strain (TM6C balancer background) by making backcrosses with wild type. ...
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Does a brown Pieris brassicae chrysalis indicate it is dead?
I have been breeding Pieris brassicae larvae in a glass tank indoors for my own personal observation. One of them, after the fifth instar, has moulted into a chrysalis. After 5 days of development in ...
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What is tissue patterning?
This term gets thrown around sometimes in biology articles, and I have a rough idea of what it is: during embryonic development, the tissue differentiates in a certain spatial configuration. Wikipedia ...
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cell proliferation assays for research proposal
I'm an undergrad Biology student and I'm working on a research proposal for a certain course. I need help or guide on cell proliferation assays. I have a target gene , recent papers show that this ...
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What is meant by pro-acinar cell?
What is meant by "pro-acinar cell" in the following sentence? progenitors/precursors?
A transient decline in Neurog3 expression from E11 to E12 coincides with peak segregation of MPCs into ...
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Spontaneous generation of fruit flies
I live in the South of England. It is currently winter.
Whenever I buy bananas, even one, if I leave the discarded banana peel in my kitchen, within hours or even minutes, there is a cloud of little ...
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Development of radial symmetry in starfishes and other animals
How does nearly perfect radial symmetry arise in an animal like the starfish? My confusion lies in the fact that cells are fluid & amorphous, & that these characteristics seem to make it ...
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What is the evolutionary advantage of breathing and heart beats syncing between partners?
I recently read that partners who are close to one another usually when touching have their heart beats and breathing in sync. Why does this occur? What is the benefit of it occurring? How does this ...
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Are there any real life instances of kidney organoid transplants in human?
Googling the terms "kidney organoid", "artificial kidney" etc. shows quite a huge amount of research papers regarding studies about kidney organoid synthesis from pluripotent stem ...
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Why can human viruses that can't infect chickens be grown in embryonic chicken cells?
Embryonic chicken cells are commonly used in vaccine production. The viruses are grown in chicken eggs, or in embryonic cells taken from those eggs, and then inactivated or attenuated to produce the ...
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Do patella bones form in people born with the inability to walk?
The patella is a sesamoid bone that typically doesn't completely from and ossify until ~3-6 years of age (e.g., Source). My long-standing understanding (supported by a claim in Saladin's college A&...
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Germ cells vs. gametes
Naively, I thought that germ cells are diploid (in diploid species like human/mouse at least). Then, germ cells undergo meiosis and become haploid. I thought this was the critical change that defined ...
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Do babies have a fight or flight response?
Do babies react in the same way as young children and adults in regards to the fight or flight response? If they do not respond in a similar way or don't have a fight or flight response at all then at ...
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Can the axial length of the human eye decrease?
I understand that the axial length of the eyeball grows until you are around 20 years of age, which is why hypermetropia decreases with age but myopia doesn't. My question is: can the axial length of ...
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What is the difference between floral primordia and floral buds?
As we know an axillary bud differentiates to form a floral bud, but what is a floral primodium?
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Can hand sanitizer kill a fertilized human egg cell?
If you took a human egg cell that was fertilized in vitro and sprayed some hand sanitizer on it would it die?
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Why do Centipedes always have an odd number of pairs of legs?
Furthermore, centipedes are within the Myriapoda, a subphylum of arthropods which also contains millipedes. Do millipedes also have an odd number pair of legs?
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Are there any known consequences of the right-handedness of the DNA double helix?
In this article it is suggested (without evidence) that the right-handedness of DNA may be the cause that "kick[s] off asymmetry in the early embryo [of snails]".
On the one hand we know that ...
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Why does it take so long for the human brain to develop from an evolutionary point of view?
I have read that it takes about 25 years for the brain to be fully developed.
Coincidentally, humans from the Neolithic and Bronze Age had a very short life expectancy, in fact most of their life ...
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How much blood do we have when the heart first starts to beat?
How much blood do we have when the heart beats for the first time?
It should be between the third and fourth week of embryonic life.
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Reflex muscular activity in three months old fetus
At the end of the third month, reflex activity can be evoked in
aborted fetuses, indicating muscular activity
This quote is from Langman's Medical Embriology.
Have I misunderstood it or it is ...
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What is Balbiani's vitelline body function?
I tried searching on Google Scholar but I found little to no information about this Balbiani's vitelline body.
I don't even know why it is called vitelline...I've been taught that it can be seen ...
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Do any non-human species have juveniles that cannot communicate with adults?
Human babies take 1+ years to begin learning how to speak (though sign language can be learned a bit earlier1).
I know that cries, yells, and other non-linguistic sound are a simple form of ...
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How many times have the cells in a human body divided?
Every single cell in a multicellular organism can in principle trace its "ancestry" back to the zygote through a continuous chain of cell divisions. How many divisions have occurred in a typical cell ...
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How do schistosomes find and attach to human skin?
Schistosomes are parasitic flatworms that have a snail intermediate host and a human definitive host.
After developing in the snail, they (cercariae stage) escape into the water and can attach to the ...
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How does X chromosome monosomy occur
I want to understand how Turner syndrome - monosomy X - occurs at the molecular level. The NIH mentions that there are cases of both complete monosomy and of mosaicism.
I’m particularly interested ...
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If DNA methylation inactivates genes, does DNA demethylation activate them?
DNA demethylation can be passive or active. The passive process takes place in the absence of methylation of newly synthesized DNA strands by DNMT1 during several replication rounds – for example, ...
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Archenteron vs Gastrocoele
What is Difference between “Archenteron” and “Gastrocoele”.
Are they same or different?
Gastrula is characterized by Archenteron or Gastrocoele or Both?
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Does natural selection select for randomness in development?
In a podcast with Sean Carroll and Liv Boeree they discuss a result from game theory that the optimal strategy in the face of incomplete information can require random decision making. For example, ...
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Why don't rates of cancer increase generation to generation?
As cells divide, they accumulate mutations that can sometimes cause cancer. Gametes have to divide like any other cell, and thus generation to generation mutations should accumulate in people's ...
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How can the same transcription factor be both an activator and suppressor of the same gene?
For example, hunchback in moderate concentrations is an activator of kruppel, but a suppressor of kruppel in large concentrations.
From what I've seen in literature, that's because the kruppel's ...
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Technical reason that specialized embryonic cells form
During the embryonic stage of human development, rapid cell division occurs and specialized cells form to build the various parts of the developing fetus.
I'm curious:
Why technically do specialized ...
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Is there a mechanism of timing or delaying the expression of gap genes?
Summary
Gap genes are expressed in presence of the right combination and amount of
transcription factors. But is there any additional mechanism of timing the expression of the gap genes to ensure ...
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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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How does axon guidance system precisely targets specific axons?
Axons find their way to the terminus by responding to axon guidance molecules (AGMs) that attract and repel growth cones or make them stir. This I understand.
Through a very specific combination of ...
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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, a baby starts to hear sounds at week 18. And according to How hearing works. Hearing involves
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Is there any example of genetic mechanism of delayed onset toxic effects?
We know that exposure to many toxic chemicals during embryonic development may show toxic effects later in life. It is called Developmental Origins of Health and Disease (DOHAD). Most of the ...
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How is the timing of gene expression controlled in developing embryo? [closed]
I understand how cell differentiation works in general (gradients of homeobox proteins etc), but how is timing controlled? Why do some genes switch on at a very specific moment of development and then ...
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How Does the Body Know a Finger is Fully developed? [closed]
When a baby is being developed inside the womb,
1) how does the baby's body know a finger, or any other part of the body, has been fully developed?
2) following question, how does it "stop" the ...