Are intergenic sequences and introns considered genes?

The better question is: Are there genes within intergenic sequences or introns?

And the answer depends on whether you use a modern definition of “gene” or the traditional one.

The traditional definition is a gene is a sequence of DNA that codes for a protein or polypeptide, with mRNA as the intermediary. And that’s still a pretty solid definition for prokaryotic genes.

Now that we know a lot more about how a eukaryotic organism’s genome functions, the definition of a gene has necessarily expanded. A common definition in molecular biology is that a gene is DNA sequence that codes for something functional.

Something functional certainly includes polypeptides and proteins, but also includes DNA sequences, which function as an “enhancers” or “silencers” of expression. Many of these are found within intronic and/or intergenic sequences. They can even be kilo-bases distant from the gene being regulated.

The definition should also includes DNA which is transcribed to regulatory RNA such as siRNAs & lncRNAs, which are not translated, either.
There are also numerous segments of DNA transcribed to RNA, which folds into complex and rather ornate structures, we know little about except they probably serve some vital function in the cell, and almost certainly errors in these may play role in disease. Here is a schematic of ITS-1 RNA coded for by rDNA:

I refer you to the extremely knowledgeable Adriana Heguy’s response to a similar question: What is a gene in modern biology?

If memory serves, the human genome contains ~17,500 polypeptide-coding genes, and about ~6,000 (known) genes that function is some other essential manner within the cell.

I expect we discover very few “new” protein-coding genes in humans because we already “know what to look for,” but will discover many more of the “other” varieties of genes over the next decade, or so. And yes, some of these are bound to turn up in intergenic regions, intronic sequences and maybe buried within the many thousands of pseudogenes our genomes are rife with.

Finally, to confuse the matter further, there are functional DNA/RNA hybrid species which have functional roles in cells. Four billion years of evolving life has generated all sorts of novel cellular machinery for us to sort out, but we’re getting there! Consider it took from 1990 to 2003 in giant labs to sequence the first human genome, at a cost of ~3 billion USD. Today it can be done on a bench in ONE DAY, and scientists are aiming for a cost of ~$1,000 USD, representing a cost reduction of over 6 orders of magnitude!

Images from: https://www.researchgate.net/figure/232718156_fig3_ITS1-rDNA-Folding-Structures-a-Predicted-RNA-folding-structure-of-ITS1-in-T-rotula

 

What triggers phosphorylation and dephosphorylation in Na-K ATPase pump?

• Phosphorylation is a widely used post-translational modification method of protein or enzyme activity.
• The sodium-potassium pump is an example of an active transport membrane protein/transmembrane ATPase.
• Using the energy from ATP, the sodium-potassium moves three sodium ions out of the cell and brings two potassium ions into the cell.

The above figure is the X-ray crystallography structure of the pump. And the yellow spots represent the amino acids that are phosphorylated and dephosphorylated during the process.

The above picture shows the amino acids of the pump phosphorylated and phosphorylated during the process.

STEPS OF WORKING OF Na+-K+ pump:

1. The sodium-potassium pump binds ATP and three intracellular Na+ ions.
2. ATP is hydrolyzed resulting in adenosine diphosphate (ADP) and inorganic phosphate. The free phosphate phosphorylates the sodium-potassium pump.
3. A conformational change in the pump exposes the Na+ ions to the outside. The phosphorylated form of the pump has a low affinity for Na+ ions, so they are released.
4. The pump binds two extracellular K+ ions. This causes the dephosphorylation of the pump, reverting it to its previous conformational state, transporting the K+ ions into the cell.
5. The unphosphorylated form of the pump has a higher affinity for Na+ ions than K+ ions, so the two bound K+ ions are released.
6. ATP binds, and the process starts again.

QUEST YOUR THIRST FOR KNOWLEDGE.

 Can someone send the classification of kingdom plantae?

 

Which animals could survive car crashes that would be fatal to humans?

This.

A group of Australians built a model of what it would be like if humans were somehow designed to survive car crashes. Obviously, this is a ridiculous model, but designed from the ground up.

The brain has more ligaments to help sustain itself during an impact. The legs are actually digitgrade rather than plantigrade, so he would be actually walking on his toes like cats and dogs. These allow him to jump out of the way in a spring-loaded fashion. The ribcage is also extraordinarily thick, acting as an airbag to cushion the chest should he suddenly lurch forward if he was not wearing seatbelt.

While a person like this would never actually exist in nature, it’s still an interesting concept when it comes to bioengineering things to be safer.

 

What would decrease genetic variation in a population? What are some examples?

A population bottleneck decreases genetic variation in a species or subspecies. A founder effect is similar. The Cheetah is an example. All cheetahs share a small number of alleles. They have less than 1% genetic variation. They are almost like twins. They had two bottlenecks, one about 10,000 years ago and again in the last 100 years.Dating the genetic bottleneck of the African cheetah. Humans are another example. Elephant seals were hunted to 20 individuals in 1890. There is no variation in 24 genes.. There are 30,000 today. California Condors. Pandas. Inbreeding of dog or cat breeds does this too.

 

Why don't humans stretch instinctively like cats?

Fun fact, there is a name for the kind of stretching you see your cat or dog doing, it’s called pandiculation.

Here’s a cat pandiculating:

A lion:

A dog:

A horse:

An elephant:

A human:

Yeah, that’s right. Turns out the premise behind your question is kind of flawed because humans, and pretty much every mammal for that matter, share the same instincts to stretch as our cats. Pandiculation is actually a key function of our musculoskeletal system as it is a subconscious action that prepares our muscles for movement after long periods of rest.

EDIT: Because it’s come up a couple of times in the comments, here’s some PANDAculation for you all too.

…heh, see what I did there?

 5 warning signs of Uterine Cancer

Uterine cancer, like other cancers, does not show symptoms clearly in its early stages, which is the lower part of the uterus connected to the vagina, and the main cause of uterine cancer is a virus called “papillomavirus”. When exposed to an HPV infection, the body’s immune system prevents the virus from causing harm. Despite this, the virus remains alive for years in a small percentage of people and is involved in transforming some cervical cells into cancerous cells. Therefore, regular examinations of the uterus should be performed. However, he indicated that there are signs that warrant caution and that should never be ignored because they indicate the possibility of developing this type of cancer, especially if any of these warning signs appear, which we will mention in the article.

Warning signs of uterine cancer

1- Vaginal bleeding :

Vaginal bleeding is one of the most common signs of uterine cancer, and bleeding can appear after sexual intercourse or between menstruation and beyond, as well as bleeding during the arrival of menopause.

2- Changes in urination and excretion :

Feeling the need to urinate more often than usual, or having changes in bowel habits. As well as feeling severe pain when urinating and when practicing intimacy.

3- Lethargy and fatigue :

Feeling lethargic and tired for no apparent reason may be due to uterine cancer, especially if it accompanies the rest of the previous symptoms.

4- Pelvic pain :

It may range from minor to severe pain, and may involve the entire pelvic area or a specific spot. Sometimes this pain appears during sex or urination, and other times without an apparent reason.

5- Unusual vaginal secretions :

If you notice a dark, foul-smelling discharge that may have a tendency to runny nose, see your doctor. There are many reasons that may cause the secretions to appear different than usual, so do not panic, but consult your doctor in all cases.

Note:

if the disease is detected in its early stages; The possibility of recovery from it is great, and the patient may also have the ability to conceive and give birth after completing the treatment if it is detected at a very early stage, but treatment in its later stages mostly depends on the eradication of cancer cells, and this results in the inability to conceive. distance.

 

Scientists consider glycolysis to be one of the earliest biochemical processes to evolve in the first living cell. What are the evidences that support this?

Some theorists have proposed that the earliest living things used reactions that resemble those modern organisms use to ferment sugar, glycolysis.[1] Yeast use a version of that reaction to get energy by turning glucose into alcohol.[2]

This makes sense because there wasn’t much oxygen in the early Earth and glycolysis doesn’t require oxygen. Some or maybe all of the chemical reactions involved can happen without biological enzymes. Heating a mixture of water, sugar, and minerals may be enough.[3]

But there might not have been enough sugar in the primordial soup to make this an important source of energy.

Some scientists have tried to reconstruct the biochemical reactions the earliest organisms used by looking at chemical reactions that are widely used in modern organisms and making guesses about the environment in which early organisms might have lived.

Here’s one reconstruction. In this scenario, a set of reactions called the Wood–Ljungdahl pathway use hydrogen as an electron donor and carbon dioxide as an electron acceptor. Hydrogen, CO2, and H2S could have provided the nutrients and some of the energy needed to power life. This model assumes that life arose at an undersea hydrothermal vent having an alkaline interior and surrounded by mildly acid water. That difference could have provided energy to make ATP[4]

You can learn more from these publications:

The physiology and habitat of the last universal common ancestor.

https://www.molevol.hhu.de/fileadmin/redaktion/Fakultaeten/Mathematisch-Naturwissenschaftliche_Fakultaet/Biologie/Institute/Molekulare_Evolution/Dokumente/Weiss_et_al_Nat_Microbiol_2016.pdf

The last universal common ancestor between ancient Earth chemistry and the onset of genetics

https://www.researchgate.net/publication/327065850_The_last_universal_common_ancestor_between_ancient_Earth_chemistry_and_the_onset_of_genetics/fulltext/5b761c7492851ca65064e77d/The-last-universal-common-ancestor-between-ancient-Earth-chemistry-and-the-onset-of-genetics.pdf?origin=publication_detail

Footnotes

[1] The Origin and Evolution of Cells

[2] Glycolysis | Introduction, Pathway , Diagram & Summary

[3] Non‐enzymatic glycolysis and pentose phosphate pathway‐like reactions in a plausible Archean ocean

[4] https://www.molevol.hhu.de/fileadmin/redaktion/Fakultaeten/Mathematisch-Naturwissenschaftliche_Fakultaet/Biologie/Institute/Molekulare_Evolution/Dokumente/Weiss_et_al_Nat_Microbiol_2016.pdf

 

You know the cell that multiplied to form you, so how does it split itself apart to form so many varieties of cells, won't it be the same cell every time it multiplies?

In early embryonic development—a morula like this—the cells are more or less genetically identical.

As cells proliferate, segregate into different functional groups, and form the first tissue layers (ectoderm, mesoderm, endoderm), and then those tissue layers differentiate into separate organs, some genes are silenced and others are activated (expressed). Even though different cells have the same genes, each cell type uses only some of them and silences others, leading to the variety of cells, tissues, and organs in the developed body.