DECODING DNA

Which parent did you get most DNA from? 10 amazing facts about our genes

Image: Sangharsh Lohakare

Genetics can both fascinate and befuddle us with its complexity, but understanding its mechanisms just might be the key to deciphering the building blocks of our entire existence. From genes that are shared between different species to viruses that insert themselves into our DNA, here are 10 things you—likely—didn’t know about genetics and DNA.

Image: Ganapathy Kumar

We vastly underestimate the amount of DNA we carry around in our cells. If you were to unravel all the DNA molecules in your body and lay them end to end, they would stretch an astonishing 10 billion miles—enough to reach the moon and back over 40 thousand times! However, despite the vast amount of DNA in our bodies, if we were to gather and weigh all of it together, it would surprisingly amount to only around 8 ounces.

Image: Harshad Khandare

Surprisingly, humans share about 50% of their DNA with bananas! But this shouldn’t be too surprising given the fact that all life on Earth evolved from a single organism, roughly 3.5 billion years ago. Every living creature on our planet has the same type of DNA, undergoing almost identical processes in order to live and reproduce.

Image: Pedro Lastra

Certain species, like salamanders and starfish, possess remarkable regenerative abilities, allowing them to regrow lost limbs. Other species like axolotls or jellyfish can even go further, regenerating anything from parts of their brains to crucial internal organs, or even recovering from being cut in half! Understanding the genetic mechanisms behind this ability holds promise for regenerative medicine and even tissue engineering.

Image: Hillshire Farm

Surprisingly, we inherit slightly more DNA from our mother’s side. While everyone receives 50% of DNA from each parent, a small portion of mitochondrial DNA, which is passed down exclusively from mother to child, contributes to this imbalance. Mitochondrial DNA also allows for tracing the ancient relationships of human populations, and for this reason, it is extensively studied in anthropology and evolutionary biology.

Image: Pietro Jeng

Scientists have already successfully stored digital data within DNA molecules, and many believe the technique has potential as a long-term storage solution. Its vast storage capacity and durability make it very attractive to store digital information, but the technology is still in development.

Image: George Prentzas

DNA is sort of a blueprint that determines most of our traits and characteristics, but it is far from having the last say on how particular traits or genes will express themselves. Environmental factors can modify gene expression without changing the underlying DNA sequence, potentially impacting health and development. This is the reason that even identical twins have noticeable differences, like unique fingerprints.

Image: Transly Translation Agency

Studies have shown that certain environmental factors experienced by parents, like exposure to stress or traumatic events, can leave chemical marks on DNA that are passed down to offspring. This phenomenon is called transgenerational epigenetic inheritance, and though it seems to contradict some of the tenets of Darwinian ideas, it is now widely accepted as one of the many mechanisms of genetic inheritance in most living organisms.

Image: Fusion Medical Animation

Rare genetic mutations can give natural immunity to certain diseases. In time, if these genes can be distributed sufficiently within a given population this can even lead to collective immunity. For example, there is a genetic mutation called CCR5-delta 32 that provides natural immunity to the Human Immunodeficiency Virus (HIV) by altering the structure of a specific protein these viruses use to infect cells. Studying these unique phenomena can be promising for developing cures and more effective treatments.

Image: Sangharsh Lohakare

A significant portion of the human genome consists of non-coding DNA, often referred to as "junk" DNA because it does not code for proteins. However, recent research suggests that this non-coding DNA plays important roles in gene regulation and genome stability, challenging the notion of it being just 'junk'.

Image: Belinda Fewings

Horizontal gene transfer is a very weird phenomenon where genetic material is transferred between completely different species, bypassing traditional vertical inheritance from parent to offspring. Although the mechanism behind this process is poorly understood, scientists believe that it played a significant role in the evolution of many organisms. In fact, certain types of viruses force this to happen in order to encode themselves into the DNA of their hosts and reproduce.

People remember stories

Your knuckles know more than you think: Here’s what they can tell you

You might forget where you left your keys or your glasses, but some things are forever imprinted in your memory one way or another. And for those things you simply can’t seem to remember, some useful mnemonic devices can help you. For example, how can you remember the presidents on our bills? And what about all the spelling rules our language has? Is it "gray" or "grey"? Don’t worry, we’ve got you covered. Keep reading and learn a few tricks.

You may handle bills every single day, but can you answer whose face is on each one? You don’t need to remember; this mnemonic device will do it for you: The phrase "When Jeff Left Home, Jack Got Fat" gives you the answer. As you can notice, the first letter of each word stands for the last name of the president or founding father: Washington, Jefferson, Lincoln, Hamilton, Jackson, Grant, and Franklin.

Yes, we keep lots of calendars, but sometimes we have to double-check if a month has 30 or 31 days. Has this happened to you? If it has, next time you’ll want to use your knuckles. The rule is simple: Make two fists and count across your knuckles and the dips between them. Months that land on knuckles have 31 days. The dips are the shorter months, February being the shortest, naturally.

Have you ever had to try a few times before knowing whether you were loosening or tightening that screw? Well, with this rhythmic phrase, you won’t need to do that anymore. If you turn right, you’ll be making it tight. On the other hand, if you turn left, you’ll loosen it.

English spelling keeps everyone on their toes, and certain words have regional rules that make everything worse. Nobody can remember them all, so this device comes in handy. When you don’t know whether it is "gray" or "grey," think of it this way: Gray, with an A as in America. Grey, with an E, as in England.

"Necessary": This is another word with a spelling that can create a few problems. And the mnemonic device for this one is picturing a T-shirt. You know how a T-shirt has one "Collar" (that’s one C) and two Sleeves (that’s two S)? That’s it, spelling solved.

Back in school, memorizing the Great Lakes could feel like a geography pop quiz. Simply the word "HOMES" is a trick that many teachers share with their students. Why HOMES? Because each letter represents a lake: Huron, Ontario, Michigan, Erie, and of course, Superior.

Just as with any other long list, remembering the order of the planets in our solar system is no piece of cake. But this fun phrase has the answer to your prayers, it’s not bout nachos, but about the names of the planets in order: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.

This one sounds like breakfast advice, but it’s actually a compass lesson. The first letters match the four cardinal directions in clockwise order: North, East, South, West. Many kids learned this one in school, and plenty of adults still repeat it quietly when trying to picture a map in their heads.

This may sound silly, but many people struggle to point left; most need more than just a second to figure out which one is actually left. But many have discovered something quite useful: hold up both your hands and use your thumb and index finger to do an "L." Can you see which one forms a clear letter? That’s left, of course.

Is this connected to the Constitution? Yes, it is. Civics teachers sometimes lean on this unusual sentence to remember the seven articles of the US Constitution. Each word stands for one: Legislative, Executive, Judicial, States, Amendment, Supremacy, and Ratification. Now you just have to remember this funny phrase.