In high school biology you learned that in humans, a normal cell contains 23 pairs of chromosomes; 22 autosomes, which are the same in both males and females, while in the 23rd, the sex chromosomes, females have two copies of the X chromosome while males have one X and one Y.

Their differences don't stop there. Chromosome pairs are numbered according to size, pair 1 being largest and 23 the smallest. And the Y is tiny compared to the X. X contains thousands of genes critical for life while the Y provides the instructions for initiating male development and making sperm.

Exactly how they work together during meiosis, the form of cell division that creates sperm and egg, contains a science mystery.

A 425-million-year-old Kampecaris obanensis millipede fossil is the world's oldest "bug." It is older than any known fossil of an insect, arachnid or other related creepy-crawly and it was found on the Scottish island of Kerrera.

It's about 75 million years younger than the age other scientists have estimated the oldest millipede to be using a technique known as molecular clock dating, which is based on DNA's mutation rate. Other research using fossil dating found that the oldest fossil of a land-dwelling, stemmed plant (also from Scotland) is 425 million years old and 75 million years younger than molecular clock estimates.

Two cities, Los Angeles and Indianapolis, reported higher than usual domestic violence incidents once COVID-19 stay-at-home restrictions were implemented in March.

For their paper, the scholars analyzed police calls for service before and during the coronavirus pandemic; from Jan. 2 to April 18 in Los Angeles and from Jan. 2 to April 21 in Indianapolis.School, restaurant and bar closures were ordered in both cities on March 16th. Los Angeles implemented government lockdown orders on March 20th and Indianapolis enacted similar orders on March 24th. 

A new study has found that even when it comes to something as broad as "wellness" such wellness programs have little recognizable impact on employee health, health beliefs, or medical utilization.

All things they were supposed to improve. 

The galaxy, named R5519, is 11 billion light-years from our Solar System and it is making stars at a rate 50 times greater than the Milky Way. The hole at its centre is truly massive, with a diameter two billion times longer than the distance between the Earth and the Sun.

That means it is three million times bigger than the diameter of the supermassive black hole in the galaxy Messier 87, which in 2019 became the first ever to be directly imaged.

Astronomers have captured an image of this "cosmic ring of fire" as it existed 11 billion years ago. It was roughly the mass of the Milky Way, is circular with a hole in the middle, rather like a titanic doughnut. 

There is a rare condition in humans and other vertebrates where they genetically belong to one sex but also have characteristics of the other.

Decades ago, scientists found that Oryzias latipes (Japanese rice fish, also called medaka) often undergo sex reversal in the wild and new exploratory research may lead to insight in humans.

In medaka fish. sex reversal involves genetically female larvae (meaning they have two X chromosomes) going on to develop male characteristics, or vice versa. Scientists had already discovered that environmental factors, such as temperature changes in the brackish and fresh waters where medaka fish live, are likely involved in their sex reversal.