Biology

How fast do fingernails grow?

In adults, they grow about 0.02 inches a week, or about 0.9 inches per year. For some it may seem like they grow much faster than that, and for some they probably do. Fingernails and toenails grow faster in younger people than in older. Read more…

How long does it take food to digest?

As the average person’s stomach will hold less than two quarts, it only stays in this stage of the digestive process for three to five hours. The stomach slowly releases this semi-digested food to the intestines where it completes the digestive process. Roughly 15-17 hours after you take the first bite, the food is excreted as feces.

Some foods may pass quicker than this, depending on one’s specific reaction to a specific food. And some foods may stay in your system longer. Other variables affecting digestion time is one’s level of physical activity and even drugs taken subsequently (caffeine, nicotine, prescription drugs, etc.).

Posted by admin for best selling toys at Atomic Elephant Science and Toy Co. 

How does squinting improve vision?

Under normal conditions, light comes into the eye in all directions. Rays coming in at an angle above or below the horizontal will naturally focus in front of or behind the center of vision. Rays coming in more directly would tend to focus more directly on the retina. By squinting, you create a smaller opening for incoming light – similar to how the aperture on a camera works. The narrower you can make this “aperture,” the more likely the light rays coming in will be closer to the horizontal Read more…

Why do all newborn babies have blue eyes?

At birth, the genes that make the pigment protein are not being read by the cell (they are turned off). Almost all babies have blue eyes because the iris has not yet made brown pigment (called melanin) that colors the iris.

As the child’s eyes are exposed to light (as they weren’t in the womb), the light then triggers the cell to start reading the gene. But it can take a while for the cell to ramp up to the final levels of pigment. That is why so many babies have blue eyes for their first months of life. Usually by their first birthday a baby’s eye color has settled in, but sometimes the iris doesn’t make enough melanin until about 3 years of age.

A nice description from About.com follows: “An infant’s eye color is determined by a substance called melanin. Melanin is a dark pigment contained in the iris, the structure that controls how much light is allowed into the eye. The color of the iris is determined by the amount of melanin in the iris. Light eyes have very little pigment, whereas darker eyes have a lot. In newborns, the pigmentation process of the iris is not yet complete. Babies with darker skin are usually born with dark eyes that stay relatively dark. Iris color in lighter-skinned babies is usually a blue or bluish-gray color at birth, then change as they grow. Melanin production changes during the first year of life, usually resulting in a darker, deeper eye color.”

Sources: Understanding Genetics at TheTech.org.

Bubonic Plague

What causes the Bubonic Plague and how deadly is it?

The Bubonic plague is a disease of the lymphatic system caused from the bite of an infected flea. The fleas are often found on rodents and seek live hosts (such as humans) when their rodent hosts die. Once established, bacteria rapidly spread to the lymph nodes and multiply. Yersinia pestis can resist phagocytosis and even reproduce inside phagocytes and kill them. As the disease progresses, the lymph nodes can hemorrhage and become necrotic. Bubonic plague can progress to lethal septicemic plague in some cases. Bubonic Plague kills about 50% of infected patients within one week.

What most people reading this were probably searching for is actually the Black Death, a specific incident of a Bubonic Plague epidemic that happened in Europe in the 1340s. At the time of the breakout, the world’s population is estimated to have been about 450 million. The Black Death killed about 75 million, or roughly one sixth of the population on Earth. Compare those figures to today’s population and that would be the equivalent of over 1 Billion people dying from the breakout.

The name “Black Death” comes from the fact that the disease causes symptoms like spots on the skin that are red at first and then turn black. Other symptoms include heavy breathing, continuous blood vomiting, aching limbs and terrible pain. The pain is usually caused by the actual decaying, or decomposing of the skin while the infected person is still alive.

Why do nine-banded armadillos always have four offspring of the same gender?

The Dasypus novemcinctus, or nine-banded armadillo female almost always gives birth to four young of the same sex. The offspring are actually quadruplets that come from one fertilized egg splitting into four parts.

The general wikipedia description follows: the Nine-banded Long-nosed Armadillo or just Nine-banded Armadillo, (also known as the poor man’s pig or poverty pig), is a species of armadillo from North, Central and South America. It is the most widespread member of the group. Its ancestors evolved in South America, but were able to invade North America during the Great American Interchange after the Isthmus of Panama formed 3 million years ago.

The Nine-banded Long-nosed Armadillo is a solitary, mainly nocturnal animal, found in many kinds of habitats, from mature and secondary rainforests to grassland and dry scrub. It is an insectivorous animal, feeding chiefly on ants, termites and other small invertebrates. This species is the only known animal that is able to inflate its own intestine in order to float across a river. It can also hold its breath for up to 6 minutes in order to walk across the bottom of narrow rivers. Additionally, the nine-banded armadillo always produces four identical offspring. The armadillo can jump three to four feet (90-120 cm) straight in the air if sufficiently frightened, making it a particular danger on roads.

What is a pregnant goldfish called?

This is a bit of a humorous post as this question has made the rounds on the Internet for the last several years. The short answer is: goldfish are egg-layers and as such, they’re never considered pregnant. A female goldfish carrying eggs is said to be “ripe” but no ichthyologist would say she’s pregnant. You may have stumbled upon posts or trivia lists saying that a pregnant goldfish is called a twit, twat, twerp or whatever. They’re not.