How do scientists measure the strength of an earthquake?

A few different scales measure how strong an earthquake is. The best known is the Richter scale, created in 1935, which uses an instrument called a seismograph to measure the size of the ground waves created by an earthquake.An earthquake’s size, or magnitude, generally ranges from 1 to 8 on the Richter scale (though the waves of some giant quakes have registered well beyond the top of the scale). The shock waves of an earthquake that registers a magnitude of 1 can only be detected with special instruments, while those with a magnitude of 8 cause massive damage.

Urea in our body

Urea is a waste product. It is found in our body and extracted from urine. However, it also plays a very important role in that it helps set up the countercurrent system in the nephrons. Urea is reabsorbed in the inner medullary collecting ducts of the nephrons, thus raising the osmolality in the medullary interstitial surrounding the thin ascending limb of the Loop of Henley. The greater the osmolarity of the medullary interstitium surrounding the thin ascending Loop of Henle, the more water will be reabsorbed out of the renal tubule back into the interstitium (and thus back into the body). 

Why are frozen foods less affected by bacteria?

Freezing in general causes cells to slow down everything. Cells work more slowly at lower temperatures. If you cool down to near-freezing, cells reproduce very slowly. At very lower temperatures the water in the cells will freeze. This can kill the cells or it slows down the oxygenation which degenerates food.

Why do we see light followed by sound in thunder storm?

When thunder and lightning occur in a thunderstorm, we first see the light followed by the sound. Normally sound travels in waves and we can hear the sound when these waves hit our ears. Similarly light also travels as waves.

Bones in our body

Babies are born with about 330 bones, but many of them join together during the process of growing up, creating fewer, larger bones. Adults have 206 bones. Some people end up with a few extra bones, though, in the arches of their feet or as an extra set of ribs in their rib cage.

What is a clone?

To understand cloning, we must first understand a few things about cells.  All living things, from the simplest to the most complex, are made up of cells. Cells are specialized to perform a variety of functions. There are muscle cells, skin cells, nerve cells, and so on.

What did dinosaurs eat?

Dinosaurs came in many different shapes and sizes, and they also had a variety of diets. Most dinosaurs ate plants, with the very large dinosaurs eating leaves from the tops of trees and smaller ones eating plants and bushes growing close to the ground.

Why do we have leap years?

Calendars are fairly fixed things. Each year has the same number of months and days, and the days follow a seven-day rotation going from Sunday to Saturday. But the movements of Earth do not conform exactly to the time designations humans have imposed.

Why are there 365 days in a year?

A long time ago (thousands of years, in some cases), when ancient societies recognized the need to record events and plan future happenings, calendars came into being. In colder climates, a calendar reflected the changing of the seasons and the movements of Earth around the Sun.

How can plants like seaweed grow underwater?

As long as they get enough sunlight to carry out photosynthesis, plants can live at various depths in oceans or other bodies of water. The stems of most underwater plants usually hold them upright so they can grow toward the light that filters down through their watery homes.

How can desert plants live without water?

No plant could live in a true desert, where it never rains. But the places where cacti and other desert plants grow do get rain only every couple of years or so. When it rains, desert plants quickly take up the water through their roots, storing it in fleshy leaves and stems. That stored water allows them to survive until the next rain comes.