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Sharpen Your General Knowledge
Shamim Ansary:
Why Does an Octopus Change Color?
Even though octopuses belong to a group of shellfish called mollusks, they have no outside shell. A tough skin, called a mantle, covers the octopus’ body. This mantle contains small bags of pigment, or coloring matter, which are connected to the animal’s nervous system.
Any outside stimulus that excites the octopus makes its skin change color. It can change to blue, purple, brown, red, gray, white, and sometimes even striped.
Shamim Ansary:
What Is the Carbon Cycle and What Percentage of Organisms Are Made of Carbon?
To survive, every organism must have access to carbon atoms.
Carbon makes up about 49 percent of the dry weight of organisms.
The carbon cycle includes movement of carbon from the gaseous phase (carbon dioxide in the atmosphere) to solid phase (carbon-containing compounds in living organisms) and then back to the atmosphere via decomposers.
The atmosphere is the largest reservoir of carbon, containing 32 percent CO2.
Biological processes on land shuttle carbon between atmospheric and terrestrial compartments, with photosynthesis removing CO2 from the atmosphere and cell respiration returning CO2 to the atmosphere.
Shamim Ansary:
What Causes Grey Hair and How Does the Lack of Melanin Make My Hair Look White?
As people age, their bodies stop producing melanin, the pigment that colors hair.
Without melanin, hair becomes transparent, so you can see through to the air inside the hollow hair shafts.
The diffusion of the light through the air bubbles makes hair look white.
Hair dye works to hide the white because it stains the outside of the hair shaft.
Shamim Ansary:
Why Does Hair Turn Gray When We Get Old and How Long Does It Take for Our Hair to Turn Gray as We Age?
Gray, or white, is merely the base color of our hair.
Pigment cells located at the base of each hair follicle produce the natural dominant color of our youth.
However, as a person grows older and reaches middle age, more and more of these pigment cells die and color is lost from individual hairs.
The result is that a person’s hair gradually begins to show more and more gray.
The whole process may take between 10 and 20 years, rarely does a person’s entire collection of individual hairs, which, depending on hair loss, can number in the hundreds of thousands, go gray overnight.
Interestingly, the color-enhancing cells often speed up pigment production as we age, so hair sometimes darkens temporarily before the pigment cells die.
Shamim Ansary:
Why Do Some People Have Straight Hair and Others Have Curly Hair?
Every hair on your head or on your body is made up of a root, the soft, bulb-shaped section under your skin, and the shaft, the longer strand that sticks out of your skin.
If you were to cut a shaft of your hair from near the root and look at a cross-section of it under a microscope, it would have either of two shapes: round or flat. If it appears round, that means your hair will grow out straight; if that cross-section appears flat, that means your hair will grow at different rates in different places, making it curl or wave. The flatter the shaft, the curlier it will be. The shape of your hair shafts is determined by the shape of your parents’ hair shafts, for this is one of the characteristics you inherited from them.
Some people with curly hair are unhappy with it and have their hair straightened, while others with straight hair take “permanent waves†to make their hair curly. But both of these changes are only temporary, lasting only a short time, for the shape of the shaft cannot be changed, and as that person’s hair grows out, it will look the same as before the change.
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