It's AumSum Time. Why don't sharks have bones? Sharks belong to a special class of animals
called Chondrichthyes. The skeleton of these animals is not made
of bones, instead it is made of cartilage. What? Cartilage is the same stuff that our ears
and nose are made up of. And it is due to this material that sharks
are able to skilfully maneuver in water. But how? Wait. I will explain. Cartilage is less dense than bones. Hence, it is much lighter, making sharks weigh
less. And thus, helping them stay afloat. Also, as the cartilage is flexible. It gives shark the ability to swim quickly,
catch its prey as well as conserve energy. Besides this, studies have shown that. The skeleton made of cartilage heals faster
than that made of bones. So, sharks are boneless. Why don't we drink seawater? Simple. Because it tastes salty. You are right. But besides taste. We don't drink seawater because it contains
extreme amount of salt. Which can have dangerous effects on our body. Really. Indeed. Now, normally in our body. The amount of water and salt, inside and outside
our cells is the same. However, if we drink seawater, the amount
of salt outside our cells will increase. Making the outside region much more concentrated. Hence, to dilute the outside region and maintain
balance, inside and outside the cells. The water present inside the cells starts
flowing outside, causing our cells to shrink. This can really have dangerous consequences,
right? Absolutely. Moreover, to remove the extreme amount of
salt, our kidneys will produce more urine. Making us urinate more water and thus, causing
severe dehydration. Why is blood red in color? Because everyday it bathes using red paint. No. Our blood mainly consists of. A liquid called plasma, red blood cells, white
blood cells and platelets. However, the color of our blood is basically
because of red blood cells. Each of the red blood cells contains hemoglobin. Hemoglobin is an iron rich protein. When hemoglobin binds with oxygen. The interaction between them gives our blood
its red color. Moreover, like human beings, not all animals
have red color blood. This is because the blood of some animals. Such as octopuses, spiders, etc. has hemocyanin
instead of hemoglobin. Hemocyanin is a copper containing protein. When hemocyanin binds with oxygen, their interaction
gives the blood a blue color. The blood of some lizards has biliverdin instead
of hemoglobin. Which give their blood a green color. Why do we bite our nails? To save our expenses on manicure. No. Nail biting or onychophagia is a bad habit. And there is no specific reason why people
do it. I will find the reason in only 2 seconds. Don't bother. A habit forms due to three things, a trigger,
action and reward. So, in case of nail biting. A research suggests that a broken nail which
is hurting can be a trigger. Biting and removing it is the action. When the broken nail is taken off, the pain
is reduced and we feel better. This is our reward. Now, if we again encounter similar triggers
like a broken nail. We repeat the same action to get the reward. Which gradually causes onychophagia, i.e.,
we get a habit of nail biting.
