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  • It's AumSum Time

  • Hi guys.

  • Can you guess the title of my next video?

  • Hurry up.

  • Write your guess in the comments section below.

  • Is radiation harmful?

  • Yes dude.

  • It is very very harmful.

  • No.

  • Not every radiation is harmful.

  • Radiation is basically energy traveling as waves or particles.

  • It can be classified as ionizing and non-ionizing radiation.

  • Non-ionizing radiation includes visible light, infrared rays, microwaves, radio waves, etc.

  • Non-ionizing radiation is generally not harmful.

  • Now, ionizing radiation includes gamma rays, X-rays.

  • Radiation given off by radioactive elements, nuclear power plants, nuclear weapons, etc.

  • Although we are daily exposed to low levels of ionizing radiation, it doesn't cause any harm.

  • However.

  • Exposure to high levels of ionizing radiation in a short period of time can damage the DNA in our cells.

  • Causing cell dysfunction or even cell death.

  • Also, sometimes when the damaged DNA tries to repair itself.

  • There can be a change or mutation in the genes, leading to uncontrolled cell division.

  • Thus, causing cancer.

  • High levels of ionizing radiation can even turn water in our body into hydrogen peroxide which is really toxic.

  • Thus, the ionizing radiation can prove to be very harmful.

  • Can jellyfish live forever?

  • To understand this, let us observe the lifecycle of a jellyfish.

  • A fertilized egg of a jellyfish forms planula.

  • Planula then attaches itself to a hard surface like a rock or sea floor.

  • Then, it transforms into a polyp.

  • Then through a process called budding, tiny jellyfishes emerge from the polyp.

  • Some jellyfishes may live for a few hours.

  • Some may live for a few months while some may live for several years.

  • However.

  • A type of jellyfish known as Turritopsis dohrnii.

  • Which is also called the immortal jellyfish is said to live forever.

  • Stop bluffing.

  • How's that possible?

  • When the immortal jellyfish is injured, stressed or cannot find enough food, it reverses its lifecycle.

  • It transforms into a blob-like structure called cyst which then transforms into a polyp.

  • Then again through budding, tiny jellyfishes emerge from the polyp.

  • Thus making Turritopsis dohrnii immortal.

  • How do fish breathe underwater?

  • With the help of oxygen cylinders and masks.

  • No.

  • Fish breathe underwater using the oxygen that is dissolved in water.

  • So, do they use a mini vacuum cleaner to absorb oxygen from water?

  • No.

  • To absorb oxygen from water, fish use special organs called gills.

  • Gills are full of blood vessels.

  • Also, the walls of the gills and blood vessels are very thin.

  • Now, during breathing, fish take in water through their mouth and forcefully push it through their gills.

  • When the water moves through the gills.

  • The dissolved oxygen from the water passes through the thin walls of gills.

  • Blood vessels, and enters the blood.

  • Apart from this, the waste carbon dioxide present in the blood passes into the water.

  • Thus helping fish to breathe underwater.

  • Eventually, the carbon dioxide-rich water is given out from gills.

  • Topic: Pathogens.

  • Why do we get fever?

  • So that we can take a holiday from work.

  • No.

  • Fever is a protective response of our body to fight against pathogens.

  • Such as bacteria, viruses and fungi.

  • These pathogens cause diseases.

  • Hence, when pathogens enter our body.

  • The immune cells such as white blood cells produce chemicals called pyrogens.

  • Which are released into the bloodstream.

  • I thought like movies, they are released in theaters.

  • Please, pay attention.

  • Hypothalamus, which is a small part of our brain, regulates our body temperature.

  • However, when these pyrogens reach the hypothalamus.

  • It starts to raise our body temperature, thus producing fever.

  • Now,

  • One of the reasons for producing this fever is that many pathogens cannot survive at high temperatures.

  • Thus, they die and we remain safe.

  • Why do leaves change color and fall?

  • Leaves contain various colored pigments like orange, yellow, green, etc.

  • But among all these pigments.

  • Only green colored pigment called chlorophyll traps sunlight and helps leaves prepare food.

  • Now, since green colored chlorophyll has such an important function.

  • The amount of chlorophyll is much higher in leaves, causing them to usually appear green.

  • No, they're black.

  • Oops, I'm wearing sunglasses.

  • Now during autumn or fall, there is not enough sunlight for chlorophyll to trap.

  • As a result, leaves are not able to prepare much food.

  • Hence, the plant begins to shed its leaves instead of wasting energy on their maintenance.

  • However.

  • Before shedding, the plant absorbs required nutrients from the leaves and breaks down chlorophyll.

  • Now, since chlorophyll is broken down, other pigments in leaves become visible.

  • Resulting in the change of color.

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B2 中高級 美國腔

輻射有害嗎?| 輻射對人體有害嗎? (Is Radiation Harmful? | #aumsum)

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    AumSum 發佈於 2021 年 01 月 14 日
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