字幕表 動画を再生する 英語字幕をプリント 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.