Iris muscles In the iris, the ‘Iris sphincter muscle’ constricts the pupil, and the ‘Iris dilator muscle’ enlarges the pupil. Both muscles work in reverse, controlling the size of the pupil. Ciliary body connected to the lens The lens of … more
Pulse Blood vessels are elastic. When the heart contracts, the blood vessels dilate; when the heart relaxes, the vessels constrict. Hemoglobin in the blood absorbs particular light. Therefore, when light is applied to human tissue, the passage of light varies … more
Find the task sequence to amplify DNA. PCR (Polymerase Chain Reaction) PCR is a method for repeatedly amplifying a specific gene sequence from a small DNA sample. PCR goes through three basic steps. DNA denaturation Heat to about 90°C to … more
Flagellate Hundreds of millions of years ago, light-sensing organelles arose inside the monad. Creatures with ‘photoreceptors’ are able to distinguish day and night and can also avoid harmful ultraviolet light. Flatworm And these photoreceptors have evolved into light-sensing cells of … more
Focusing The light started from the object must have arrived exactly at one point on the retina to see things in detail. On the other hand, if the light from one point of the object is scattered all over the … more
Plants Respiration Animals carry out active breathing movements to obtain the energy they need for life activities. Through this breathing movement, oxygen is absorbed, and carbon dioxide is released. Like animals, plants do respiration. However, plant respiration is performed through … more
Cell division Multicellular organisms like humans are made up of cells of varying shapes and functions. Most cells are so small that they can see them only under a microscope because once they reach a certain size, they no longer … more
Respiratory organ To maintain life, we absorb oxygen from the air. And we export carbon dioxide from the body. Human respiratory organs include the nose, organs, bronchi and lungs. Each bronchus in the lung continues to diverge and taper. The … more
This simulation assumes that the loading dye is 50bp and the marker is 50bp. (‘bp’ is a unit showing the number of base pairs of DNA.) Electrophoresis Electrophoresis is a chemical phenomenon in which an electric charge in a solution … more
The sensing part is slightly different depending on the frequency of sound. Move the slide bar to check. Cochlear Inside our ears, there is a sensory organ that senses sound. The overall shape resembles a snail called ‘cochlear.’ The cochlea … more
Chromosome If you look at the onion root under a microscope, you can see cells of different shapes and sizes, such as cells with an apparent nucleus, cells that appear to be split into two cells, and cells that have … more
