The color of your eyes, skin, and hair is a product of cellular activity. In som
ID: 100300 • Letter: T
Question
The color of your eyes, skin, and hair is a product of cellular activity. In some animals, pigmentation is dynamic. Most people are familiar with scenes of an octopus blending in with its environment or chameleons turning bright red to ward off threats. Although less dynamic, human skin color can also changeor tanwhen exposed to sunlight. How do cells pull off this remarkable feat?
The distribution of melanosomes in cells is tightly regulated in animals that rapidly change color. Dark-colored cells have melanosomes scattered throughout the cytoplasm while light-colored cells have them aggregated near the nucleus. How could cells use microtubules and motor proteins to change the distribution of melanosomes?
Microtubules originate near the nucleus of animal cells, and the positive ends project outward.
Kinesin would be responsible for moving melanosomes outward to generate dark-colored cells.
The melanosomes move along microtubule tracks using motor proteins.
Dynein would be responsible for moving melanosomes outward to generate dark-colored cells.
Kinesin would be used for moving melanosomes back to the nucleus in light-colored cells.
Dynein would be used for moving melanosomes back to the nucleus in light-colored cells.
Microtubules originate near the cell wall of animal cells, and the positive ends project outward.
Which of these is the correct answer?
Explanation / Answer
1.Ans-
Animals such as squid, cuttlefish, octopuses, frogs, lizards and fish can change their color. with the help of ectoderms. Colouration in animals is produced by cells and tissue with the help of chemical pigments that present in the skin called chromatophores. Chromatophores are pigment present in ectotherms and responsible for producing different skin and eye color.
Colour change is occurred by movement of melanin pigment in melanosomes within the melanophores. The skin color becomes very pale when melanin pigment assembled together within the center of the cell and become dark when they move from the arms of the melanophores towards the skin’s surface.
2.Ans-
Microtubules originate near the nucleus of animal cells, and the positive ends project outward.
Kinesin would be responsible for moving melanosomes outward to generate dark-colored cells.
The melanosomes move along microtubule tracks using motor proteins.
Dynein would be used for moving melanosomes back to the nucleus in light-colored cells.
The microtubule originates near the nucleus of the cell and the plus ends projected outwards and minus ends are nucleated by the centrosome.
The motor protein dynein is used for concentrating the melanosomes in the center of the cell and concentrating melanosomes towards the center cause the skin cell become very pale to appear lighter color.
The protein kinesin is involved for dispersing the melanosomes to outward of the cell and dispersing melanosomes to the periphery causes the cell become darker.