The Moon is thought to have come from the Earth. In 1975, the giant impact hypothesis was put forward. This suggests that the Earth was hit by a planet about the size of Mars around the time of the formation of the solar system approximately 4.5 billion years ago, and the impact caused part of the outer layer of the Earth to spin off and form what is now the Moon.
The answer is; producing a unique antibody from all other B cells by genomic rearrangement.
An isolated B cell produces monoclonal antibodies (also called Immunoglobulins). Different B cell types produce different types of antibodies (hence the serum of an animal has polyclonal antibodies). Memory B cells are developed when a particular infection is eradicated by the immune system. These B cells proliferate when the infection returns by producing the same antibodies that were effective against the foreign entity.
Normal colour vision (trichromacy) refers to vision that uses all three types of light cones. People with defected trichromatic vision will be colour blind to some extent and these conditions are called anomalous trichromacy. Three types anomalous trichromacy ( one type of cone perceives light slightly) :
1. Protanomaly – phenotype: reduced sensitivity to red light
2. Deuteranomaly - phenotype: reduced sensitivity to green light
3. Tritanomaly – phenotype: reduced sensitivity to blue
People can also have color blindess as the result of mutation, when loss of function of one cone occurs. This condition is called dichromacy. If there is complete color blindness or monochromacy, the person can’t distinguish any color from grey.
Color blindness is an inherited genetic disorder resulted from mutations on the X chromosome.
