The answer is B) Genetic variation
bring change in the genetic basis of a population
The probability of transmitting both traits to his son is Zero. This is because the son has one X chromosome and one Y chromosome (XX), therefore since the traits are linked to the X chromosomes, it means the son will only be a carrier but will not show the trait phenotypically.
Nitrogen Fixation: Root and Bacteria Interactions. Nitrogen is an important macronutrient because it is part of nucleic acids and proteins. ... The most important source of BNF is the symbiotic interaction between soil bacteria and legume plants, including many crops important to humans.