The answer to number 12 is mate.
Answer:
c. independent variable
Explanation:
#<em>c</em><em>arryonlearning</em>
X - linked traits appear more often in males because males only have one x chromosome. One copy of an x - linked trait is all that a male would need to possess that trait. Females have two x chromosomes, so they would require 2 copies of the x - linked trait in order to possess it.
For evolution to occur:
There must be genetic variation in a population. This provides variation on which natural selection can act. Then natural selection can act by selecting those species which are better adapted to the environmental conditions. Over time those animals that are best suited to the environment only will survive and reproduce. Those organisms successful genes will be preserved and eventually the gene frequency in the population will change, changing the overall characteristics of a population. This is how evolution occurs.
Answer:
commensalism
an association between organisms in which one benefits and the other derives nor harm
