Which of the following statements support(s) the theory of the endosymbiotic origin of mitochondria and plastids? Mitochondria and plastids have circular DNA and replicate by splitting.
Mitochondria and plastids have ribosomes.
Mitochondrial and plastid ribosomal RNA sequences are more similar to cytoplasmic ribosomes than to bacterial ones.
The inner membranes of plastids and mitochondria have transport proteins homologous to those in bacterial plasma membranes.
I only
I and II only
III only
I, II, and IV

answer; a male inherits only one allele of the x-linked gene controlling hair color;

you did not attach the discourse, but i assume it to be the discourse on the origin and basis of inequality among men (the original titile in french is: "discours sur l'origine et les fondements de l'inégalité parmi les hommes"), also know as "second discourse". in this discourse, jean-jacques rousseau emphasizes that private property is the basis of all inequalities.

therefore, what enabled the old regime to maintain as long as it did was private property.

the answer to you question is   jet streams

genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).