A. homologous chromosomes
b. sex chromosomes
c. autosomes
In humans gene flow usually comes about through the actual migration of human populations, either voluntary or forced. Although gene flow does not change allele frequencies for a species as a whole, it can alter allele frequencies in local populations.
Hopefully this helps.
I believe the correct answer among the choices listed above is option B. A gland secretes enzymes through a duct onto the surface of a body part is a salivary gland. It is under the classification of exocrine glands. Hope this answers the question.
