Sebaceous secretions associated with hair follicles that secrete an oily, odorous, messy secretion are due to what type of secretion mechanism?

Look at the figure above. which atmospheric layer has around 80 percent of the mass of the earth's atmosphere? (hint: it's where the clouds seen on earth are formed.) a. exosphere b. troposphere c. stratosphere d. thermosphere

Color blindness is a recessive trait. the gene for color blindness is on the x chromosome. the family tree below shows the trait of color blindness. the only unknown is the mother in the first generation

What noticeable trend from this graph might be used to make a conclusion?