3. helps make animal membranes more rigid.

Alaska and northern canada have a diet rich in vitamin d and their skin color is darker than predicted on the basis of iv intensity at their latitude. explain the observation:

Agroup of students are walking in the park, and one of them takes a picture of a pollen grain that is being blown by the wind.what caption can the student use for this picture? fahrte "littl1111111nimmt-hhhfull film# # #gene mutation in actiongene flow at workgenetic drift as it happensnatural selection in progresshii

How have high taxes on tobacco products impacted the number of people who use them? a. the number of tobacco users has increased. b. the number of tobacco users has decreased. c. the number of tobacco users has not changed. d. the number of adolescent tobacco users decreased, while the number of adult users increased