Harry suffers from cystic fibrosis and frequently has periods where he can hardly breathe. the problem is most likely the result of

Which of the following statements is true about the relationship between genetic variation and natural selection? a. genetic variation must be present in a population before natural selection can act on it. b. genetic variation arises in a population as a result of natural selection. c. natural selection can act on a population whether there is genetic variation within the population or not. d. after natural selection acts on a population, the amount of genetic variation in the population always increases.

The term life cycle includes the entire process of: adults defending their young providing a conducive environment adults producing gametes fertilization the growth of the offspring to adulthood

Brian has a medical condition called cone dystrophy, which is a disorder of the cone cells in the eye. what symptoms would you expect brian to have? a. inability to see in the dark b. difficulty determining colors c. difficulty determining shapes and outlines d. inability to see in all light conditions