Many cases of severe combined immunodeficiency result from mutations in adenosine deaminase (an enzyme involved in nucleic acid turnover). Deficiency of this enzyme's activity leads to a 100-fold increase in dATP, yet also causes a deficiency in dNTPs required by lymphocytes for replication and proper immune function. Explain.

On a recent expedition to a remote region of northern canada, scientists uncovered skeletal remains from about 100,000 years ago. surprisingly, all the skeletal remains, which included many species from differing biological families and spanned about two thousand years, showed evidence of experiencing temperatures in excess of 1000 degrees fahrenheit (or 538 degrees celsius). which of the following, if true, best explains the apparent paradox between the cold environment and the evidence of the bones experiencing hot temperatures? (a) chemical changes that naturally occur during the process of decay in only one north canadian species produce the same evidence of the species' skeletons being exposed to hot temperatures as the expedition scientists found. (b) a little over 103,000 years ago, a large fire is known to have occurred in northern canada. (c) strong evidence exists that as early as 70,000 years ago, homo sapiens around the world relied heavily on fire to cook animals. (d) in the same expedition and in roughly the same layer of excavation, scientists found rudimentary wood cutting and hunting tools used by early humans.

Which of the following is most likely the result of an organism having lipids in its body a) water cannot be absorbed through the surface of a leaf b)human eats fruits to get a quick source of energy c) a sheep sleeps for more hours in the winter d) a warm river is filled with fish and algae

What process creates gametes? a.fertilization b.mitosis c.meiosis