What hypotheses have been proposed to explain how prions evolve? Select the TWO answers that are correct.
a. When the environment changes, one of the less common variants in a prion population may be able to better spread and become the dominant type of prion.
b. Prions respond to environmental changes by bonding with other prion variants in the population and potentially forming new variants able to handle the change.
c. Changes in the environment change the shape of some prions, possibly producing a variant that is better able to tolerate the change than the original type of prion.
d. Environmental changes cause some prions to break into small segments that may be better able than larger prions to survive and reproduce in the new environment.

Autotrophs a. consume their food to get energy b. may use photosynthesis to gain energy c. are also called consumers d. cannot use solar energy

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.

The fascicles of the deltoid are ; the fascicles of the pectoralis parallel; bipennate fusiform; unipennate multipennate; triangular bipennate; fusiform