()a scientist observes that, when the ph of the environment surrounding an enzyme is changed, the rate the enzyme catalyzes a reaction greatly decreases. which statement best describes how a change in ph can affect an enzyme? 1points a a ph change can cause the enzyme to change its shape. b a ph change can remove energy necessary to activate an enzyme. c a ph change can add new molecules to the structure of the enzyme. d a ph change can cause an enzyme to react with a different substrate.

During convection, less dense fluid rises and denser fluid sinks.

Archeologists have discovered three sites showing conclusive evidence for the mastery of fire in tanzania, from a period slightly after the time that homo habilis was present in africa. these sites clearly were founded by homo erectus, the descendent species of homo habilis that migrated north, out of africa and into asia. homo erectus was known to have mastered fire, from ample evidence at sites in asia. there is no reason to attribute mastery of fire to homo ergaster, the descendent species of homo habilis that remained in africa. which of the following is an assumption on which the argument depends? (a) before their migration, homo erectus occupied african territory as far south as tanzania.(b) the strain of migration provided the selective pressure motivating homo erectus‘ mastery of fire.(c) homo ergaster would not have derived as much benefit from the mastery of fire as did homo erectus.(d) homo ergaster inherited all cultural knowledge from homo habilis, a species that did not have mastery of fire.(e) homo ergaster did not occupy regions as far south as tanzania until well after the time of these three sites.

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