In the 1600's, robert hooke, and english scientist, used a crude microscope to examine bits of cork. cork is derived from the bark layer of certain trees. upon seeing the cork under the microscope, hooke named the spaces within the cork 'cells', because they looked like empty rooms of a monastery. although he coined the term cell, an ironic feature of cork is that it is dead plant material. knowing this, what feature of cells would robert hooke not have been able to observe under the microscope while looking at cork? a) he would not have been able to estimate the size of cork cells. b) he would not have been able to observe the cell walls of the cork. c) he would not be able to observe cork cells dividing to form new cells. d) he would not have been able to observe the rectangular nature of plant cells.

Of the pollutants that form acids in the atmosphere, which is easiest to reduce? a. sulfur dioxide b. nitrogen dioxide c. ozone d. carbon monoxide

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.

Why do mountaineers become breathless as they reach high altitudes