49 The diagram shows how specialized body cells can develop.
Totipotent
Pluripotent
Stem Cells
Stem Cels
Specialized
Stem Cells
Can develop into
any type of body
call
can develop into
almost any body
cell, including other
pluripotent cells
can develop into
specific cell types,
such as nerve or
blood cells
Specialized
Cells
Ces com
Which of the following best explains why cells that contain the same genetic material do not develop into the
same types of cells?
А
Because internal or external stimull can trigger the activation of specific genes in the DNA of cells
Because random mutations can occur in the DNA of cells during early embryonic development
Because messenger RNA is converted to transfer RNA when cell differentiation begins
Because chemical signals that are released during the cell cycle can result in the linking of similar genes
С
D
D

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.