Cell differentiation is the process by which cells become specialized and take on specific roles in an organism. nearly all cell types in a multicellular organisms contain the same dna, yet they express their genes differently. gene expression describes the way in which genetic information is put into action and influences how cells differentiate. what do you know about cell differentiation in multicellular organisms? check all of the statements that are true. proteins play a key role in cell differentiation. the external environment, specifically temperature, during the development of turtles and some other reptiles to determine the sex of hatching offspring different transcription factors are associated with the differentiation 
of stem cells into bone, muscle, 
and nerve cells. transcription factors bind to regulatory regions of a gene and affect their expression. the amount of available light or daylength to determine the 
patterns of gene expression 
that lead to flowering in some plants.

I believe all of these answers are correct. Proteins play a key role in cell differentiation. The external environment, specifically temperature, during the development of turtles and some other reptiles helps to determine the sex of hatching offspring Different transcription factors are associated with the differentiation 
of stem cells into bone, muscle, 
and nerve cells. Transcription factors bind to regulatory regions of a gene and affect their expression. The amount of available light or day length helps to determine the 
patterns of gene expression 
that lead to flowering in some plants.

The answer is a if u read the definition it makes sense

Mantle convection  is the slow  creepingmotion of earth's solid silicate  mantle  caused by  convection  currents carrying  heat from the interior  to the planet's surface.[1][2]  the earth's surface  lithosphere, which rides atop the  asthenosphere  (the two components of the  upper mantle), is divided into a number of  plates  that are continuously being created and consumed at their opposite  plate boundaries. accretion occurs as mantle is added to the growing edges of a plate, associated with  seafloor spreading. this hot added material cools down by  conduction  and  convection  of heat. at the consumption edges of the plate, the material has thermally contracted to become dense, and it sinks under its own weight in the process of  subduction  usually at an  ocean trench.[3]this subducted material sinks through the earth's interior. some subducted material appears to reach the lower mantle,[4]  while in other regions, this material is impeded from sinking further, possibly due to a phase transition from  spinel  to  silicate perovskiteand  magnesiowustite, an  endothermic reaction.[5]the subducted oceanic crust triggers  volcanism, although the basic mechanisms are varied. volcanism may occur due to processes that add buoyancy to partially melted mantle causing an upward flow due to a decrease in density of the partial melt.secondary forms of convection that may result in surface volcanism are postulated to occur as a consequence of intraplate extension[6]  and  mantle plumes.[7]it is because the mantle can convect that the  tectonic plates  are able to move around the earth's surface.[8]mantle convection seems to have been much more active during the  hadean  period, resulting in gravitational sorting of heavier molten  iron, and  nickel  elements and  sulphides  in the core, and lighter  silicate minerals  in the  mantle.