chapter 28

Question 1

complex multicellularity

Answer 1

having a nucleus and other complex organelles

Question 2

simple multicellularity

Answer 2

nearly every cell is in direct contact with the external environment

Question 3

diffusion

Answer 3

the random motion of individual molecules, wit net movement occurring where there are areas of higher and lower concentration of molecules

Question 4

bulk transport

Answer 4

the movement of molecules through organisms due to pressure differences at rates beyond those possible by diffusion across a concentration gradient

Question 5

meristems

Answer 5

a discrete population of actively diving, totipotent cells, apical meristems are located at the tip of stems and roots and produce cells that allow plant to grow in length, while lateral meristems surround stems and roots and produce cells that allow growth in diameter

Question 6

blastula

Answer 6

a fluid-filled ball of undifferentiated cells formed after the fertilized egg has undergone several round of mitotic cell division following the morula stage

Question 7

gastrula

Answer 7

a layered structure formed when the inner cell mass cells of the blastocyst migrate and reorganize

Question 8

evo-devo

Answer 8

the short name for evolutionary-development biology, a filed of study that compares the genetic programs for growth and development in species on different branches of phylogenetic reconstructions