#Question id: 7150
#Unit 5. Developmental Biology
What is the role of semaphorins and Eph ligands in development of the nervous system?
#Question id: 7151
#Unit 5. Developmental Biology
In developmental biology, what is meant by the concept of
"growth"?
a) Growth occurs through increases in cell size.
b) Growth occurs through increases in cell number.
c) Growth can result from increases in the volume of extracellular
matrix between cells.
d) Cell death is an important determinant of overall growth.
Which of the following is correct?
#Question id: 7152
#Unit 5. Developmental Biology
The size of a cell is generally controlled by the amount of DNA in the nucleus: the more DNA, the larger the cell. What do experiments in which the amount of DNA is doubled (tetraploidy in salamanders) tell us about growth control?
#Question id: 7153
#Unit 5. Developmental Biology
What are osteoblasts?
#Question id: 7154
#Unit 5. Developmental Biology
Cancer is believed to often arise from stem cells, rather than fully differentiated cells. Which of the following are consistent with this view?
#Question id: 7155
#Unit 5. Developmental Biology
What does it tell us about aging that cells from different organisms are capable of a fixed number of divisions in culture, and that number of divisions reflects the relative life-span of the organism?