Which statements are true? Explain why or why not.1 In the early cleavage stages, when the embryocannot yet feed, the developmental program is driven andcontrolled entirely by the material deposited in the egg bythe mother.2 Because of the many later developmental trans-formations that produce the elaborately structured organs,the body plan set up during gastrulation bears little resem-blance to the body plan in the adult.3 As development progresses, individual cellsbecome more and more restricted in the range of cell typesthey can give rise to.4 At different stages of embryonic development,the same signals are used over and over again by differentcells, but with different biological outcomes.5 Changes in the coding regions of genes involved indevelopment are primarily responsible for the differencesbetween species. 6 The cell cycle is the ticking clock that sets thetempo of developmental processes, with maturationalchanges in gene expression being dependent on cell-cycleprogression.
Which statements are true? Explain why or why not.
1 In the early cleavage stages, when the embryo
cannot yet feed, the developmental program is driven and
controlled entirely by the material deposited in the egg by
the mother.
2 Because of the many later developmental trans-
formations that produce the elaborately structured organs,
the body plan set up during gastrulation bears little resem-
blance to the body plan in the adult.
3 As development progresses, individual cells
become more and more restricted in the range of cell types
they can give rise to.
4 At different stages of embryonic development,
the same signals are used over and over again by different
cells, but with different biological outcomes.
5 Changes in the coding regions of genes involved in
development are primarily responsible for the differences
between species.
6 The cell cycle is the ticking clock that sets the
tempo of developmental processes, with maturational
changes in gene expression being dependent on cell-cycle
progression.
Step by step
Solved in 2 steps
