Exam 21: Animal Development

In animal development, the formation of complex three-dimensional organs involves a number of morphogenetic processes. These include 1)localised cell proliferation 2)migration of individual cells to new sites 3)thickening and infolding of epithelial sheets 4)programmed death of localised groups of cells 5)disaggregation of tissues into individual cells. Which of the following lists these processes, in the order they are likely to begin, during normal embryonic development of a limb bud in mammals or birds?

In an experiment on an early frog embryo, cells from the region that will eventually form the neural plate were transplanted to another part of the blastula. It was noticed that the transplanted tissue formed a second neural plate later in the embryo's development. The best explanation for this observation is that

Which of the following mutant Drosophila phenotypes resulted from a mutation in a pair-rule gene?

Maternal-effect genes are

In addition to organogenesis, many animals undergo a further stage of development called

Morphogenic changes during organogenesis are generated by

You observe an animal embryo that is more-or-less spherical in shape. Projecting from the surface along one 'side' of the embryo is a pair of ridges, separated by a shallow groove. A transverse section through the embryo, perpendicular to these ridges, shows that the interior of the embryo is a fluid-filled cavity, and that the body wall consists of three layers of cells. This embryo is undergoing

Which of the following is NOT a process involving epithelial to mesenchymal transition?

In Drosophila, mutations in homeotic genes can lead to

A maternal-effect gene is

Gastrulation

Cells produced specifically during cleavage are called

Haematopoietic stem cells give rise to

Hox genes

Which of the following types of stem cells have the potential to give rise to the greatest variety of different cell types?

The order of embryo development is

In animal development, cleavage refers to

During cleavage, the

Drosophila melanogaster is a useful species for the study of developmental genes because

A blastula that is spherical in shape, with blastomeres of approximately equal size in a single layer around the central blastocoel, is most likely to be that of a