Chapter 47 - Animal Development

Positional information

________ changes with location and cells in a growing embryo receive and respond to it.

Morphogenesis

________ is the process through which cells change the form, location, and survival in animals.

plasma membrane

To reach the ________, sperm must first dissolve or enter any protective layer around the egg.

cell surface

The ________ processes that occur during fertilization have been investigated most thoroughly in sea urchins, which are members of the phylum.

cortical response

The ________ alters the zona pellucida in mammalian fertilization as a gradual impediment to polyspermy.

Neurulation

________ is an early process in vertebrate organogenesis that involves the creation of the notochord by cells of the dorsal mesoderm and the development of the neural tube from infolding of the ectodermal neural plate.

fetal placenta

The trophoblast starts the creation of the ________, while the embryo properly develops from a cell layer within the blastocyst called the epiblast.

rudimentary digestive cavity

Gastrulation transforms the blastula into a gastrula, which contains a(n) ________ and three germ layers: ectoderm (blue), which creates the embryo's outer layer, mesoderm (red), which develops the middle layer, and endoderm (yellow), which forms the embryo's interior tissues.

Cytoskeletal rearrangements

________ alter the morphology of cells, which underpin cell motions in gastrulation and organogenesis, such as invaginations and convergent extension.

Organs

________ develop from particular parts of the three embryonic germ layers.

volume

The ________ and distribution of yolk have a significant impact on the pattern of cleavage.

mammalian embryos

Bird, reptile, and ________ grow within a fluid- filled sac enclosed within a shell or the uterus.

cleavage stage

In many species, the completion of the ________ results in the formation of a blastula with a fluid- filled chamber, known as the blastocoel.

Cell fate

________ is controlled by cytoplasmic determinants and inductive cues.

Molecules

________ and events on the egg surface are critical in all stages of fertilization.

Embryo destiny maps

________ developed experimentally indicate that certain areas of the zygote or blastula grow into specific portions of older embryos.

polyspermy occurs

If ________, the embryo will die as a result of the improper amount of chromosomes.

cytoskeleton

The ________ is also involved in cell migration, which is aided by cell adhesion molecules and the extracellular matrix.

embryonic development progresses

As ________, the developmental capacity of cells in all animals becomes progressively more restricted.