maternal substances that affect devel of cells that inherit them during early mitotic divisions of they zygote.
the process by which an animal takes shape and the differentiated cells end up in the appropriate locations.
hydrolytic enzymes released from the acrosome make a hole in the jelly coat, while growing actin filaments form acrosomal process.
fast block to polyspermy
depolarization prevents additional sperm cells from fusing with the egg's plasma membrane.
fusion with the egg's plasma membrane of numerous vesicles lying in the egg's cortex.
vesicles located under the plasma membrane of an egg cell that undergo exocytosis during the cortical reaction.
slow block to polyspermy
formation of the fertilization envelope and other changes in the egg's surface that prevent fusion of the egg with more than one sperm.
A type of cleavage in which there is complete division of the egg, as in eggs having little yolk (sea urchin) or a moderate amount of yolk (frog), but not a lot of yolk (like birds)
set of cells on or nera surface of blastula moves to interior location, 3 cell layers establish, and primitive digestive tube is formed
The development of organ rudiments from the three germ layers. Includes neurlation:(notocord, and nuearl tube formation)
lower layer of trophoblast, the inner germ layer that develops into the lining of the digestive and respiratory systems
encloses yolk in egg of reptiles, in mammels it is the site of early formation of blood cells
A stiff but flexible rod that supports a chordate embryo's back that becomes backbone in adults. from cells in dorsal mesoderm.
will become the animals central nervous system. from the infolding of etodermal neural plate
develops into the lining of the digestive and respiratory systems, thymus, thyroid, parathyroid,
skin, sweat glands, follicles, nervous/sensory systems, pituaty gland, jaws/teeth,germ cells
skeletal/muscualr, ciruclatory, lymphatic, excretory, reproductive, dermis of skin,and adrenal cortex
Fetal membrane that forms a fluid-filled sac around the embryo (in mammals and reptiles/birds)
A process in which the cells of a tissue layer rearrange themselves, so that the sheet of cells becomes narrower (converges) and longer (extends). happens in gasturaltion and organogenesis
Signals to which genes regulating development respond, indicating a cell's location relative to other cells in an embryonic structure.
apical ectodermal ridge
A limb-bud organizing region consisting of a thickened area of ectoderm at the tip of a limb bud.
zone of polarizing activity
anterior/posterior vertebrate limb development; dictates anterior/posterior axis; located in posterior mesoderm
cell adhesion molecules
specific membrane proteins that allow cells to identify the tissue that they begin with, cells that belong to a specific type of tissue will have cell adhesion molecules that they are complimentary to each other, these proteins will fit into eachother and attach the individual cells to other cells in their specific tissue. if one of these cells break away from their tissue, these cell adhesion molecules will evolve into an enzyme that will initiate apotosis(programmed cell death) in order to prevent a cell from a different tissue type from existing in a tisse where it does not belongto
The maternal substances in the egg that influence the course of early development by regulating the expression of genes that affect the developmental fate of cells.
multicellular embryo consisting of smaller cells called blastomeres
During cleavage the single large zygote is converted into a _____
Cell division is restricted to a small disk of yolk-free cytoplasm at the animal pole of the zygote.
Which of the following is true of meroblastic cleavage?
As an animal develops, organs form and the body transforms into a shape typical of the species, in a process called _____.
there is an opening from the cavity inside the gastrula to the outside
difference between the blastula and gastrula stages of development is that _____.
The digits of a developing vertebrate limb respond to molecules that establish an anterior-posterior axis. These molecules originate in _____.
a defect in motile cilia that renders them immotile
People with Kartagener's syndrome suffer from a variety of ailments, including the intriguing condition known as situs inversus, a reversal of the abdominal and thoracic organs. This condition occurs because of _____.
Sonic hedgehog gene
Produced at the base of LIMB BUDS in the ZPA (zone of polarizing activity). Mediates ECTODERMAL functions, and patterning along anterior-posterior axis.
fertilization envelope wouldn' develope
In an egg cell treated with EDTA, a chemical that binds calcium and magnesium ions, the
) In mammals, the nuclei resulting from the union of the sperm and the egg are first truly diploid at the end of the
meroblastic development, which is typical of birds
The pattern of embryonic development in which only the cells lacking yolk subsequently undergo cleavage is called
yolk of frog egg
supports the higher rate of cleavage at the animal pole compared to the vegetal pole.
A solid clump of cells resulting from cleavage in the early embryo. Because there is very little growth of these cells during cleavage, the morula is ony about as large as the original zygote.
cleavage → morula → blastula → gastrula
Which of the following correctly displays the sequence of developmental milestones
Some of these women gave birth to children with arm and leg deformities, suggesting that the drug most likely influenced
gastulation, organogenisis and cleAVGE
Changes in both cell shape and cell position occur extensively during
medail to lateral
Which of the following is the anatomical axis that is largely symmetrical in both frogs and humans?
) P granules of mRNA and protein
The developmental precursors to the gonadal tissues of C. elegans uniquely contain
arrangement of organs and tissues in their characteristic places in 3-D space defines