Campbell
Terms : Hide Images
| 317462886 | cleavage | (embryology) the repeated division of a fertilised ovum | |
| 317462887 | blastula | The hollow ball of cells marking the end stage of cleavage during early embryonic development | |
| 317462888 | gastrula | An embryonic stage in animal development encompassing the formation of three layers: ectoderm, mesoderm, and endoderm. | |
| 317462889 | larva | the immature free-living form of most invertebrates and amphibians and fish which at hatching from the egg is fundamentally unlike its parent and must metamorphose | |
| 317462890 | metamorphosis | the marked and rapid transformation of a larva into an adult that occurs in some animals | |
| 317462891 | grade | A group of organisms that share the same level of organizational complexity or share a key adaptation. | |
| 317462892 | parazoans | phylum porifera (sponges) | |
| 317462893 | eumetazoans | member of the clade of 'true animals', the animals with true tissues (all animals except sponges) | |
| 317462894 | radiata | Members of the radially symmetrical animal phyla, including cnidarians. | |
| 317462895 | radial symmetry | the property of symmetry about an axis | |
| 317462896 | bilateria | Members of the branch of eumetazoans possessing bilateral symmetry. | |
| 317462897 | bilateral symmetry | arrangement of body parts so there are distinct left and right halves that mirror each other | |
| 317462898 | dorsal | back | |
| 317462899 | ventral | Front | |
| 317462900 | germ layers | Tissue layers in the embryos of all animals except sponges, ectoderm, mesoderm, endoderm | |
| 317462901 | ectoderm | The outermost of the three primary germ layers in animal embryos; gives rise to the outer covering and, in some phyla, the nervous system, inner ear, and lens of the eye | |
| 317462902 | endoderm | The innermost of the three primary germ layers in animal embryos; lines the archenteron and gives rise to the liver, pancreas, lungs, and the lining of the digestive tract | |
| 317462903 | archenteron | The endoderm-lined cavity, formed during gastrulation, that develops into the digestive tract of an animal. | |
| 317462904 | diploblastic | Having two germ layers. | |
| 317462905 | triploblastic | has three germ layers: the ectoderm, endoderm, and mesoderm. | |
| 317462906 | mesoderm | the middle germ layer that develops into muscle and bone and cartilage and blood and connective tissue | |
| 317462907 | acoelomate | an animal that lacks a coelom, or body cavity | |
| 317462908 | body cavity | A fluid-containing space between the digestive tract and the body wall. | |
| 317462909 | pseudoceolomate | an organism in which the ceolom is not completely covered by the mesoderm | |
| 317462910 | coelomates | An animal that possesses a true coelom (a body cavity lined by tissue completely derived from mesoderm). | |
| 317462911 | coelom | a body cavity completely lined with mesoderm | |
| 317462912 | protostomes | Organisms that first forms a mouth when it develops from the blatopore. | |
| 317462913 | deuterostomes | Undergoes radial cleavage and the anus forms before the mouth. | |
| 317462914 | spiral cleavage | A type of embryonic development in protostomes, in which the planes of cell division that transform the zygote into a ball of cells occur obliquely to the polar axis, resulting in cells of each tier sitting in the grooves between cells of adjacent tiers. | |
| 317462915 | determinate cleavage | A type of embryonic development in protostomes that rigidly casts the developmental fate of each embryonic cell very early. | |
| 317462916 | radial cleavage | A type of embryonic development in deuterostomes in that the planes of cell division that transform the zygote into a ball of cells are either parallel or perpendicular to the polar axis, thereby aligning tiers of cells one above the other. | |
| 317462917 | indeterminate cleavage | A type of embryonic development in deuterostomes, in which each cell produced by early cleavage divisions retains the capacity to develop into a complete embryo. | |
| 317462918 | schizocoelous | In protosomes, a pattern of development in which a solid mass of mesoderm cells splits to form the cavity that becomes the coelom. | |
| 317462919 | enterocoleous | in deuterostomes when development begins as buds from the archenteron | |
| 317462920 | blastopore | The opening of the archenteron in the gastrula that develops into the mouth in protostomes and the anus in deuterostomes | |
| 317462921 | Lophotrochozoa | a clade that encompasses the annelids, mollusks, and several other phyla, they are distinguished by two morphological features, the lophophore, a crown of tentacles used for feeding,and the trochophore larva, a distinct larval stage | |
| 317462922 | Ecdysozoa | One of two distinct clades within the protostomes. It includes the arthropods and animals that molt as they grow. | |
| 317462923 | trochophore larva | Distinctive larval stage observed in some lophotrochozoan animals, including some annelids and molluscs. | |
| 317462924 | Ediacaran period | the last period during the Precambrian period, when there was extensive glaciation, which delayed further evolution on earth | |
| 317462925 | Cambran explosion | 545 to 525 mya all major body plans evolved examples are in the fossils of the Burgess Shale | |
| 317462926 | lophopore | water is circulated and food removed through a funnel fringed with cilia |
