Intro To Animal Diversity Flashcards
The presence of what two tissues are the unique defining characteristic of animals?
Nervous and muscular tissue.
What do the nutritional modes of plants and animals differ?
Animals are heterotrophs, where as plants are autotrophs.
What are tissues?
A tissue is a group of cells consisting of one or more cell types that together perform a specialized function.
Describe cleavage.
After a sperm fertilizes an egg, the zygote undergoes rapid cell division called cleavage.
Describe blastula.
A hallow ball of cells that marks the end of the cleavage stage during early embryonic development in animals.
Describe gastrulation.
A series of cell and tissue movements in which the blastula-stage embryo folds inward, producing a three-layered embryo, the gastrula.
Describe gastrula.
An embryonic stage in animal development encompassing the formation of three layers: ectoderm, mesoderm, and endoderm.
Describe Archenteron.
The endoderm lined cavity, formed during gastrulation, that develops into the digestive tract of an animal.
Describe protostome.
Developmental mode distinguished by the development of the mouth from the blastopore. Often also characterized by spiral cleavage and by the body cavity forming when solid masses of mesoderm split.
Describe deuterostome.
A developmental mode distinguished by the development of the anus from the blastopore. Often also characterized by radial cleavage and by the body cavity forming as out pockets of mesodermal tissue.
How do larvae and juveniles differ?
A larva is sexually immature and morphologically distinct from the adult. The juvenile is also sexually immature but resembles an adult.
Describe the major events of the Neoproterozoic era.
Contains early members of the animal fossil record that include Ediacaran biota, which dates from 565-550MYA.
What is meant by Ediacaran biota?
An early group of soft bodied, multicellular eukaryotes known from fossils that range from 565-550MYA.
Describe the events of the Paleozoic Era.
The Cambrian explosion occurred, animal diversity continued but was punctuated by mass extinctions. Vertebrates made the transition to land around 360 MYA.
What is the Cambrian explosion?
A relatively brief time in geologic history when many present-day phyla of animals first appeared in the fossil record. This burst of evolutionary change occurred about 535-525 MYA and saw the emergence of the first large, hard bodied animals.