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30 Cards in this Set

  • Front
  • Back
What is a zygote?
Diploid cell resulting from the union of 2 haploid gametes; 1st cell of 2nd generation.
What is an embryo?
Young plant of animal while it is still contained within a protective structure.
What are the 2 major processes occurring during embryonic development?
Cleavage: cell division.
Gastrulation: in-folding.
What is the process of cleavage?
Its a process forming many cells from one cell.
Zygote-> 2 cells-> 8 cells ->morula (solid ball)-> blastula (hollow ball)-> early gastrula-> late gastrula
What is a gastrula?
Layers of embryonic cells.
What are the germ layers?
What is a ectoderm?
Germ layer.
(The outside layer of cells that's not infolded.)
Epidermis, nervous system.
What is a endoderm?
Germ layer.
(The outer layer of the infolded layer of cells.)
Living of digestive and respiratory system.
What is a diploblastic organism?
Have 2 germ layers.
(endoderm and ectoderm?)
What is a mesoderm?
Germ layer.
(The inner layer of the infolded layer of cells.)
Most internal organs: muscles, skeletal system, heart, stomach.
What is a triploblastic organism?
Have 3 germ layers.
What is an archenteron?
Part of gastrula.
Digestive space (gut cavity).
What is a blastopore?
Part of gastrula.
Mouth or anus.
What are the types of symmetry?
Radially symmetrical.
Bilaterally symmetrical.
What is asymmetry?
No axis divides body into equal halves.
Ex: sponges.
What is radial symmetry?
Along one axis, as long as one cuts through center, body can be divided into equal halves from many angles.
Ex: cnidarians.
What is bilateral symmetry?
Single axis divides body into equal halves.
Midsagittal plane (between eyes).
Ex: platyhelminthes.
What does the development of a digestive tract enable?
Specialization of gut regions.
Sequential food processing.
Continuous operation.
How does a complete digestive tract develop?
Infolding of gastrula.
First opening: blastopore, digestive cavity or tract in middle, then second opening.
What are the 2 different ways to develop a digestive tract?
Protostomes: mouth forms first, and the new opening is the anus.
Deuterostomes: anus forms first, and the new opening is the mouth.
What are protostomes?
Protostome animals are either Ecdysozoans or lophotrocozoans.
What is a Ecdysozoan?
Have an external covering secreted by epidermis that must be shed in order to grow.
What is a lophotrocozoan?
Either a lophopore (ciliated feeding/gas exchange structure) or a trocophore (a ciliated free-living larval form)
What are the 3 types of body plans for a protostome?
1. acoelomate
2. pseudocoelomate
3. coelomate
What is a acoelomate?
A type of body plan for a protostome animal.
No coelom, solid except for digestive space.
What is a pseudocoelomate?
A type of body plan for a protostome animal.
False coelom, and the mesoderm lines the outside of coelom.
Ex: Nematoda.
What is a coelomate?
A type of body plan for a protostome animal.
Mesoderm lines the entire cavity as a "peritoneum".
Ex: earthworm.
What are the 2 ways to make a coelom?
1. schizocoely
2. entercoely
What is schizocoely?
One way to make a coelom.
Splitting within the mesoderm.
In protostomes.
What is entercoely?
One way to make a coelom.
Mesoderm forms pocket from gut.