Organism Development Flashcards
What are the two developments, and what are their basic stages?
Direct development: embryo to adult
Indirect development: embryo to larva to adult.
What is spermatogenesis?
The formation of sperm. The spermatogonia produces primary spermatocytes via mitosis, which then further divide via meiosis until they become spermatozoa.
Describe cleavage.
The rapid cell division after fertilization,
What are the three types of fertilized eggs?
Mesolecithal, Telolecithal, and Isolecithal.
Which types of animals have spiral cleavage?
Protostomes.
Which types of animals have radial cleavage?
Deuterostomes.
What is a blastula?
A many, many celled embryo with a hollow center.
What process forms the germ layers?
Gastrulation.
List five characteristics of Deuterostome development.
- radial cleavage
- regulative embryo
- blastopore becomes ass first, mouth second
- coelom forms by outpocketing (enterocoely)
- regulative development; cell fate is determined by interactions with neighboring cell
List five characteristics of Protostome development.
- spiral cleavage
- mosaic embryo
- blastopore becomes mouth first, ass second
- coelom forms by splitting (schizocoely)
- mosaic development; cell fate is determined by the cytoplasm inherited during cleavage
What are the two functional ways to make a coelom?
- ) schizocoely (protostomes, forms by splitting)
2. ) enterocoely (deuterostomes, forms by outpocketing)
What are the three germ layers possible?
The ectoderm (outer), mesoderm (middle), and endoderm (inner)
What two main phylum are neither protostomes nor deuterostomes, and why are they not?
- ) Porifera, because they have no true germ layers or tissues, as well as having no developmental symmetry.
- ) Cnidaria, because they have radial symmetry (rather than bilateral symmetry).
What two phyla are the only ones with radial symmetry?
Cnidaria and Echinodermata.
What are the three main systems of birth?
oviparous: egg birth
lecithotrophic viviparity: keeping eggs in the body to grow
matrotrophic viviparity: nurturing offspring that is live at birth
What is “parthenogenesis”?
Reproduction of females without males. Unisexual reproduction.
What are the three defining characteristics of all in the Kingdom Animalia?
- ) Multicellular
- ) Heterotrophic
- ) Eukaryotic
What was the Cambrian Explosion, and how long ago was it?
The evolutionary event that gave rise to all major body plans that exist today. 600 mya.
What are the four types of tissues?
- connective tissues
- nervous tissues
- epithelial tissues
- muscle tissues
Tell me about epithelial tissues.
They cover surfaces (including the outside of the body as well as organs inside). They are classified by the number of layers present and the shape of their cells.
Tell me about connective tissues.
They are widely spaces cells surrounded by an extracellular matrix. They can be loose (areolar) or dense. CT is found in cartilage, bone, and blood.
Three types of muscle tissues:
- skeletal
- cardiac
- smooth
Two cell types of nervous tissues:
- neurones
- glial cells
From where does the coelom come from?
The mesoderm.
What is the difference between a blind gut and a complete gut?
Blind gut has one opening (mouth), and the complete gut has two (mouth and anus).
What is a pseudocoelomate?
An organism that has a “false” body cavity, or rather, a body cavity that functions regularly but lacks a mesodermal lining that wraps around. the gut.
What is the general term for animals that have any number of body tissues and organs?
Metazoans.
