Bio 123: PP10 Material Flashcards
What is a timeline characteristic of animals?
They are much younger in terms of evolution when compared to protists and fungi
When did animals first make an appearance?
First animals were seen around 800 million years ago
What is a timeline characteristic of Dino’s?
They were extinct about 65 million years go
Choanoflagellate
-Most animal like protists
-Are unicellular
-Scientists believe that extant animals today are related to choanoflagellates
Why types of cells to sponges have and what are they used for?
-Collar cells known as Choanocyte
-Are mainly used for feeding
-Choanocyte structures are similar to individual choanoflagellates
Sponges
-Are the most ancient animals on the planet
-They lack true tissue
-Have Choanocyte (collar cells)
What are the 5 general characteristics of animals?
1)Are multicellular, most having tissues, organs, and organ systems
2)Are aerobic heterotrophs
3)Most species reproduce sexually
4) Most species at some stage of life have mobility
5) Lack cell walls
What are some organ systems that animals have?
-Digestion system
-Excretory system
-Circulatory system
Define vertebrates and give examples
Animals that have a backbone
-Includes mammals, birds, reptiles, amphibians, and fishes
Define invertebrate and give examples
Animals that lack a back bone
-Beatles and insects
Invertebrate diversity
Make up over 95% of the known species of animals
Cell membrane
Animals contain a cell membrane that regulates what comes in and out of the cell
Arthropods
The most diverse phylum of animals
Habitat of Sponges
Sponges mainly occupy the marine floor and coral reefs
What are the types of body symmetry of animals?
Radial or Bilateral
Bilateral symmetry
Only has one plane of symmetry through the animals body
Radial symmetry
Animals that have infinite planes of symmetry
Ancestral state
Older and evolved first
Derived state
Trait that came later in evolutionary time
Cephalization
Evolutionary trend of the concentration of sense organs and nerve control that is towards the anterior end of the body (all senses developed in places where they can have close communication with our brain)
e.g. our eyes, ears, mouth, nose, tongue are all sensory organs that developed in the close regions to the brain
What are the terms that describe body regions?
Anterior
Posterior
Dorsal
Ventral
Anterior
Towards the head
Posterior
Towards the tail
Dorsal
Towards the upper part or back of the standing animal
Ventral
Towards the lower part or belly of the standing animals
What is an exception to symmetry?
Sponges are animals but lack symmetry all together
Characteristics of cephalization
Increased cephalization can be found in more complex animals while simpler animals will have decreased cephalization
What is the general embryonic development of animals?
1) Zygote
2)Cleavage (8 cell stage)
3) Blastula
4) Gastrulation (folding in beings)
Mesoderm
Is the development of a third embryonic germ layer that comes later in some animals
Cleavage
The fertilized zygote undergoes rapid mitotic divisions and creates the cleavage
Blastula
Spherical shape and has a hollow inside called the blastocoel
-coel
Meaning cavity/empty
Blastocoel
Hollow inside of the blastula
Gastrulation
Occurs when the blastocoel begins to start folding in on itself
Grastula
Once gastrulation is complete the entire structure of the cell body is called the gastrula
What are the layers of the Grastula?
1) Blastocoel
2)Endoderm
3) Ectoderm
4) Archenteron
5)Blastopore
Ectoderm
Most outer layer of a gastrula
Blastocoel of the Gastrula
The original empty hollow space that we have during the blastula phase
Endoderm
Inside fold on the gastrula
Archenteron
Is a second hollow space that forms as a result of the endoderm forming
Blastopore
Entrance to the archenteron
Embryonic germ layer
Any cell that is undifferentiated, in which other structures will eventually develop within the animals
What are the general tissue layers in an embryo?
- Ectoderm
-Endoderm
-Mesoderm
Ectoderm
Start of the tissue that lines the body surface
What are some examples of the ectoderm?
- Epidermis of skin and its derivatives (includes hair follicles, sweat glands)
-Lining of the mouth and anus
-Cornea and lens of eye
-Tooth enamel
-Sensory receptors in the skin
-nervous system
Mesoderm
The source of muscles and provides structure and support
** only forms in triploblastic animals
What are some examples of mesoderm?
-Skeletal system
-Muscular system
-Adrenal cortex
-reproductive system
circulatory and lymphatic system
-lining of body cavity
Endoderm
Develops int the inner gut lining and includes the liver and pancreas
What are some examples of the endoderm?
-Liver
-Pancreas
-Epithelial lining of digestive tract
-Epithelial lining of the respiratory system
-Thyroid and parathyroid glands
Diploblastic
Only contains the ectoderm and the endoderm and is the ancestral state
Triploblastic
Have the ectoderm, endoderm, and the mesoderm and is the derived state
Coelom
A fluid or air-filled space located between the digestive tract and the outer body wall
What is the function of the coelom?
Is to provide cushion in order to prevent injury to internal organs, it also enables organs to grow and move independently of the outer body wall.
What is an evolutionary characteristic of coelom?
The ancestral form are animals lacking coelom all together
Acoelomates
-Animals that lack a coelom which automatically limits their growth.
-The outside of their bodies is continuous with all their internal structures
- ancestral form
Coelomate animals
Animals that have a true coelom which forms from the mesoderm
-this is the most derived state
-all vertebrates are coelomate animals
Pseudocoelmates
Form both from the mesoderm and the endoderm (ancestral to coelomate characteristics).
-Very rare in aniamls
Why must acoelomate remain small in body size?
***Because their organs are attached to their skin and if the skin grows then their internal organs would burst?
(cant remember this one, double check answer!!)
Protostome Development
-Is the ancestral path
-has spiral cleavage
-In its earliest stage of development, the cells have already been designated for a specific function (determinant)
Deuterostome Development
-The derived path
-Has radial cleavage
-First developing cells are undergoing cleavage and these cells have yet to be given a function (these cells are known as stem cells)
What are the key comparisons of protostome and deuterostome development?
1) Cleavage
2)Determination of earliest cells
3)Coelom Formation
4) Fate of the blastopore
What is the fate of the blastopore?
In protostome development, the mouth develops from the blastopore.
In deuterostome development, the anus develops from the blastopore.
Spiral Cleavage
Cells divide in a circular motion around the polar axis of the mass of dividing cells
Radial Cleavage
Cells divide towards the polar axis.
What do morphological and molecular data agree on?
1) all animals share a common ancestor- the protists colonial flagellate
2) Sponges are the most ancestral animals
3)Eumetazoa is a clade of animals with true tissue
4) Most animals demonstrate bilateral symmetry
5)Chordates and Echinoderms are deuterostomes
What are some examples of Molecular data?
Hox genes, nuclear genes, mitochondrial genes.
What are the two most ancient groups of animals?
The poriferans and the Cnidarians
What is the most ancestral animal domain?
The metazoa which includes the porifera (sponges)
