Unit 4 Flashcards
Zygote
fertilized egg
Cleavage
mitotic divisions
Morula
solid ball of cells
Blastula
hollow ball, space fills with fluid
Gastrulation
cell movement, shape changes, and divisions
Embryo
multicellular development stage
Tissue
Cells of animals (except sponges) organized
into structural and functional units
Radial Symmetry
Body parts arranged around central axis
* Can be divided into two equal halves by any plane that
passes through the center
Bilateral Symmetry
Body has right and left halves that are mirror images
* Only sagittal plane bisects animal into two equal halves
Cephalization
Evolution of a definite brain area
Totipotent
Can give rise to all other body cells
How many Germ layer
are there
three: ectoderm, mesoderm, endoderm
Ectoderm
body
coverings and nervous
system
Mesoderm
skeleton and muscles
Endoderm
digestive
organs and intestines
Body Cavity
Space surrounded by mesoderm tissue
formed during development
Acoelomate
No body cavity
Pseudocoelomate
Body cavity between mesoderm
and endoderm
Coelomate
Body cavity entirely within the mesoderm
Protostome
first opening in blastula becomes mouth
Deuterostome
first opening in blastula becomes anus,
mouth develops later
Cnidaria
branch off evolutionary tree before Bilateria
Parazoa
Animals lacking tissues (and therefore organs) and
a definite symmetry
Eumetazoa
Animals with definite shape and symmetry,
tissues; possibly organs and organ systems
Porifera
Phylum Porifera - sponges
Spicules
needles of calcium carbonate
Spongin
reinforcing tough protein fibers
Polyp
cylindrical and sessile
Medusa
umbrella-shaped and free-living
General features of animals
Heterotrophy
Multicellularity
No cell walls
Active movement
Diversity of form
Diversity of habitat
Sexual reproduction
Embryonic development
Tissues
Evolution of animal body plan
Five key innovations in animal evolution
1. Symmetry
2. Tissues
3. Body cavity
4. Various patterns of embryonic development
5. Segmentation, or repeated body units
Bilateral symmetry advantages
Bilaterally Simental animals has two main advantages which are directional movement and cephalization, which is the evolution of a definite brain area
Differences in protostomes and deuterostomes
- Cleavage pattern of embryonic cells
* Protostomes = Spiral cleavage
* New cells form right or left of previous cells
* Deuterostomes = Radial cleavage
* New cells form on top of previous cells - Developmental fate of cells
* Protostomes = Determinate development
* Cell fate is determined early
* Deuterostomes = Indeterminate development
* Cell fate is not determined until after several divisions - Formation of the coelom
* Protostomes—cells move apart to form coelom
* Deuterostomes—groups of cells pouch off to form
coelom
Determinate vs indeterminate development
Determinate development
* Cell fate is determined early
Indeterminate development
* Cell fate is not determined until after several divisions
Sponge reproduction
Asexual
* Fragmentation
Sexual
* Choanocytes transform into sperm
* Sperm captured and passed to egg cell
* Development may occur within mother or in open water
* Larva is planktonic; will settle and transform into adult
How do animals obtain
energy?
Animals obtain their energy through hetrothotry.
• What is the first process a
newly formed zygote goes
through?
Cleavage, which is the process for like it’s dividing and it has that indentation separated
What types of symmetry are
found in animal bodies?
There are two types of symmetry, found animal, bodies, radial symmetry, and bilateral symmetry
Discuss body plans
There are three body plans
Acoelomates which is no body cavity, pseudocoelomates which is body cavity between the mesoderm and the endoderm,
Coelomates which is the body cavity entirely within the mesoderm
What are the advantages of
segmentation in animals?
1.Allows redundant organ systems in adults such as
occurs in the annelids
2.Allows more efficient and flexible movement because
each segment can move independently
What are the 2 branches of
Kingdom Animalia?
Parazoa: Animals lacking tissues (and therefore organs) and
a definite symmetry
Eumetazoa: Animals with definite shape and symmetry,
tissues; possibly organs and organ systems
Which cells in a sponge are
involved in water
movement, feeding, and
reproduction?
Choanocytes
What are the embryonic
layers in a Eumetazoan?
Inner endoderm forms the gastrodermis (digestive tissue)
- Outer ectoderm forms the epidermis and nervous system
- Middle mesoderm (only in bilateral animals) forms the
muscles
What is a nematocyst?
Cnidarians use nematocysts to capture prey
* Secreted within nematocyte
* Mechanism of discharge unknown
* Some carry venom
What type of body plan do
flatworms have?
Acoelomate
Discuss Schistosoma
reproduction
It depends on where you start, but geez, blood flutes live in the intestine or the liver well the blood vessels of the intestine or urinary bladder and then they get pooped out. Those eggs from the water have to be eaten by a snail if not, you might snail then it stops. From there, it goes into a fish and has to be certain type of fish and it goes to three stages and it will pop up in the muscles of that fish as they like and then these in the fish when the fish is like cooked or gonna be eaten. That is how these, blood flutes will enter into system and go into their intestine blood vessels
Why are tapeworms so
successful at reproducing?
They reproduce a lot like can produce a lot
How do rotifers eat?
They have a conspicuous ring of Celia at the interior end that is used for their local motion and sleeping food in their mouth
What is the difference between
the mantle and the shell of a
mollusk?
The difference between the two is that the shell is secreted from the mantle
Which class of mollusks has
terrestrial species?
Gastropoda
How are cephalopods different
from other mollusks?
Active marine predators has a closed secretary system
Brain size
Highly developed nervous
Which phylum of worms are
(mostly) segmented?
Annelids
What are chaetae?
Bristles of chitin found in most groups
Which worms are
ubiquitous?
Nematodes
Discuss human diseases
caused by nematodes
Enterobius vermicularis
Ascaris lumbricoides
Guinea worms
Filariasis
Which class of arthropods
has the most species?
Hexpoda
Discuss the features of
arthropods that make them
So successful
Segmentation
Exoskeleton
Jointed appendages
How do arthropods breathe?
Marines have gills
Terrestrial have tracheae
• Where does spider silk come
from?
Spinanet, on the on there like on the abdomen on there interiorly
Which stage of crustacean reproduction helped scientists realize barnacles are
crustaceans?
Nauplius
What are the 3 body regions of hexapodes?
Head
Thorax
Abdomen
Discuss insect life histories
Metamorphosis
What are the major differences between the two groups of myriapodes?
