Embryology

Embryology

Animal tree – Zygote → Blastula → Gastrulation



Cell embryology slide.

 

Protostome - initial opening (blastopore) develops into the mouth.

Deuterstome - initial opening develops into the anus.

Archenteron - primitive digestive tract.

Blastopore - opening to the archenteron.

Endoderm - outer layer of the early embryo.

Ectoderm - inner layer of the early embryo.

Chordata - deuterstome

Echinodermata - deuterstome

Arthropoda - protostome

Mollusca - protostome

Annelida - protostome

Nemotada - protostome

Platyhelminthes - protostome

Cnideria

Porifera

Landlubber Grasshopper

ARTHROPODS

Classes: Insecta, Arachnida, Crustacea.

Lubber grasshopper cut for learning.

Cephalization: nervous tissue becomes concentrated at one side of the organism (at the head), this can help distinguish between the anterior and posterior of an animal.

Appendage specialization: hinge joint.

Movement: legs for hopping and jumping, wings for flying.

Nutrition: herbivores that feed mainly on leaves

Dissected landlubber grasshopper.

 


End of the ovary of the female lubber grasshopper.

 



Full ovary of our female lubber grasshopper.       



 

      Our female lubber grasshopper's rectum.




Grasshopper tail end (anus, ovipositer, vagina).

  

 



Hydra

HYDRA

PHYLUM CNIDERIA
PHYLUM COELENTERATA

(coel meaning 'hollow' and enteron meaning 'gut')

Hydra through the microscope.

Morphology:

v  one opening (mouth)

v  hollow body

v  main cavity of the hydra's body is the digestive cavity

v  consists of two layers: ectoderm (outer – protective epithelium) and endoderm (inner – primarily a digestive epithelium)

Habitat: Hydras live in freswater lakes, ponds and streams. They attatch to rocks and water plants with a sticky secretion from disklike base.
Movement/Locomotion: 

v  gliding on the base due to a creeping ameboid movement of basal cells.

v  bending over and attaching to the substrate with the mouth and tentacles and releasing the foot (which usually provides attachment), then the body bends over and makes a new place of attachment.

Eating: Do not chase prey but poisons it. It leaves its tentacles trailing and when they are brushed, send out a shower of poisonous numbing thread capsules (weapons that arm the body).

Earthworm

WORMS

3 Phyla: Annelida, Platyhelminthes, Nemotada

Our earthworm, cut and ready to be learned from.

Keely and Tyler hard at work.

Movement: muscles contract and relax along the worms body, ‘setae’ (tiny hairs covering the worm’s body) help to anchor the worm.

Morphology:

v  One end has oral opening, the other has anal opening.

v  Breathes through epidermis (skin, outer layer).

v  Closed circulatory system - blood is confined to blood vessels and is circulated to get maximum use.

v  Simple brain with nerve cord.

Embryology: Female egg fertilization, then the egg goes through mitosis to create a blastula. The blastula then begins to fold inwards forming the oral opening, it’s anal opening is formed later.
*Annelidas vs. Chordata – different opening forms in the blastula.

 Video - Locations of the parts of mine and Spencer's earthworm.

Invertebrates

Jointed Appendages 

Where the bones that make up the appendage have contacts between them.
Eg. Antenna, Mouth Parts, Claws, Legs

Arthropoda "Jointed Legs"

Various appendages of arthropods have specialized structure to adapt them to a particular function (increases efficiency but sacrifices versatility). Jointed appendages, originally for locomotion, have been modified for a great variety of functions, even in the same animal. 

Typical arthropod: a segmented, coelomate invertebrate animal with bilateral symmetry, an exoskeleton and jointed structures called appendages.

What is an Animal?

What are the characteristics of an animal cell?

• Animal cells differentiate and carry out different functions
• Animals have specialized cells.

What are the characteristics that all animals share?

• All animals are eukaryotes (contain membrane-bound organelles).
• All animals are heterotrophic.
• All animals are multi-cellular.
• Animals obtain food.
• Animals digest food.

What are invertebrates? An invertebrate is an animal that does not have a backbone.

• Many invertebrates have exoskeletons (a hard covering on the outside of the body that provides support) include crabs, spiders, grasshoppers, dragonflies and beetles.
• Invertebrates such as sea urchins and sea stars have an endoskeleton (internal skeleton).     
  
  
  What are vertebrates? A vertebrate is an animal with an endoskeleton and backbone. Examples: fishes, amphibians, reptiles, birds and mammals.

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