Zoology from lecture 9/30 deuterstomes and echinodermata

Deuterostomes

Radical cleavage at 8 cell stage; the first opening (blastopore) is the anus; indeterminate cleavage

Radical cleavage

“line up”, a developmental pattern where successive cell divisions occur at 90-degree angles, producing tiers of cells stacked directly on top of one another

totipotent

they are not yet assigned a fixed developmental path, all genomes in disposal

Protostomes

spiral cleavage( not lined up), a major group of bilateral animals where the first opening in the embryonic gut (called the blastopore) traditionally develops into the mouth

what is the protostome development pathway

spiral cleavage

determinant cleavage

a pattern of early embryonic development where the developmental fate of each daughter cell (blastomere) is fixed very early ( each cell is pluripotent); the cell can only read part of its genome (there are many genes that are silenced)

indeterminate cleavage

an early embryonic cell division where each resulting cell keeps the potential to develop into a complete, separate organism

Which cleavage has Pluripotent cells

determinant (protosomes)

what is gastrolation

digestive tract is forming 1 opening blastopore (smaller cells), leading to atonal architecture

What are the characteristics of Echinodermata

spiny skin, water vascular system, adults have radial symmetry while larvae are bilateral, internal calcium carbonate skeletons

What are the classes in Echinodermata

Asteroidea, Crinoidea, Ophiuroidea, Echinoidea, Holothuroidea

What are the characteristics of Asteroidea

- Thick, broad arms and use of 2 feet “gliding along”

-aboral

-ambulacral groove

-has spines “spiky skin” and has pedicellariae

-attached to each canal is a tube foot

aboral

away from the mouth

ambulacral groove

2 tube feet, which is used to move

Which animal is in Asteroidea

starfish— ends of each arm has sensory tentacles

what are pedicellarine

small, wrench- or claw-shaped, pincer-like organs found on the external surface of sea stars, used for cleaning and defense

What animal are in Crinoidea

sea lillies

What are the characteristics of Crinoidea

-sexes separate with gonads that are masses of cells in the genital cavity arms and pinnules

- spaghetti-like arms

What is the water vascular system

Madreporite —> stone canal —> ring canal —> radial —> lateral canals —> tube feet on the ends

What is the function of each section in the water vascular system?

-Madreporite— A porous, sieve-like plate on the outer surface that lets seawater flow into the system.

-Stone Canal— A hard, tube-shaped structure that connects the madreporite to the ring canal.

-Ring Canal—A circular tube that surrounds the center of the animal.

- Radial Canals— Long tubes that branch out from the ring canal and run down each of the animal's arms or body sections.

-Tube Feet (Podia)— Small, stretchy suction-cup appendages connected to the radial canals that extend and retract using water pressure

What are the characteristics of Ophiuroidea

-Move using arms, not legs or suction

-Regeneration of the arm

-Tube feed without suction

-oral (no anus)

which animal is in Ophiuroidea

Brittle stars (will chop off an arm if bothered)

What are the characteristics of Echinoidea

-boniest one out af all echinodermata

-covered with epidermis and spines

-use spines for movement rather than tube feet (ossicles)

-no arms

-Aristotle lantern

Which animal is in Echinoidea

sea urchins/ heart urchins

What is Aristotle lantern

boney plates around mouth (mouth parts)

What is the reproduction and development Echinoidea

cell—> gastrula—> larva—> metamorphosis—>adult

What are the characteristics of Holothuroidea

fleshiest out of echinodermata

What animal is in Holothuroidea

sea cucumbers