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BI 150 Lecture Notes - Lecture 10: Notochord, Viviparity, Gonochorism

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crimsongoose556
8 Sep 2019
School
Oregon State University
Department
Biology
Course
BI 150
Professor
Felipe Barreto

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Document Summary

During early embryo development, the gut starts to form but do so from opposite ends in protosomes, and deuterostomes. In vertebrates, it develops into a series of mineralized articulated units called vertebrae. Instead of lungs, fish have gills which serve for gas exchange with the water. In front of the gills, there is a bony arch holding gill rakers. Gill rakers are involved in filter of suspension feeding. The length and separation of rakers depends on food type. Hagfish live in burrows in deep waters. Hagfish have mucous glands that produce lots of slime very quickly. Eat benthic animals (molluscs, fish, worms, crustaceans). Have been around for 450 million years. Main difference between sharks and rays: gill slits on side of head (sharks), and gill slits on ventral side (rays). Have denticles, which are tooth like scales. All sharks and rays are gonochoristic: meaning they have separate sexes. Males have claspers, which is for mating (delivering sperm to female oviduct).

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Related Questions

1. You discover a new animal that you suspent may be a sponge. You note it is neither diploblastic nor triploblastic. You should also note that it…

a. Has no spicules

b. Has no nerve or muscle tissue

c. Has no collar cells

d. Has no osculum

2. What is the best anatomical feature to look for to decide that a mollusk you found in the ocean is a true crab and not a horseshoe “crab?”

a. Presence of compound eyes

b. Claw-like mouthparts (chelicerae)

c. Two tagmata )cephalothorax and abdomen

d. Hard carapace

3. Imagine you are a paleontologist working in Ediacarian deposits and you find a new fossil species with a shell of some sort. This would probably make the “news” section of Science and Nature because….

a. Animals from edicarian have only bilateral symmetry

b. Animals from edicarian typically have a cephalization but no shells.

c. Animals from edicarian normally have no shells or any other hard parts.

d. Animals from eidc arian are only vertebrates.

4. While sampling marine plankton in a lab, a student encounters large numbers of fertilized eggs. The student rears some of the eggs in the laboratory for further study and finds that the blastopore becomes the mouth. The animal has torsion and eventually develops a radula. These eggs belong to a…

a. Clam

b. Squid

c. Chiton

d. Snail

True or false from answers in fill in the blank: if false what is the right answer?

____eumetazoa__________ phyla have bilateral symmetry and a mesoderm.

___protostomes______________ produce a mouth first during gastrulation and an anis*(can't use the actual word) later.

________deuterostome________ are chordates and echinoderms that form an oral opening second and an anal opening first.

Mollusk, such as the snail, primarily use ____sprial_______ holoblastic cleavage, in which the planes are not parallel or perpendicular to the animal vegetal axis, but instead at oblique angels. This leads to a spiral arrangement of the daughter blastomeres

A maternal effect is seen during cleavage. This means that the genotype of the developing snail is not influencing the direction of cleavage, but instead the genotype of the ____ovary__________ influences cleavage.

Individual C. elegans can produce both sperm and egg, making them ___hermaphrodites___________.

The first asymmetrical cleavage in rotational holoblastic cleavage produces an anterior found cell and a posterior ______PAR-2 and PAR-1__________

PAR proteins are involved in establishing cell polarity and the _____anterior and posterior regions_______________ in C. elegans

The __dorsal-ventral_________ axis is established in the division of the AB cell in C. elegans

Please write a sentence or twohypothesis for the first question, then describe your reasoning inparagraph form for each question. Points will be rewarded accordingto best use of key vocabulary words and proper description.thanks!


1)Write a one-sentencehypothesis before you write an answer.


Many aquatic invertebrates suchas squid, lobster, and crayfish are capable of very rapid muscleactivity and body movement. They respond to stimuli such as touchjust as rapidly as do terrestrial vertebrates. These capabilitiesof some, but certainly not all, aquatic invertebrate animals occureven though the animals lack myelination of their nerveaxons. Terrestrial animals have myelin covering many of theiraxons.Explain how these fast-moving invertebrates can have rapidresponses to stimuli and rapid onset of muscle movement in thecomplete absence of myelination of their axons. Include adiscussion of the structure of their axons that allows such rapidactivity and explain how it works.





2)Do Not Write aHypothesis.

How do aquaticand marine invertebrates that employ external fertilization avoidtwo major problems %u2013 fertilization of one egg by more than onesperm and fertilization of an egg by a sperm from a closely relatedbut different species.