Lab 9 Flashcards
Only one plane of bisection produces left and right mirror image halves
Bilaterally symmetric
A characteristic of bilateral organisms is that the bost is polarized along two perpendicular axes the _____ axis and the ____ axis
anterior-posterior (head-tail)
dorsal-ventral (back-belly)
Flatworms are in phylum
Platyhelmithes
Roundworms are in phylum
Nematoda
Segmented worms are in phylum
Annelida
The tissue that gives rise to the covering of the animal
ectoderm
Gives tise to the lining of the digestive tract
endoderm
Forms the muscles and most other organs between the gut and outer covering
Mesoderm
Flatworms lack an internal body cavity, apart from an incomplete digestive tract and as such are referred to as
acoelomates
Roundworms have a body cavity located between the mesoderm and endoderm. This type of body cavity is referred to as
pseudocoel
Annelids have a body cavity that develops entirely within the mesodermal layer. Their body cavity is referred to as a
true coelom
Animals with a true coelom including mollusks, echinoderms, arthropods, and chordates are called
coelomates
The cavity in the endoderm is called the
alimentary canal
A body cavity can also serve as a ___ particularly in soft-bodied worms like nematodes and annelids.
hydrostatic skeleton
Uses muscular contractions to displace fluid within a cavity, thereby exerting force and changing the shape of the cavity
hydrostatic skeleton
Flatworms exhibit ___ and a level of complexity that exceeds that found in Radiata and Porifera
cephalization
Flatworms lack a circulatory system and thus are ____ with respect to transportation of nutrients and oxygen
diffusion-limited
Individuals in most species of flatworms are ___ they have male and female structures
monoecious/hermaphroditic
Many flatworms are ___ living within the bodies of other animals. Some examples mentioned ___
Parasitic
FLukes and tapeworms
____ flatworms feed on small animal and organic debris such as class Turbellaria
Free-living
Free living flatworms found in marine environments
Turbellarians
A flatworm commonly known as planaria, is found in freshwater, what we looked at in lab.
Dugesia
The head of the Dugesia flatworm has lateral lobes and light-sensitive ____
eyespots
How does the Dugesia flatworm move
cilia on their ventral surface and muscle contractions
Also known as flukes, parasitize vertebrates, including humans. Can exist as endoparasites or ectoparasites
Trematodes
The life cycle of Trematodes is complex. The first intermediate host is typically a ____ If a second intermediate host is involved it is usually a(n) _____. A ___ is always the final or definitive host.
Snail
Arthropod or fish
vertebrate
General life cycle of Trematoda
Zygote, miracidium, sporocyst, redia, cercaria, metacercaria, adult
Fasciola commonly known as ____ sucks blood a, mucus, and cells from infected sheep and cattle.
Sheep liver fluke
The primary jobs of any parasite is
to take up nutrients and produce tons of eggs
O. sinensis Infection in humans may result from consumption of raw or undercooked fish. Heavy infection may cause cirrhosis of the liver and death
Oriental liver fluke
Schistosoma aka ____ inhabits the intestinal veins and other organs of their host causing enlargement of the spleen, liver, and bladder as well as bleeding ulcers and an overall nutrient deficiency.
Human blood fluke
The most evolutionarily derived flatworm taxa. Also known as tapeworms.
Class Cestoda
Phylum platyhelminthes,
The ribbon-like body of tapeworms is divided into an anterior ____ which has hooks and suckers for attachment, a narrow neck where growth initiates, and a chain of serially repeating segments called ____
scolex
proglottids
The most abundant and diverse animal taxa.
Nematodes
The nematode body plan is simple. A body cavity known as a ___ occupies the space between the body wall musculature and the gut
pseudocoel
Most nematodes move ___ and ___ using sinuous, eel-like undulations produced by alternating contractions of dorsal and ventral longitudinal muscles.
forward and backward
Turbatrix, aka ____ is a free living nematode that feeds on bacteria and yeast in dead organic matter. Able to live in acidic environments
The vinegar eel
Ascaris aka ____ infects humans and is spread through feces. Moderate infections lead to malnutrition while heavy infections may result in intestinal blockages.
Intestinal ROundworm (dissected in lab)
The smallest nematode parasites of humans, rodents, and other carnivorous animals. Causes the disease trichinosis. Lives in the host’s intestinal wall, is viviarousand its juveniles are carried by the blood to skeletal muscles where they encyst.
Trichinella spiralis
Other parasitic nematodes include the ___ Necator (causes anemia), and the ___ Enterobius (found in the intestines of children).
Hookworms
Pinworms
____ inhabit the lymph glands and other tissues of vertebrates usually birds and mammals.
Filarial worms
____ can cause elephantiasis
Wuchereria
Dirofilaria aka ___ infects the heart and pulmonary tissues of dogs
Heart worm
Diversification in annelids evolved in conjunction with ___ the construction of a body from a series of modular sections
Segmentation
An advantage of a segmented body is that the development and function of individual units an be more ___
precisely controlled
Segmentation also allows for an improved ___ because the coelomic cavity is divided into fluid-filled compartments that can be controlled
hydrostatic skeleton
To move annelids contract ___ and _____
circular muscles and longitudinal muscles
Annelids also have a ___ that carries blood from one segment to another
closed circulatory system
In Annelids a ___ connects ganglia in each segment with one another and with the regions that are specialized for different functions
ventral nerve cord
Class ___ exhibit a stunning array of forms. Found exclusively in marine environments
Polychaeta
A defining feature polychaetes is that each segment of the body has a pair of ____
Parapodia
Fleshy lateral outgrowths of the body wall that are typically used for locomotion
Parapodia
Projecting from the parapodia are many small bristles called ___ which serve to anchor the animal during locomotion
setae
The class containing earthworms and leeches
Class Clitellata
Contribute to the decomposition of organic matter and the aeration and enrichment of soil
Earthworm
Oligochaeta
The crop of the Earthworm is used for ___ the gizzard is used for grinding
food storage
The ___ is a series of swollen segments used for reproduction
clittelum
Sperm of the Oligochaetes is produced in ____ and accepted in
seminal vesicles
seminal receptacles
Hirudinea aka ___ are blood suckers but also feed on other small invertebrates. Is dorsoventrally flat. Secretes anticoagulants. Have a clitellum that is only obvious during reproduction
Leeches
