Invertebrates; 1100 Flashcards
Questions
Invertebrates are animals without what?
backbones
What do simple invertebrates lack?
digestive, respiratory, and nervous systems
What has greatly reduced the once vast sponge fields?
sea pollution, sponge-killing diseases, and over-harvesting
What are sponges when they don’t move and attach themselves to rocks and other objects on the ocean floor?
sessile
What sponge is the most common and have skeletons made of spongin?
Demosponges
What are the only class of cells in sponges?
Epithelial cells
What cells differentiate into other cells specialized for specific functions?
Epithelial cells
What cells line the central cavity of a sponge and trap and digest food particles?
Collar cells
What fibers make up a sponge’s skeleton?
spicules
What 2 reproductive cells during sexual reproduction unite to produce a new offspring?
gametes
What single-cell organism is produced when a sperm fertilizes an ovum?
a zygote
What’s it called when sponges and most cnidarians are able to produce both male and female gametes?
hermaphroditic
Since sponges do not possess reproductive organs what can transform into sperm?
amoebocytes
Since sponges do not posses reproductive organs what can transform into ova?
collar cells
What reproduction does not involve male and female gametes?
Asexual reproduction
What are two methods of asexual reproduction used by sponges?
budding and regeneration
What is a hydra?
a cnidarian
How does a hydra have the ability to move?
by turning somersaults
What is a polyp?
a hollow, tube-shaped stalk with a mouth at its top that is surrounded by tentacles
What is a polyps mouth surrounded by?
tentacles
How do cnidarian polyps reproduce sexualy?
by producing male and female gametes in specialized epithelial cells in the ectoderm
How do cnidarian polyps reproduce asexually?
by budding and regeneration
What happens when a coral polyp buds?
the offspring remains attached to the parent through a series of canals that connect their gastrovascular cavities
What do new coral polyps attach to?
the dead skeletons of older polyps
What does the life cycle of a common jellyfish involve?
a sessile polyp stage and a free-swimming medusa stage
What is a Portuguese -man-of-war?
a colony of interconnected, specialized polyps that preform special task
What is the shell made of?
hard minerals mixed with fibers of protein
What is the purpose of the shell?
to protect the delicate skin and internal organs
Where is the gill located in an aquatic snail?
just beneath the mantle in the anterior portion is a chamber called the mantle cavity
What is a snail’s main source of locomotion?
its foot
What is a snails foot like?
it is flat, broad, and muscular and contains numerous mucus glands
How do most aquatic snails get oxygen?
oxygen from the water passes through the tiny membrane of the gill and enter tiny blood vessels
What kind of circulatory system does a snail have?
an open circulatory system
What happens in the snail’s open circulatory system?
blood leaves the heart and flows through the arteries, but it does not flow directly back to the heart
Where is oxygenated blood pumped from?
oxygenated blood is pumped from the ventricle of the snail’s heart into the dorsal aorta
Where does oxygenated blood go from the dorsal aorta?
it supplies blood to the visceral mass
Where does oxygenated blood go from the visceral mass?
into the ventral aorta
Where does oxygenated blood go from the ventral aorta?
it then supplies blood to the snail’s head and foot
Where does deoxygenated blood flow from?
the upper cavity
Where does the deoxygenated blood go from the upper cavity?
into the kidney where it is filtered
Where does the deoxygenated blood go from the kidney?
into the lower cavity
Where does the deoxygenated blood go from the lower cavity?
through a vein into the gill where it becomes oxygenated
Where does the now oxygenated blood go from the gill?
it flows back to the atrium of the snail’s heart
What are the tentacles on a snail’s head covered with?
receptors that detect chemicals, pressure changes, or light
What are clams, oysters, scallops, mussels, and shipworms?
bivalves which are mollusks with two hinged shells
How are the two shells of a bivalve joined?
along one edge by a hinge made of a strong, flexible ligament
What are hinge teeth?
a row of denticles that keep the two valves aligned so they can close securely
What is nacre?
the flat crystals that the inner layer of some bivalve shells are made of, sometimes called mother-of-pearl
What does a clam use its foot for?
digging not crawling
What does the incurrent siphon do?
draws water into the bivalve’s mantle cavity
What does the excurrent siphon do?
pumps water and waste material out
What do the bivalve’s gills do?
exchange oxygen and carbon dioxide and collect plankton for the mollusk to eat
What takes place in the stomach?
mechanical and chemical digestion
What type of circulatory system does the bivalve have?
open
What type of heart does a bivalve have?
a three-chambered heart and more blood vessels then a gastropod
What does the bivalves kidney do?
filters out liquid waste out of the blood
What does a bivalves nervous system consist of?
two pairs of cords, three pairs of ganglia, and sensory receptors lining the mantle cavity
What are ways cephalopods can move?
by walking, swimming, or it can use jet propulsion
How can a cephalopod use jet propulsion to move?
by rapidly forcing water out through its siphon
What kind of circulatory system do cephalopods have?
closed circulatory systems
Why does a cephalopod have a closed circulatory system?
because they have higher metabolisms than other mollusks
What color is a cephalopod’s blood when oxygenated?
blue
What color is a cephalopod’s blood when deoxygenated?
clear
Why is a cephalopod’s blood clear when deoxygenated?
because of the protein hemocyanin
How many hearts do cephalopods have?
3
What type of hearts do cephalopods have?
a systemic and 2 gill hearts
What does a cephalopods systemic heart do?
pumps oxygenated blood to the aorta
What does a cephalopod’s gill hearts do?
pumps deoxygenated blood through the gills
What happens in the cephalopods digestive system?
food passes from the mouth through the esophagus into the crop, where chemical digestion takes place
Where does nutrients pass?
into surrounding blood vessels through the walls of cecum
What does a cephalopods nervous system include?
ganglia throughout its body and a brain with specialized areas for senses, memory, and learning
