Exam 2 Lab Flashcards
What is a mechanical advantage compared to a velocity advantage?
mechanical- exert more force or pressure at end of lever short distance to load and a longer distance to the force of the muscle. ratio of output versus input more output force given some small input force better at maximizing ratio.
velocity- ratio between force exerting on one end of lever how fast you can make a lever move with a particular lever move function of a ratio of output lever arm compared to input lever arm
What are the main forces acting on animals living a terrestrial life?
gravity- limbs holding you up against gravity
What are the main forces acting on animals living a aquatic life?
water pressure, buoyancy, drag, gravity
What are the main forces acting on animals living a aerial life?
drag and gravity
where are the major differences in design in the animals you observed? Think about the shape as a whole as well as head, appendages, trunk and tail
snakes- legless, scales, long body, small head, a lot of muscle, eyes forward, tail
turtles- have flipper
chickens- have two legs and two wings, small brains, feathers, scaled, heat feet, social organs, heat, can’t move eyes, tail
dogs- have four legs, fur, heat, eyes on front of head, tail
toad- warty skin, no scales, eyes sockets inside, eyes have side of head, no tail
Can you explain these differences in design from what you can see about how these animals move/ Remember what output force and output speed are inversely correlated, and that long output lever arms favor speed, whereas short lever arms favor force. consider that animal joints do not work in isolation, they work as series of internal levers linked like a chin; forearm for example. with linked levers you can change the position of the lever to optimize either speed or force. think about lifting a heavy weight, you position your levers to optimize either speed or force. think about lifting a heavy weight, you position your levers to the object in your hands is close to your body,you can’t move it very fast but you can move it. opposite to this is throwing a ball. here the object in your hand isn’t heavy so you can position your levers so the object in your hand is further away from your body. now you can move it at a much greater speed through a much greater range. can you try to use these concepts in your descriptions of movement?
dog has streamlined body with limbs lots of muscle in the back end for pushing off but not in the front.
toads- long limbs that are scrunched up for the use of jumping
rabbits- most of meat in back to push off for jumping purposes with scrunched up legs for recoil purposes
dog- long legs long lever=speed
rabbit=similar to toad
toad- one jumps crumpled up as spring with greater force and longer lever when jumping through air longer lever
fish-tail pushes body close to body
turtle- fins stay close to body built for strength to keep animal up than speed
snake-long moves back and forth speed
chicken mouth/jaw- very small and short lever meaning that they are very forceful to break things like the
can you identify one joint of each type (1,2 and 3 lever) in dog?
dog- type 1 neck and tail, knee- type 3, toes walking dog- type 2
Imagine being a fish and feeding by sucking in your prey into your mouth, vs. catching your prey with your teeth and jaws. what type o thing would you expect in their jaws in each case, one that maximized mechanical advantage or velocity advantage/ why?
fish mouth- velocity advantageous because the they are trying to be fast and surprise prey then want to have velocity advantage as it might be stronger than you
teeth- mechanical advantage having stronger force so prey doesn’t get and pull away
can you identify any convergences in general design from different modes of locomotion in these different groups?
fish- fin for speed
turtle- flippers for moving large amounts of water over them to swim better
general shape of animal limbs has bone numbers in the same place but different joints in different locations to accommodate needs like joint of wrist in toad vs. joint in bunny.
Feel the skin of these different animals. can you make some predictions about the function of the skin in these groups?
snakes- scales are for protection and helps them move as it is smooth and moves along with them
rabbit and dog both have a lot of fur
dog- less undercoat because heats up when running
chicken- feathers for warmth thin skin so feather provide most of protection
toads- rough thicker skin helps them keep more water.
What kind of fins do lampreys have?
2 dorsal fins
1 caudal fin
Which of the Creatures don’t have scales?
lamprey, sting ray, and catfish
Which animals have operculum?
catfish, sea robin, menhaden, and perch
Which animals have swim bladders?
catfish, sea robin, menhaden, perch
Which animals don’t have swim bladder?
skate, lamprey and sting ray
What kind of fins do sting ray have?
2 modified pectoral fins (big), 2 tiny pelvic fins, claspers, spine
What kind of fins do skates have?
pectoral fins (modified), 2 dorsal fins, a caudal fin, 2 pelvic fins, claspers
What kind of fins do catfish have?
1 dorsal + adipose fin (posterior to dorsal fin), 2 pectoral fins, 2 pelvic, 1 anal, 1 caudal
What kind of fins do sea robin have?
2 dorsal fins that are spiny and small, flat tail because of not speedy, 1 caudal fin,2 huge wing-like pectoral, anal fin
