Bio Exam 3 Flashcards
Forces
Lift ^
Thrust >
Drag <
Gravity v
Movement underwater
Yaw
Roll
Pitch
How do fish generate lift?
Buoyancy with swim bladder
How does gas get into swim bladder?
Arteries and veins form net around swim bladder
- Blood acidifies
- Oxygen released from blood
- Moves into bladder
Bladder inflates? deflates?
Inflate: gain buoyancy
Deflate: lose buoyancy
Problem with buoyancy
Center of buoyancy below center of mass
Fish will flip over
Need additional help from fins
Types of fins
Pectoral (pec- side) Pelvic Anal Dorsal (top) Caudal (tail)
Dorsal Views? Which is best?
Looking down on top of fish.
Ovate
Elongate
Fusiform
Needle-like (the best)
Cross-section? Which is best?
Laterally compressed
Circular (the best)
Triangular or sub-circular
Dorsoventrally depressed
What other factors affect body type?
Habitat
Feeding
Predator lifestyle
How do fish generate thrust?
Involves undulations of body
Differs in how much of body undulates
Types of undulations/ways to generate thrust?
Eel-Like
Mackerel-Like
Eel-like swimming
Most of body undulates
Dorsal fin extends down most of the body
Mackerel-like swimming
Only rear of body undulates
Stiff body
Use muscles
Large symmetrical tail
Tail has to generate a lot of thrust since only ⅓ of the body is “swimming”
Tail shape
High height to depth ratio:
Fast swimming
Good maneuvering
Low height to depth ratio:
Slower swimming
More drag
Types of fish muscle
White muscle
Red muscle
The entire muscle is essentially activated at once
Muscles are activated sequentially from head to tail
White Muscle
Fast
Used in burst
Small # of blood vessels
Most of body mass
Red Muscle
Slow
Endurance
Large # of blood vessels
Small part of body
Fish Fins and movement
Stabilizing, turning, propulsion
Can turn over like insect wings
Very flexible and moveable
-Can hover, turn, and brake
Fin rays
Attached to muscles
Allows fine motor control
Feeding in bluegill
Fish create a vacuum in mouth to suck in food
Boxfish
Live on reefs
Has fused bony plates along body
Move mainly by using pectoral fins
Small: 3-6 inches
Daimler-Chrysler’s bionic car/Chevy Bolt
“Box fish car” Mimic box shape Mimic hexagon internal structure Extremely aerodynamic and stable Reduces drag by up to 65% Up to 70 miles per gallon (mpg)
Underwater autonomous vehicles (UAVs)
Swim in water and collect data
Temperature, salinity, currents
Used to map ocean floor
Ex. Robotic fish
Shark differences from fish?
Skeleton is made out of cartilage
Do not have a swim bladder
Fins are stiffer
Scales are like little teeth
How do sharks remain buoyant?
Don’t have swim bladder
1. Have extremely large bladder
25% of body weight
Stores oil
- Pectoral fins provide lift (similar to wings)
- Have unequal tail fin
Upper lobe larger
Generates force down - Use body posturing
Even with adaptations, shark will sink if not moving
Most sharks continually keep moving (some rest on ocean floor)
Shark scales vs fish scales
Bony fishes: fairly smooth
Sharks: rough and pointed
Shark Scales
- Pointed towards tail
- Keel in the middle and at sides
- Forms grooves for water
Reduces friction
Makes it harder for other organisms to stick on scales
Sharks don’t have a slime coat
Fastskin suit
Reduces friction
Using shark scales as a way to modify
Scientists questioned if the suit actually reduced friction and it didn’t → taken off shelves
Major problem for fish and ships is biofouling
Small organisms grow on surface, just like on whales (barnacles). Can’t grow on scales
Solution for biofouling
Ships use heavy metal in the paint (like copper)
Except when the paint chips, it’ll fall into the ocean and cause pollution
They realized sharks don’t have biofouling
Gator Sharkote
Makes it harder for other organisms to stick on scales
Algae can’t attach well to this surface
Echolocation
Location of Objects by reflected sound
Sonar
Echolocation underwater
Animals that use echolocation
Most bats
Dolphins
Toothed whales (Orca)
Vagrant Shrew
Primary uses of Echolocation
- Primarily used to find food
- Used for orientation in environment
- Exploring surroundings (Shrews)
- Navigating in caves (bird)
Used when vision is not sufficient
How echolocation works
Sound waves travel from sender
Hit object and reflect to sender
Time it takes for sound to come back is used to measure distance
Directionality
Directionality due to having two receivers
Sound Reaches one ear sooner than another
Movement away or towards determined by Doppler effect
Doppler Shifts
Time between waves changes
More time when moving away
Less time when moving towards
Like Car horn moving towards/away
Types of sounds produced by bats
Constant Frequency (CF)
Frequency modulation (FM)
Constant Frequency (CF)
Same frequency produced per unit time
Detecting targets and Doppler shifts
Frequency modulation (FM)
Downward sweep of frequencies
Honing in on distance to target
How does sound production in bats occur
Produced by larynx (Voice Box)
Some species emit through mouth or the nose
Dolphin Skull
Brain case Eye socket Upper jaw Lower jaw (BIGGER than upper) Contains same ear bones as other mammals
Mammalian Ear Anatomy
- Outer Ear
Captures sound and directs to rest of ear - Middle Ear
Series of bones that transfer vibration to inner ear structures - Inner Ear
Takes vibrations and translates them into nerve impulses
How do dolphins hear?
Dolphins evolved a different outer ear
- Lower Jaw is the “outer ear”
- Hollow and fat-filled
- Carries vibrations to middle ear
Auditory bulla for dolphins
Dolphins isolated inner ear from rest of skull
Inner Ear encased in bone
Connected to skull by fibrous tissue
Connection between lower jaw and auditory bulla
How do dolphins produce sound?
Still requires the use of air
Nostrils moved to top of head
Series of air sacs associated with blowhole
- Air passes between sacs
- Phonic Lips control air movement
- Opening/closing causes clicks
Melon
Acoustic lens that focuses sound
Made of low density fats
Surrounded by blood vessels
-Influence fat composition
May have other functions
-Like buoyancy
Skull Anatomy of Odontocete Whale
Sound generator
Monkey Lips/Dorsal Bursa Complex (MLDB)
Monkey lips, anterior and posterior bursae
Uses of echolocation by toothed whales
- Foraging for Food**
- Avoidance of predators**
- Awareness of environment**
- Communication avenue
- Social behavior
- Parental Care
The BatHat
Hat designed to aid vision impaired
Consists of ultrasound sender and receiver
Vibrating motors to alert user
Hardware
Computing Basics
- CPU
- Input Devices
- Output Devices
- Storage devices
- Memory (RAM)
Binary logic
0=False
1=True
Switches
electrical equivalents of 0 and 1 (2 states)
Off is 0
On is 1
Combine and expand switches
Complex states with 2 switches (4 states)
1st state- 0 and 0
2nd state- 0 and 1
3rd state- 1 and 0
4th state- 1 and 1
NOT, AND, NAND
NOT (Switch to other state)
0 to 1
1 to 0
AND (Combine two states) 0 0 = 0 0 1 = 0 1 0 = 0 1 1 = 1
NAND (Opposite of AND)
Transistors
More transistors = more memory and speed
Pack close together as possible
Decrease travel time of electrical currents
232 million transistors in CPU
Silicon-based Transistors
Control flow of electrons w/ gate
Pulls electrons up from P-Layer
Completes Circuits
Moore’s Law
of transistors doubles every two years
Stored-program computers
Von Neumann Architecture
Instructions contained in computer (Like calculator)
CPU and hard drive
Same computer can do many things
- Fixed-program computer
- Limited Utility
Major constraint of stored-program computers
Von Neumann bottleneck
Limited data transfer from memory to CPU
CPU can work faster than info can get there
-Lag time decreases efficiency
Increases in hard drive size and processor speed don’t solve problem
Brain Basics
Centralized structure of nervous tissue
Divided into sections with different functions
Conscious and subconscious controls mostly separate
Cerebrum
80% of brain
10,000 miles of fibers per square inch
Two hemispheres connected by bridge of tissue
-250 million nerves in bridge
Storage, conscious thought, thinking, speech, motor control
Hippocampus
Working memory to long-term (may take weeks)
Compares info to stored experiences
-Making meaning
Amygdala
Emotional responses as learning is stored from working memory to long-term
I fear Amy
Neurons
Functional units of nervous system
100 billion neurons in human body
2/10ths second to travel from head to toe
Connections translate into learning
- Useful connections permanent
- Others pruned away
Processing
- Senses
- Perceptual Register
- Short-Term Memory
- Working memory
Senses
Collect about 40,000 bits per second
Perceptual Register
Filters information in 1/1000th sec
Strength, nature, importance
Short-Term Memory
Holds data for about 30 sec
More important data diminishes processing of less important
Working memory
Continuous processing occurs
10-20 min spent on one thing
If unresolved, items can last for days
Neuron Structure
Connect to other neurons via synapses
- Dendrites (Receivers)
- Axon Terminals (Transmitters)
- Schwann’s Cells (Make Myelin)
- Axon (Conducting fiber)
- Myelin sheath (Insulating fatty layer that speeds transmission)
- Node of Ranvier
- Nucleus
- Cell body
Brain vs. Computer
- Computers are not brains
- Brains are unpredictable, computing is about control
- Brains are not programmable like computers
- Brains compute physically, not logically/symbolically
- Brains are made of carbon not silicon
- Brains work in parallel, computers are linear
- Neurons are sophisticated computers, not switches
- Brains evolve by side effects, computers can’t
Neurons are sophisticated computers, not switches
Neuron integrates many inputs
Compares them in detail
Adjusts the strength of the output
Jigsaw Computing
Biological systems ‘feel’ the way to answers
Use the 3D shapes to identify molecules
Computers not good at picking out fuzzy images
Use of self-assembly to recognize patterns
Use the 3D shapes to identify molecules
Substrate enters the active site of an enzyme
Enzyme changes shape as substrate binds
Enzyme + substrate à products
Products leaves active site of enzyme
Computers not good at picking out fuzzy images
Average the input for each pixel
Use of self-assembly to recognize patterns
Take an image
Project onto surface containing light receptors
Each receptor produces unique molecule
Molecules fall into solution and self-assembly
Measure concentrations of molecules to get pattern
DNA Computing
Use self-assembly of DNA to solve problems
DNA composed of
Four components (nucleotides) Adenine Cytosine Guanine Thymine
Nucleotides are complementary
Self connect via Hydrogen bonding
Putting strands into solution leads to pairing
Each piece of information can be given unique sequence
Brute Force Computing
Try every possible solution
Need to have lots of computers to do this
Each piece of DNA is like a processor
Electrical Charge Storage
Magnetic head moves over platter
Reads and changes charges on surface
Hard drive
Platter
Copper wire
Actuator arm
Light for Bio-Computing
Use light to retrieve information
Ridges- bumps
Land- between bumps
Photoelectrical cells detect light intensity
Ridge= weak signal, 0’s Land= strong signal, 1’s
Bacteriorhodopsin
Light sensing pigment
Switches shape when hit by light
Green light = folds up
Red light unfolds
Attach bacteriorhodopsin molecules to membrane
Use laser to flip molecules
Store binary data just like a hard drive
Artificial Neuron
Weighted goes into Input
Input goes to Threshold Activation
Then goes to Output
Input, Middle, Output Layer
Input Layer»_space;> Middle Layer (artificial neurons)»_space;> Output layer (prediction)
Keep doing it over and over until prediction matches whatever you’re looking for
What is a robot?
A machine that can sense environment and respond
Agent»_space;» Effectors»_space;» Environment
Environment»_space;» Sensors»_space;» Agent
Effectors
Convert software commands into motion
Usually electric motor or hydraulic/air cylinders
Two main types:
Locomotion
Manipulation
Locomotion
Many kinds of effectors can be used to move a robot
Usual types:
- Legs (for walking/crawling/climbing/jumping/hopping)
- Wheels (for rolling)
- Arms (for swinging/crawling/climbing)
- Flippers (for swimming)
Why is wheeled locomotion easier?
Stable
Can be fast
Consume less energy
Less moving parts
Wheels vary in shape, tire patterns, can even be on tracks
Problems with wheeled locomotion?
Doesn’t handle complex environments well
Can’t climb over obstacles higher than wheel radius
Popular design of wheeled locomotion?
Two steerable wheels and caster
Good for arbitrary routes
Routes for locomotion
Concerned with getting to particular location
Following a particular route
Preferably without stopping and starting
-Very hard to do this
Arbitrary routes
Use planning to compute optimal routes
Relies on ability to search for routes
Integrate neural nets
Degrees of freedom
In what directions can robot move
Wheeled robots/car have low degrees of freedom
-Left, right, forward
Our arm
-6 degrees of freedom
Legs
Better handling of rough terrain
Use of isolated footholds
-Optimize support and traction like a ladder
Active suspension
- Decouples path of body from path of feet
- Payload free to travel despite terrain
Static
Can stand still and not fall over Need enough contact points for support Legged animals have to learn to be statically stable -Learn as babies -Always actively adjusting
Static Stability
Examine sequence of support patterns provided by quadruped walking
Body and legs move to keep center of gravity within the polygon defined by feet
- Like AT-AT walkers
- Polygon of support
- Lifting one leg, having three legs make triangle
Assumption of static gait
Weight of the leg is negligible compare to that of the body
- Thus, the center of gravity is not affected by the leg swing
- The conventional static gait is designed to maintain the center of gravity inside the support polygon
- Polygon is outlined by support legsʼ positions
Dynamic Stability
Allows robot to be stable moving
- One-legged hopping robots are dynamically stable
- Hop in one place or to a destination
- But can’t stop or stand
Tripod Gait
6 legs are popular because they have a stable walking gait
If 3 legs move at a time, alternating tripod gait
A rectangular 6 legged robot can lift 3 legs to move, and still retain static stability
Alternating tripod gait
Biologically common walking pattern for animals with 6+ legs
Characteristics:
- One middle leg on one side & two non-adjacent legs on the other side lift
- 3 support legs remain and provide static stability
Manipulation
Used to move materials or parts
Can manipulate large to micro objects
Designed based on jointed limbs
Human arm usual model
Manipulators
Two general parts
1. Arm/body
-Used to move materials
within area
- Wrist
- Used to orient material
Bay Scallop
Has eyes that sense changes in light
Slime Mold
Starts as single cell then groups into mass of cells
Star-nosed mole
Nose has tentacles to detect food
World’s fastest eater- 230 milliseconds
Giant Water Bug
Bug that can eat small fish and frogs
Males carry eggs around on back
Tragus
Prominence on inner side of external ear
In front of and partly closing the passage to organs of hearing
Sound detection where?
Extra Large Outer Ears
- Function like antennae
- Can be directed toward sounds
- Need to deal with vertical detection
