Biological Design

Question 1

Study of biological design is….

Answer 1

the study of basic physics

Question 2

Animal morphology must obey….

Answer 2

the laws of physics

Question 3

Scaling

Answer 3

1. study of size and shape
2. requires more than making a small structure large in the same proportion
3. there is a disproportional change in different parts of the body as body size changes

Question 4

Size

Answer 4

1. physical forces that affect an animal are determined by its size
2. general rule

Question 5

General rule of size

Answer 5

1. the larger the animal the more important gravity is
2. the smaller the animal the more important are surface forces
   i. frictional drag
   ii. surface tension

Question 6

Basic rule between length, surface area, and volume

Answer 6

If shape is held constant then the relationships between length, surface area, and volume and mass all change

Question 7

Basic relationships between length, surface area and volume

Answer 7

1. surface is proportional to length2
2. volume is proportional to length3
3. those relationships hold for any shape that we expand while maintaining shape
4. examples
   i. increase a sphere from marble to soccer ball size
   ii. surface area increases 100 times
   iii. volume increases 1000 times

Question 8

Surface area

Answer 8

1. directly affects the rate many events occur [what melts faster an equal mass of ice cubes or block of ice]
2. biological functions
3. absolute amount of O2 and food ingested increase with size
4. as body size increases the O2 and food consumption per unit of body mass decreases
5. in a homeothermic animal, the rate of heat loss is related to body size
   i. due to surface to volume ratio
   ii. smaller individuals have larger surface areas and loose heat faster

Question 9

Surface area biological functions

Answer 9

1. rate of oxygen consumption and heat loss
2. importance of diffusion
3. rate of digestion
4. locomotive patterns

Question 10

Volume and mass

Answer 10

1. body mass is directly proportional to body volume
2. Mass is proportional to length3
3. in terrestrial organisms, with limbs, the mass is carried by the legs
   i. cross sectional area of the limbs also increases disproportionally
   ii. cross sectional area of the bones increases in proportion to mass and volume and not length

Question 11

Shape

Answer 11

1. maintain function
2. allometry
3. positive allometry occurs when the y variable grows faster than the x variable
4. Negative allometry occurs when the y variable grows slower than the x variable
5. isometry occurs when the proportions between two characteristics remain constant
   
   • shape remains constant with increasing size

Question 12

Shape’s maintain function:

Answer 12

1. animal’s design has to be altered

2. because length, surface area and volume all change at different rates

Question 13

Allometry

Answer 13

study of changes in shape

 i. change in shape can be expressed in the form y=ax^b
 ii. equation describes how different body parts change relative to each other

Question 14

biomechanics

Answer 14

application of engineering principles to biological design

Question 15

principles of biomechanics

Answer 15

1. basic quantities
   i. length concept of distance
   ii. time concept of flow of events
   iii. force the effects of one body acting on another
   iv. mass the property of matter
   - weight is a measure of force operating on mass
   - objects of different mass take different amounts of force to move
2. units are conventions, standard of measurement that are used to describe length, time and mass
3. derived quantities which describe the motion of bodies
   i. velocity
   ii. acceleration

Question 16

velocity

Answer 16

rate of change of an objects position, miles/hour

Question 17

acceleration

Answer 17

rate of change of an objects velocity, miles/hour/hour

Question 18

Basic Force Laws

Answer 18

1. First Law of Inertia
2. Second Law of Motion
3. Third Law of Action and Reaction

Question 19

First Law of Inertia

Answer 19

1. tendency of a body to resist a change in its state of motion
2. an object will continue in its state of rest or in a uniform path of motion until a new force acts on it to set it in motion or change the direction of its motion
3. takes force to move something or change its direction

Question 20

Second Law of Motion

Answer 20

1. change in an objects motion is proportional to the force acting on it
2. force=mass x acceleration F=ma

Question 21

Third Law of Action and Reaction

Answer 21

for two objects in contact there is for each action an opposite and equal reaction

Question 22

Free bodies and forces

Answer 22

1. diagrams that show each isolated part of a system and the forces acting on each part
2. permits the study of parts of a complex system
3. can divide the mechanics into two conditions
   i. static equilibrium
   ii. dynamic equilibrium

Question 23

static equilibrium

Answer 23

conditions when all forces acting on an object are balanced and equal

Question 24

dynamic equilibrium

Answer 24

when forces acting on an object are not equal or unbalanced; motion is imparted

Question 25

Torques and Levers

Answer 25

1. skeletal and muscle systems of animals work together to generate movement
2. muscles generate force; skeleton applies force
3. study this using torques and levers
4. parts of a lever system
   i. lever arm-length is the distance from the weight to the furlerum
   ii. fulcrum is the pivot point
   iii. when a fulcrum is centered and weight on both lever arms is equal the system is balanced
   iv. shorten one arm, more weight has to be added to that side to keep it balanced
5. torque
   i. in-torque
   ii. out-torque
6. to generate more force, shorten the out lever arm and lengthen the in lever arm
7. to generate more speed, you shorten the in lever arm and lengthen the out lever arm
8. examples
   i. digger
   ii. runner
   iii. muscles can modify this basic pattern slightly

Question 26

in-torque

Answer 26

torque of force generated by the lever arm that is closest to the fulcrum [origin of force]

Question 27

out-torque

Answer 27

torque of force generated by lever arm that is furthest from the fulcrum