Biol 441 exam 3

Question 1

Tension

Scalar? Vector? or x order tensor?

Answer 1

2nd order tensor

Question 2

Strain

what is it?

Answer 2

the percentage of a material that has lengthened or shortened in response to stress applied to it

Question 3

Strain

Scalar? Vector? or x order tensor?

Answer 3

2nd order tensor

Question 4

Elastic resistance

Scalar? Vector? or x order tensor?

Answer 4

4th order tensor

Question 5

Elastic resistance

what is it?

Answer 5

ratio of stress to strain

Question 6

Stress

what is it?

Answer 6

mechanical force per cross sectional area (f/m^2)

Question 7

Young’s modulus

what is it? what is it large in? small in?

Answer 7

the slope of the curve of stress vs. strain
large in steel
small in rubber

Question 8

Hooke’s Law

what is it?

Answer 8

the linear proportionality of stress to strain

Question 9

When is something Hookeian?

Answer 9

when it’s Young’s modulus is constant

Question 10

Curvature

what is it?

Answer 10

the angular change of the tangent line per distance

Question 11

Radius of Curvature

what is it?

Answer 11

1/curvature

Question 12

Curvature

Scalar? Vector? or x order tensor?

Answer 12

2nd order tensor

Question 13

What is a 1st order tensor?

Answer 13

a vector

Question 14

What is a 0th order tensor?

Answer 14

a scalar

Question 15

Equation relating pressure, tension, and curvature

Answer 15

P = T * C

Question 16

Tension is the same thing as…?

Answer 16

tensile stress

Question 17

Electro-osmotic pressure

Scalar? Vector? or x order tensor?

Answer 17

scalar

Question 18

Auxin’s effect on plants (5)

Answer 18

• they bend towards light
• the have greater elongation in the dark
• they bend upwards relative to gravity
• branching is inhibited near growing tips
• roots sprout at the bottom of the plant

Question 19

Auxin does what to shoot sprouting?

Answer 19

inhibits it

Question 20

Auxin does what to root sprouting?

Answer 20

encourage it

Question 21

The better organic chemistry name for auxin:

Answer 21

indole acetic acid

Question 22

types of meristems:

Answer 22

• shoot meristem
• root meristem
• lateral meristem
• floral meristem

Question 23

Examples of apoptosis

Answer 23

• tail destruction in tadpoles
• destruction of cells between the lips and gums
• destruction of the cells between the fingers and toes
• destruction of cells of the neck to narrow it
• “necrotic zones” (should be apoptotic) in anterior and posterior limbs to narrow them
• 131 cells (mostly nerve) in C. elegans
• > 50% of motor and sensory nerves
• destruction of anti-self T-cells and B-cells
• destruction of virus-infected cells
• destruction of cells by chemotherapy