EXAM 1

Question 1

Characteristics of Life (7)

Answer 1

1. Metabolism
2. Reproduction
3. Response to stimuli
4. Growth
5. Movement
6. Genetic information
7. Cells/Cell membrane

Question 2

Oldest known evidence of fossilized cells

Answer 2

3.5 bya

Question 3

Atmospheric oxygen

Answer 3

2 bya

Question 4

Eukaryotes arrive.
Oxygen bonded with metals, creating oxides.
After saturation, appearance of atmospheric oxygen

Answer 4

1.5 bya

Question 5

First life: _________. After that, ________.

Answer 5

Heterotrophic, Autotrophic

Question 6

2 theories regarding membrane bound organelle origins?

Answer 6

1. AUTOGENOUS: Comes from within
2. EXOGENOUS: Comes from without.

Most are autogenous, via envagination

Question 7

ENDOSYMBIOTIC THEORY

Answer 7

Taking up and maintaining/utilizing free living organisms within oneself.

Question 8

Which came first, mitochondria or chloroplasts?

Answer 8

Mitochondria predate chloroplasts.

More variations of chloroplasts exist, few variations of mitochondria (BRANCHING OF LINEAGE).

Question 9

Cell size is limited by (4):

Answer 9

1. Gravity/weight
2. Transport of materials
3. Diffusion of materials through membranes.
4. Surface area to volume (SA^2, V^3). The cell would need more materials with less surface area to work with).

Question 10

RANDOM WALK EQUATION and the DIFFUSION COEFFICIENT for a cell:

Answer 10

Random walk equation:
t=d^2/2D, where t=time, d=distance, and D=diffusion coefficient.

Diffusion coefficient for a cell: 10^-8 m^2 s^-1

Question 11

3 ways cell can be large:

Answer 11

1. shape (long vs round, ie chara cells)
2. Inert materials (eggs)
3. Cell wall/extracellular matrix

Question 12

Find the volume of a cell (cube):

Answer 12

V = a^3, where a is the length of one edge.

Question 13

Find the weight (mass) of a cell:

Answer 13

M = V x D, Where M=mass, V=volume, D=density.

Question 14

Find the ‘Force’ of a cell pushing on another cell:

Answer 14

F = M x A, where F=force, M=mass, A=acceleration (in this case gravity, 9.8m^2 s^-1.
Remember that a Newton is kg m^2 s^-1

Question 15

Smallest known cells

Answer 15

Microplasma: 110 nm

Question 16

Average cell size (volume and weight):

Answer 16

Volume: 10^-15
Weight: 9.95 pN (10^-5 N)

Question 17

Where does ATP come from?

Answer 17

Proton gradient outside mitochondria (high outside, low inside).