PNB 2250 – EXAM 123 AND 4
How are plant cells held together?
Plasmodesma
Plasmodesma
Flow of nutrients between cells
How are animal cells held together?
Tight junctions
Tight junctions
Unique connections for animal cells
2 absolute requirements of animals:
1. Control Systems
2. Distribution Systems
True/False: gene number is proportional to physical structure or
complexity
FALSE - it is NOT proportional
,Which fossils do we find the most of?
Newer, marine animals
Extant ancestor of animals
Chaonoflagellates
Examples of convergent evolution
- Flight in insects, bats, birds
- Opposable thumbs in opossums
- Echolocation in whales, bats, shrews
Why is immortality impossible?
The universe does not have an infinite amount of energy
George Wald
Discovered the prevalence of CHONPS - 96% of body mass
,4 characteristics of CHONPS
- 2 or fewer electron shells
- strong intramolecular bonds
- double and triple bonds
- maintenance of structure
Animals strive to maintain their internal environment suitable for life,
or _____
Homeostasis
Claude Bernard
discovered homeostasis
Homeostasis
A constant internal environment in the face of a changing external
environment
, 3 examples of components of homeostasis
Body temp.
Blood pH
Blood glucose
Components of a feedback loop
- Sensor
- Variable
- Output
Feedback Loop: sensor
A protein based biochemical amplifier
Feedback Loop: Output
Change in physiological variable
Most common type of feedback
Negative
How are plant cells held together?
Plasmodesma
Plasmodesma
Flow of nutrients between cells
How are animal cells held together?
Tight junctions
Tight junctions
Unique connections for animal cells
2 absolute requirements of animals:
1. Control Systems
2. Distribution Systems
True/False: gene number is proportional to physical structure or
complexity
FALSE - it is NOT proportional
,Which fossils do we find the most of?
Newer, marine animals
Extant ancestor of animals
Chaonoflagellates
Examples of convergent evolution
- Flight in insects, bats, birds
- Opposable thumbs in opossums
- Echolocation in whales, bats, shrews
Why is immortality impossible?
The universe does not have an infinite amount of energy
George Wald
Discovered the prevalence of CHONPS - 96% of body mass
,4 characteristics of CHONPS
- 2 or fewer electron shells
- strong intramolecular bonds
- double and triple bonds
- maintenance of structure
Animals strive to maintain their internal environment suitable for life,
or _____
Homeostasis
Claude Bernard
discovered homeostasis
Homeostasis
A constant internal environment in the face of a changing external
environment
, 3 examples of components of homeostasis
Body temp.
Blood pH
Blood glucose
Components of a feedback loop
- Sensor
- Variable
- Output
Feedback Loop: sensor
A protein based biochemical amplifier
Feedback Loop: Output
Change in physiological variable
Most common type of feedback
Negative
