PNB 2250 Exam 1 Questions and
Answers 100% Pass
What traits to animals share? - ✔✔Eukaryotic, heterotrophic, able to move
Cell to cell connections in plants - ✔✔Plasmodesmo, flow of nutrients between cells
Cell to cell connections animals - ✔✔Tight junctions, strong connection
Some multicellularity advantages - ✔✔Cells have dedicated tasks (increase efficiency)
Not all genes expressed (saves energy)
Cells are further away from surface, ease on homeostasis
Disadvantage of multicellularity - ✔✔Need special cell/cell connections
Need for cell/cell communication
Need system for distribution of nutrients
Reason cells/tissues are different - ✔✔because the genes are expressed differently,
muscle tissues are different than skeletal tissues because of gene expression
Katelyn Whitman, All Rights Reserved © 2025 1
,Why is the fossil record incomplete? - ✔✔Needs to die near water, fossilization process
needs to be in a situation where there's no oxygen present, rapidly covered in soil so
overtime the soil compresses them and forms rock
Earth also continues to move, easier to find fossils closer to the earths crust, older fossils
are being pushed deep and deeper into the crust
Chanoflagelletes - ✔✔around 665 million years old, not an animal but is considered an
ancestor to animals. They have cell adhesion, cell signaling and animal specific genes
Anagenesis - ✔✔species formation without branching of the evolutionary line of
descent.
How do animals evolve? - ✔✔1. Heritable traits
2. Speciationm anagenesis, extinction
3. Adaptations to changing enivornments
- Different solutions to the same problems
- Change can be rapid
covergent evolution - ✔✔when structures look the same and share a common function
but are not derived from a common ancestor, think of falcon (bird) , bats (mammal,
pteridactyl (reptile)
Katelyn Whitman, All Rights Reserved © 2025 2
, PROOF THAT: limited possible solutions to problems faced by problems, evolution
drives these animals to the final solution
what animals must do? - ✔✔- Mechanism for excreting waste
- Mechanism for development and growth
- Energy input
why is immortality impossible? - ✔✔because the universe doesn't have infinite amount
of energy
Biochemistry is - ✔✔universal, ATP is used everywhere, DNA/RNA shared
George Wald - ✔✔Prevelance of CHNOPS, 96% of body mass
The chemistry is beneficial to life
Does the presence of an element in the body mean its essential to the body? - ✔✔No,
there has to be a biological property for it to be essential to the animal
Water stays liquid - ✔✔until 100 degrees Celsius,
Claude Bernard - ✔✔observed that the internal conditions of the body remain quite
constant even when external conditions vary greatly
Katelyn Whitman, All Rights Reserved © 2025 3
Answers 100% Pass
What traits to animals share? - ✔✔Eukaryotic, heterotrophic, able to move
Cell to cell connections in plants - ✔✔Plasmodesmo, flow of nutrients between cells
Cell to cell connections animals - ✔✔Tight junctions, strong connection
Some multicellularity advantages - ✔✔Cells have dedicated tasks (increase efficiency)
Not all genes expressed (saves energy)
Cells are further away from surface, ease on homeostasis
Disadvantage of multicellularity - ✔✔Need special cell/cell connections
Need for cell/cell communication
Need system for distribution of nutrients
Reason cells/tissues are different - ✔✔because the genes are expressed differently,
muscle tissues are different than skeletal tissues because of gene expression
Katelyn Whitman, All Rights Reserved © 2025 1
,Why is the fossil record incomplete? - ✔✔Needs to die near water, fossilization process
needs to be in a situation where there's no oxygen present, rapidly covered in soil so
overtime the soil compresses them and forms rock
Earth also continues to move, easier to find fossils closer to the earths crust, older fossils
are being pushed deep and deeper into the crust
Chanoflagelletes - ✔✔around 665 million years old, not an animal but is considered an
ancestor to animals. They have cell adhesion, cell signaling and animal specific genes
Anagenesis - ✔✔species formation without branching of the evolutionary line of
descent.
How do animals evolve? - ✔✔1. Heritable traits
2. Speciationm anagenesis, extinction
3. Adaptations to changing enivornments
- Different solutions to the same problems
- Change can be rapid
covergent evolution - ✔✔when structures look the same and share a common function
but are not derived from a common ancestor, think of falcon (bird) , bats (mammal,
pteridactyl (reptile)
Katelyn Whitman, All Rights Reserved © 2025 2
, PROOF THAT: limited possible solutions to problems faced by problems, evolution
drives these animals to the final solution
what animals must do? - ✔✔- Mechanism for excreting waste
- Mechanism for development and growth
- Energy input
why is immortality impossible? - ✔✔because the universe doesn't have infinite amount
of energy
Biochemistry is - ✔✔universal, ATP is used everywhere, DNA/RNA shared
George Wald - ✔✔Prevelance of CHNOPS, 96% of body mass
The chemistry is beneficial to life
Does the presence of an element in the body mean its essential to the body? - ✔✔No,
there has to be a biological property for it to be essential to the animal
Water stays liquid - ✔✔until 100 degrees Celsius,
Claude Bernard - ✔✔observed that the internal conditions of the body remain quite
constant even when external conditions vary greatly
Katelyn Whitman, All Rights Reserved © 2025 3
