BIO 150 Exam 3 Hyman Question and
answers verified to pass (44 pgs)
What is osmosis? - correct answer ✔Passive movement of water across a
cell membrane to balance the concentrations of solutions inside and outside
of a cell
Movement of water from a low concentration of solute to a high concentration
of solute
What is a hypertonic solution? - correct answer ✔A solution will a relatively
high concentration of solutes dissolved in it
Water rushes OUT of the cell from a low solute concentration to a high
concentration causing the cell to shrink (crenation)
- Ex. saltwater is typically hypertonic relative to the cell
What is a hypotonic solution? - correct answer ✔A solution will a relatively
low concentration of solutes dissolved in it
Water rushes INTO the cell from a low solute concentration to a high solute
concentration causing the cell to passively burst (lysis)
- Ex. freshwater is typically hypotonic relative to the cell
T or F: Red blood cells in humans will implode (shrink too much) if blood
becomes too dilute (aka loses too many salts). - correct answer ✔False
- will cause the cell to explode
,What is an isotonic solution? - correct answer ✔A solution with relatively
equal concentrations of solute in it
The amount of water transported in is equal to the amount of water
transported out
Ex. animal cells
Why is it ideal for animal cells to be in an isotonic environment? - correct
answer ✔animal cells do not have a cell wall nor contractile vacuoles
a cell wall prevents the plasma membrane from expanding and bursting easily
when placed in a hypotonic environment
contractile vacuoles pump excess water out of the cell
What is important about cell membranes in regards to diffusion? - correct
answer ✔Solute either can or can't cross the cell membrane, BUT water can
cross via osmosis
What is important about cell walls in regards to diffusion? - correct answer
✔Prokaryotes, unicellular algae (Eukarya), plants, and fungi have a cell wall
that keeps the plasma membrane from expanding and bursting
- acts like spandex for a cell
What is important about ION channels? - correct answer ✔WATER
FOLLOWS IONS
- They pump ions INTO the cell when in saltwater to prevent crenation
- They pump ions OUT of the cell in freshwater to prevent lysis
,T or F: In saltwater environments some unicellular organisms use ion
channels to pump ions OUT OF cells to make the environment
isotonic relative to the cellular fluid - correct answer ✔False
- this will not make the environment isotonic
What is a protist? - correct answer ✔a unicellular eukaryote that cannot be
classified as an animal, plant, fungi, or bacteria
What is a prokaryote? - correct answer ✔A unicellular organism that lacks a
nucleus and membrane bound organelles
What are contractile vacuoles? - correct answer ✔Compartments that take
up excess water inside the cell and contract to expel it outside the cell
- Ex. unicellular eukarya have contractile vacuoles
T or F: In freshwater environments, some unicellular organisms have
contractile vacuoles that pump water and ions INTO cells to maintain osmotic
balance. - correct answer ✔False
- contractile vacuoles pump water out
What is cell lysis? - correct answer ✔cell explodes
What is cell crenation? - correct answer ✔cell shrinks
What is turgor pressure? - correct answer ✔The pressure exerted by water
inside the cell against the cell wall
How do fungi actively osmoregulate to grow their hyphae? - correct answer
✔fungi push ions in to the cell to maintain turgor which creates a greater
, tonicity -> this causes increased osmotic pressure -> this causes increased
turgor pressure -> growth
T or F: Turgor pressure is the force of water pushing the plasma membrane
out against a rigid cell wall - correct answer ✔True
T or F: Fungal hyphae will use energy to actively pump ions OUT OF their
cells to generate the turgor pressure needed for growth - correct answer
✔False
- hyphae actively pump ions into their cells
T or F: Fungi do not have cell walls - correct answer ✔False
Fungi can produce above ground reproductive structures such as _______ -
correct answer ✔mushrooms
What are the mycelium and hyphae of a fungi? - correct answer ✔Mycelium
are the extended area below ground that consists of hyphae which moves
nutrients throughout the fungus.
- Mycelium need to grow to get nutrients
- Needs to actively osmoregulate to grow via turgor
The mycelium life stage functions as a ________ organism - correct answer
✔simple multicellular
The Kingdom Plantae has 5 characteristics: - correct answer ✔-
monophyletic group
- eukaryotes
- photosynthetic
answers verified to pass (44 pgs)
What is osmosis? - correct answer ✔Passive movement of water across a
cell membrane to balance the concentrations of solutions inside and outside
of a cell
Movement of water from a low concentration of solute to a high concentration
of solute
What is a hypertonic solution? - correct answer ✔A solution will a relatively
high concentration of solutes dissolved in it
Water rushes OUT of the cell from a low solute concentration to a high
concentration causing the cell to shrink (crenation)
- Ex. saltwater is typically hypertonic relative to the cell
What is a hypotonic solution? - correct answer ✔A solution will a relatively
low concentration of solutes dissolved in it
Water rushes INTO the cell from a low solute concentration to a high solute
concentration causing the cell to passively burst (lysis)
- Ex. freshwater is typically hypotonic relative to the cell
T or F: Red blood cells in humans will implode (shrink too much) if blood
becomes too dilute (aka loses too many salts). - correct answer ✔False
- will cause the cell to explode
,What is an isotonic solution? - correct answer ✔A solution with relatively
equal concentrations of solute in it
The amount of water transported in is equal to the amount of water
transported out
Ex. animal cells
Why is it ideal for animal cells to be in an isotonic environment? - correct
answer ✔animal cells do not have a cell wall nor contractile vacuoles
a cell wall prevents the plasma membrane from expanding and bursting easily
when placed in a hypotonic environment
contractile vacuoles pump excess water out of the cell
What is important about cell membranes in regards to diffusion? - correct
answer ✔Solute either can or can't cross the cell membrane, BUT water can
cross via osmosis
What is important about cell walls in regards to diffusion? - correct answer
✔Prokaryotes, unicellular algae (Eukarya), plants, and fungi have a cell wall
that keeps the plasma membrane from expanding and bursting
- acts like spandex for a cell
What is important about ION channels? - correct answer ✔WATER
FOLLOWS IONS
- They pump ions INTO the cell when in saltwater to prevent crenation
- They pump ions OUT of the cell in freshwater to prevent lysis
,T or F: In saltwater environments some unicellular organisms use ion
channels to pump ions OUT OF cells to make the environment
isotonic relative to the cellular fluid - correct answer ✔False
- this will not make the environment isotonic
What is a protist? - correct answer ✔a unicellular eukaryote that cannot be
classified as an animal, plant, fungi, or bacteria
What is a prokaryote? - correct answer ✔A unicellular organism that lacks a
nucleus and membrane bound organelles
What are contractile vacuoles? - correct answer ✔Compartments that take
up excess water inside the cell and contract to expel it outside the cell
- Ex. unicellular eukarya have contractile vacuoles
T or F: In freshwater environments, some unicellular organisms have
contractile vacuoles that pump water and ions INTO cells to maintain osmotic
balance. - correct answer ✔False
- contractile vacuoles pump water out
What is cell lysis? - correct answer ✔cell explodes
What is cell crenation? - correct answer ✔cell shrinks
What is turgor pressure? - correct answer ✔The pressure exerted by water
inside the cell against the cell wall
How do fungi actively osmoregulate to grow their hyphae? - correct answer
✔fungi push ions in to the cell to maintain turgor which creates a greater
, tonicity -> this causes increased osmotic pressure -> this causes increased
turgor pressure -> growth
T or F: Turgor pressure is the force of water pushing the plasma membrane
out against a rigid cell wall - correct answer ✔True
T or F: Fungal hyphae will use energy to actively pump ions OUT OF their
cells to generate the turgor pressure needed for growth - correct answer
✔False
- hyphae actively pump ions into their cells
T or F: Fungi do not have cell walls - correct answer ✔False
Fungi can produce above ground reproductive structures such as _______ -
correct answer ✔mushrooms
What are the mycelium and hyphae of a fungi? - correct answer ✔Mycelium
are the extended area below ground that consists of hyphae which moves
nutrients throughout the fungus.
- Mycelium need to grow to get nutrients
- Needs to actively osmoregulate to grow via turgor
The mycelium life stage functions as a ________ organism - correct answer
✔simple multicellular
The Kingdom Plantae has 5 characteristics: - correct answer ✔-
monophyletic group
- eukaryotes
- photosynthetic
