BIO 152 EXAM 3 WITH CORRECT
ANSWERS 2025
What are stomates for? correct answers >> Opens when
water moves into the guard cells.
Regulate the diffusion of gasses between the interior of the leaf
and the atmosphere.
let CO2 in
How do guard cells use solute concentration to open/close
stomates? correct answers >> manage the solute
concentration of the cytosol (and vacuole) with respect to the
areas outside of the cell.
What does the cell wall do? correct answers >> gives the
plant rigidity and strength
Challenges that a multicellular organism must overcome:
necessary adaptations correct answers >> Limits of
diffusion/distribution
Must stick together/support organism (in part)
Cell to cell communication
Regulate cell division and cell fate (development and
reproduction)
Defense
xylem correct answers >> transport water (and soil minerals)
dead cells
,phloem correct answers >> transports sugar and hormones
Phloem cells are a bit different as they are alive when they
function.
Have very few organelles.
Large connections between successive phloem cells
Which of the following would inhibit phloem function? correct
answers >> Inhibit ATP production in source cells.
Night time (so guard cells close stomates).
Phloem transport: correct answers >> Sugars transported
"actively" that is using ATP protein pumps
Water is pushed because of a pressure gradient
From high pressure to low.
Inhibition of ATP synthesis in leaf cells would correct answers
>> Inhibit xylem movement
Inhibit phloem movement
How does transport between xylem and phloem differ? correct
answers >> phloem transports hormones and sugar
xylem transports water
how does phloem work? correct answers >> use ATP protein
pumps
from high pressure to low
, how does xylem work? correct answers >> as h20 leaves the
stomates it pulls on the h2O collumn
What sort of pressure are xylem and phloem cells under
correct answers >> xylem is under negative pressure
phloem is under positive pressure
Which cells are alive at maturity and which dead? correct
answers >> xylem is dead
phloem cells are alive
Source to sink correct answers >> The "source" is the leaf
where sugar is made
The "sink" is where the sugar needs to go (e.g. fruits or the root in
fall).
Sugar is loaded by the leaf and taken out at the sink. When sugar
goes into the phloem, it draws more water into the phloem, which
has rigid walls.
Transpiration correct answers >> O2 water vapor released,
CO2 in
transpiration accounts for 80% of terrestrial water flux.
What does pollen do? correct answers >> double fertilization
Delivers two sperm cells to two different cells in the plant embryo
sac
ANSWERS 2025
What are stomates for? correct answers >> Opens when
water moves into the guard cells.
Regulate the diffusion of gasses between the interior of the leaf
and the atmosphere.
let CO2 in
How do guard cells use solute concentration to open/close
stomates? correct answers >> manage the solute
concentration of the cytosol (and vacuole) with respect to the
areas outside of the cell.
What does the cell wall do? correct answers >> gives the
plant rigidity and strength
Challenges that a multicellular organism must overcome:
necessary adaptations correct answers >> Limits of
diffusion/distribution
Must stick together/support organism (in part)
Cell to cell communication
Regulate cell division and cell fate (development and
reproduction)
Defense
xylem correct answers >> transport water (and soil minerals)
dead cells
,phloem correct answers >> transports sugar and hormones
Phloem cells are a bit different as they are alive when they
function.
Have very few organelles.
Large connections between successive phloem cells
Which of the following would inhibit phloem function? correct
answers >> Inhibit ATP production in source cells.
Night time (so guard cells close stomates).
Phloem transport: correct answers >> Sugars transported
"actively" that is using ATP protein pumps
Water is pushed because of a pressure gradient
From high pressure to low.
Inhibition of ATP synthesis in leaf cells would correct answers
>> Inhibit xylem movement
Inhibit phloem movement
How does transport between xylem and phloem differ? correct
answers >> phloem transports hormones and sugar
xylem transports water
how does phloem work? correct answers >> use ATP protein
pumps
from high pressure to low
, how does xylem work? correct answers >> as h20 leaves the
stomates it pulls on the h2O collumn
What sort of pressure are xylem and phloem cells under
correct answers >> xylem is under negative pressure
phloem is under positive pressure
Which cells are alive at maturity and which dead? correct
answers >> xylem is dead
phloem cells are alive
Source to sink correct answers >> The "source" is the leaf
where sugar is made
The "sink" is where the sugar needs to go (e.g. fruits or the root in
fall).
Sugar is loaded by the leaf and taken out at the sink. When sugar
goes into the phloem, it draws more water into the phloem, which
has rigid walls.
Transpiration correct answers >> O2 water vapor released,
CO2 in
transpiration accounts for 80% of terrestrial water flux.
What does pollen do? correct answers >> double fertilization
Delivers two sperm cells to two different cells in the plant embryo
sac
