Bio 109 Problem Set Questions and Answers
100% Solved
Under which of the following conditions will the stomata generally be "closed"?
-when guard cells are turgid (full of water)
when guard cells have low amounts of potassium ions (K+) inside them.
-at night, when guard cells have low amounts of potassium ions (K+) inside them.
-at night, when guard cells are turgid (full of water) and have low amounts of potassium ions
(K+) inside them. -at night, when guard cells have low amounts of potassium ions (K+)
inside them.
Which statement most accurately describes the Casparian strip?
-It is located in the walls between epidermal cells and cells of the cortex.
-It provides energy for the active transport of minerals into the stele from the cortex.
-It ensures that all water and dissolved substances must pass through a cell membrane before
entering the stele. -It ensures that all water and dissolved substances must pass through a
cell membrane before entering the stele.
,Which of the following is not part of the transpiration-cohesion-tension mechanism for the
ascent of xylem sap?
-Loss of water from the mesophyll cells, which initiates a pull of water molecules from
neighboring cells.
-Transfer of transpirational pull from one water molecule to the next, owing to cohesion by
hydrogen bonds.
-Hydrophilic walls of tracheids and vessels that help maintain the column of water against
gravity.
-Active pumping of water into the xylem roots.
-Lowing of ψ in the surface film of mesophyll cells due to transpiration. -Active pumping
of water into the xylem roots.
Based on the ABC model, what would be the structure of a flower (in a cross-section of the
flower, from the outside to the center) that had normal expression of genes A and C but lacked
expression of gene B?
-carpel-petal-petal-carpel
-carpel-stamen-stamen-carpel
, -sepal-petal-petal-sepal
-sepal-sepal-carpel-carpel
-Carpel-stamen-carpel-stamen -sepal-sepal-carpel-carpel
In a typical angiosperm, starting from the above-ground stem and moving to the tip of a
developing root, what is the correct order of structures?
-zone of maturation (differentiation), zone of elongation, zone of cell division, root cap.
-zone of maturation (differentiation), root cap, zone of cell division, zone of elongation.
-root cap, zone of cell division, zone of maturation (differentiation), zone of elongation.
-zone of cell division, root cap, zone of maturation (differentiation), zone of elongation.
-zone of cell division, zone of elongation, zone of maturation (differentiation), root cap. -
zone of maturation (differentiation), zone of elongation, zone of cell division, root cap.
Which of the following statements about xylem is incorrect?
-It conducts materials upward.
-It conducts materials within dead cells.
-It transports mainly sugars and amino acids.
100% Solved
Under which of the following conditions will the stomata generally be "closed"?
-when guard cells are turgid (full of water)
when guard cells have low amounts of potassium ions (K+) inside them.
-at night, when guard cells have low amounts of potassium ions (K+) inside them.
-at night, when guard cells are turgid (full of water) and have low amounts of potassium ions
(K+) inside them. -at night, when guard cells have low amounts of potassium ions (K+)
inside them.
Which statement most accurately describes the Casparian strip?
-It is located in the walls between epidermal cells and cells of the cortex.
-It provides energy for the active transport of minerals into the stele from the cortex.
-It ensures that all water and dissolved substances must pass through a cell membrane before
entering the stele. -It ensures that all water and dissolved substances must pass through a
cell membrane before entering the stele.
,Which of the following is not part of the transpiration-cohesion-tension mechanism for the
ascent of xylem sap?
-Loss of water from the mesophyll cells, which initiates a pull of water molecules from
neighboring cells.
-Transfer of transpirational pull from one water molecule to the next, owing to cohesion by
hydrogen bonds.
-Hydrophilic walls of tracheids and vessels that help maintain the column of water against
gravity.
-Active pumping of water into the xylem roots.
-Lowing of ψ in the surface film of mesophyll cells due to transpiration. -Active pumping
of water into the xylem roots.
Based on the ABC model, what would be the structure of a flower (in a cross-section of the
flower, from the outside to the center) that had normal expression of genes A and C but lacked
expression of gene B?
-carpel-petal-petal-carpel
-carpel-stamen-stamen-carpel
, -sepal-petal-petal-sepal
-sepal-sepal-carpel-carpel
-Carpel-stamen-carpel-stamen -sepal-sepal-carpel-carpel
In a typical angiosperm, starting from the above-ground stem and moving to the tip of a
developing root, what is the correct order of structures?
-zone of maturation (differentiation), zone of elongation, zone of cell division, root cap.
-zone of maturation (differentiation), root cap, zone of cell division, zone of elongation.
-root cap, zone of cell division, zone of maturation (differentiation), zone of elongation.
-zone of cell division, root cap, zone of maturation (differentiation), zone of elongation.
-zone of cell division, zone of elongation, zone of maturation (differentiation), root cap. -
zone of maturation (differentiation), zone of elongation, zone of cell division, root cap.
Which of the following statements about xylem is incorrect?
-It conducts materials upward.
-It conducts materials within dead cells.
-It transports mainly sugars and amino acids.
