BIO 152 Topics 23-24 Final Exam
UPDATED ACTUAL Exam Questions and
CORRECT Answers
Autotrophs - CORRECT ANSWER - self-feeding; they are organisms that use carbon
from simple substances to make organic compounds; they are usually photosynthetic, but they
don't have to be (chemotrophs); ex: algae, plants, some prokaryotes
Heterotrophs - CORRECT ANSWER - other-feeding; they are organisms that use carbon
from other organic sources to make organic compounds; they usually also get energy from
organic compounds; ex: animals, fungi, humans, some prokaryotes and protists
Photosynthesis occurs... - CORRECT ANSWER - in certain organelles in specialized cells
in the plant
Shoot system - CORRECT ANSWER - consists of reproductive organs, leaves and stem
Root system - CORRECT ANSWER - consists of roots
Cuticle - CORRECT ANSWER - non-cellular protective layer of the leaf that is
waterproof; prevents air from getting in or out
Epidermis - CORRECT ANSWER - cells that make the cuticle and protect the leaf
Mesophyll - CORRECT ANSWER - consist of the palisade mesophyll and the spongy
mesophyll; help with the photosynthesis process in the leaf
Stoma - CORRECT ANSWER - located at the bottom of the plant; have holes that allow
air in and out; contain guard cells
, Vascular tissue - CORRECT ANSWER - found in the leaf, stem and root; they are usually
non-photosynthetic and specialize in transport
Why is the arrangement of the mesophyll the way that it is? - CORRECT ANSWER - it
maximizes the amount of light and circulates CO2 in the leaf
CO2 and transpiration - CORRECT ANSWER - -mesophyll cells near the upper surface of
the leaf have columnar arrangement that maximizes light interception
-mesophyll cells close to the stomata have a honeycomb-like arrangement to allow CO2 to
spread easily throughout the leaf
-the concentration difference driving the diffusion of CO2 into the leaf is typically 100 times
smaller than the concentration difference driving the diffusion of water vapor out of the leaf
Plants lose several hundred H2O molecules for each CO2 that is fixed by photosynthesis
because: - CORRECT ANSWER - the concentration gradient is many times larger for
H2O than for CO2
Guard cell mechanism - CORRECT ANSWER - -uptake of solutes by guard cells causes
water to be drawn in by osmosis. As the guard cells swell, they bow apart, opening the stoma
-release of solutes causes water to flow out of the guard cells, closing the stoma
C3 plants - CORRECT ANSWER - most plants that open the stomata in day to allow CO2
in while the plant is doing photosynthesis; there is high water loss during the day
CAM plants - CORRECT ANSWER - some plants such as cacti that open the stomata at
night and close them in the day; they store CO2 as other organic compounds such as
crassulacean acid, and they require energy use and reduce water loss;
Where does the dry weight of the plant come from? - CORRECT ANSWER - air
Dry weight - CORRECT ANSWER - weight not including water
UPDATED ACTUAL Exam Questions and
CORRECT Answers
Autotrophs - CORRECT ANSWER - self-feeding; they are organisms that use carbon
from simple substances to make organic compounds; they are usually photosynthetic, but they
don't have to be (chemotrophs); ex: algae, plants, some prokaryotes
Heterotrophs - CORRECT ANSWER - other-feeding; they are organisms that use carbon
from other organic sources to make organic compounds; they usually also get energy from
organic compounds; ex: animals, fungi, humans, some prokaryotes and protists
Photosynthesis occurs... - CORRECT ANSWER - in certain organelles in specialized cells
in the plant
Shoot system - CORRECT ANSWER - consists of reproductive organs, leaves and stem
Root system - CORRECT ANSWER - consists of roots
Cuticle - CORRECT ANSWER - non-cellular protective layer of the leaf that is
waterproof; prevents air from getting in or out
Epidermis - CORRECT ANSWER - cells that make the cuticle and protect the leaf
Mesophyll - CORRECT ANSWER - consist of the palisade mesophyll and the spongy
mesophyll; help with the photosynthesis process in the leaf
Stoma - CORRECT ANSWER - located at the bottom of the plant; have holes that allow
air in and out; contain guard cells
, Vascular tissue - CORRECT ANSWER - found in the leaf, stem and root; they are usually
non-photosynthetic and specialize in transport
Why is the arrangement of the mesophyll the way that it is? - CORRECT ANSWER - it
maximizes the amount of light and circulates CO2 in the leaf
CO2 and transpiration - CORRECT ANSWER - -mesophyll cells near the upper surface of
the leaf have columnar arrangement that maximizes light interception
-mesophyll cells close to the stomata have a honeycomb-like arrangement to allow CO2 to
spread easily throughout the leaf
-the concentration difference driving the diffusion of CO2 into the leaf is typically 100 times
smaller than the concentration difference driving the diffusion of water vapor out of the leaf
Plants lose several hundred H2O molecules for each CO2 that is fixed by photosynthesis
because: - CORRECT ANSWER - the concentration gradient is many times larger for
H2O than for CO2
Guard cell mechanism - CORRECT ANSWER - -uptake of solutes by guard cells causes
water to be drawn in by osmosis. As the guard cells swell, they bow apart, opening the stoma
-release of solutes causes water to flow out of the guard cells, closing the stoma
C3 plants - CORRECT ANSWER - most plants that open the stomata in day to allow CO2
in while the plant is doing photosynthesis; there is high water loss during the day
CAM plants - CORRECT ANSWER - some plants such as cacti that open the stomata at
night and close them in the day; they store CO2 as other organic compounds such as
crassulacean acid, and they require energy use and reduce water loss;
Where does the dry weight of the plant come from? - CORRECT ANSWER - air
Dry weight - CORRECT ANSWER - weight not including water
