UMKC BIOLOGY 109 EXAM 2 STUDY
COMPANION QUESTIONS WITH
COMPLETE ANSWERS
Explain how the orientation of cellulose microfibrils in a plant wall can control the
direction of cell expansion. - ANSWER-Expansion is always perpendicular to
cellulose mirofibrils.
In what significant way do plant developmental phases differ from those observed
with animals? - ANSWER-1. Plant cells do not migrate, as do bacteria or animal
cells. Plant shape forms based on the rate of cell division and the direction of
elongation. Although plants develop three basic tissue systems (dermal, ground, and
vascular), they don't rely on gastrulation to establish this layered system of tissues.
2. Plant development is continuous. New plant organs are formed throughout their
life by clusters of embryonic cells called meristem.
3. Plants have tremendous developmental plasticity. Lost plant parts can be
regenerated by meristems, and even entire plants can be regenerated from single
cells. In addition, environmental factors such as light and temperature can greatly
influence overall plant form.
What are organ identity genes? How does the ABC model of flower formation explain
the formation of the four types of floral organs? - ANSWER-1. Directly control organ
identity and also code for transcription factors that control the expression of other
genes // formation or function of the distinct organs of the flower.
2. There are four different parts of the flower: sepals, petals, stamens and carpels,
which are defined by A = Sepals // A+B = Petals // B+C = Stamen // C = Carple
Be able to account for the floral organ patterns that arise as a consequence of
mutations in the floral identity genes. - ANSWER-sepals (Se), petals (Pe), stamens
(St), and carpels (Ca).
A gene = Sepals
A+B = Petals
B+C = Stamens
C gene = Carpel
Cotransport - ANSWER-a process in which two substances are simultaneously
transported across a membrane by one protein, or protein complex which does not
have ATPase activity.
Osmosis - ANSWER-when a substance crosses a semipermeable membrane in
order to balance the concentrations of another substance. (move from high to low
concentration)
solute potential - ANSWER-is proportional to the number of dissolved solutes: more
solutes = more pressure = higher potential.
Solutes bind water molecules reducing the capacity of water to do work. (weird
symbol - s) of a solution is always negative
,pressure potential - ANSWER-the physical pressure on a solution. Can be positive or
negative relative to atmosphere. Plants usually under positive pressure - turgor
turgor - ANSWER-Pressure exerted by fluid in a cell that presses the cell membrane
against the cell wall. Turgor is what makes living plant tissue rigid. Loss of turgor,
resulting from the loss of water from plant cells, causes flowers and leaves to wilt.
aquaporin - ANSWER-membrane proteins that serve as channels in the transfer of
water, and in some cases, small solutes across the membrane.
What is the difference between a tap root and a fibrous root system - ANSWER-
Taproot: penetrates deep into the soil // primary root of the plant // dicots
Fibrous root: is shallow and does not penetrate as deeply // not the primary root of
the plant // monocots
What is the function of root hairs? - ANSWER-collect water and mineral nutrients
present in the soil and take this solution up through the roots to the rest of the plant.
What is an apical bud? Axillary bud? - ANSWER-Apical bud (terminal bud): allows
the plant to grow taller (towards top of plant)
Axillary buds (lateral bud): allows branching, giving a bushy growth. (on sides)
Both: found in dicot plants
What is meant by the term "apical dominance"? - ANSWER-The main, central stem
of the plant is dominant over (grows more strongly than) other side stems; on a
branch the main stem of the branch is further dominant over its own side branchlets
(Ex. Tree)
Distinguish among simple, compound, and doubly compound leaves? - ANSWER-
Simple Leaf: has a single undivided blade. (first image)
Compound Leaf: blade consists of multiple leaflets. (Leaflet has no axillary bud at its
base. // second image)
Doubly Compound Leaf: each leaflet is divided into smaller leaflets. (last image)
What are the three tissue types that comprise a plant? - ANSWER-Dermal Tissue
Vascular Tissue
Ground Tissue
What is the function of xylem? phloem? How are xylem and phloem similar and
different? - ANSWER-Xylem: conduct water and dissolved minerals from roots to
shoots // tracheids and vessel elements are tubular elongated cells that are dead at
functional maturity. (xylem moves through dead cells)
Phloem: transports sugars to roots and growth sites, such as developing leaves and
fruits // Sugar-conducting cells of the phloem are alive at functional maturity and
consist of sieve-tube elements.
What is meant by the term "indeterminate growth"? - ANSWER-A type of growth
characteristic of plants, in which the organism continues to grow as long as it lives.
, What are the three zones of cells in which root growth occurs? Which zone is
primarily responsible for pushing the root tip through the soil? - ANSWER-zone of
cell division: cells are actively dividing
zone of elongation: cells increase in length (PUSHES ROOT TIP THROUGH SOIL)
zone of maturation: cells differentiate to form different kinds of cells
What are the functions of the root cap? - ANSWER-Protects the apical meristem as
the root pushes through the soil. (apical meristem is the growth region in plants
found within the root tips and the tips of the new shoots and leaves.)
What is the function of the leaf stoma? - ANSWER-Allow exchange of CO2 and O2
with the surrounding air and the photosynthetic cells within the leaf.
What is secondary growth and what tissue(s) is (are) responsible for its production? -
ANSWER-Increases the diameter of stems and roots in woody plants. The
secondary plant body consists of tissues produced by the vascular cambium and
cork cambium.
Explain how cell division and enlargement contribute to plant formation. - ANSWER-
Cell division increases potential for growth by increasing cell numbers. Cell
expansion (particularly elongation) accounts for the increase in plant size
The plane in which a plant cell divides is determined during which stage of mitosis? -
ANSWER-Late Interphase
Symplast - ANSWER-the inner side of the plasma membrane in which water and
low-molecular-weight solutes can freely diffuse.
apoplast - ANSWER-the network of cell walls and intercellular spaces within a plant
body - the space outside the plasma membrane within which material can diffuse
freely.
bulk flow - ANSWER-movement of fluid in the xylem and phloem is driven by
pressure differences at opposite ends of the xylem vessels and sieve tubes.
transpiration - ANSWER-the loss of water vapor from leaves and other aerial parts of
the plant // produces negative pressure (tension) in the leaf, which exerts a pulling
force on water in the xylem, pulling water into the leaf.
guttation - ANSWER-the exudation of water droplets on tips of grass blades or the
leaf margins of some small, herbaceous eudicots. (DO NOT CONFUSE WITH DEW)
sugar sink - ANSWER-A plant organ that is a net consumer or storer of sugar.
Growing roots, shoot tips, stems, and fruits are sugar sinks supplied by phloem.
What are the three scales of transport in vascular plants? - ANSWER-1.Transport of
water and solutes by individual cells, such as root hairs.
2.Short-distance transport of substances from cell to cell at the levels of tissues and
organs.
3.Long-distance transport within xylem and phloem at the level of the whole plant.
COMPANION QUESTIONS WITH
COMPLETE ANSWERS
Explain how the orientation of cellulose microfibrils in a plant wall can control the
direction of cell expansion. - ANSWER-Expansion is always perpendicular to
cellulose mirofibrils.
In what significant way do plant developmental phases differ from those observed
with animals? - ANSWER-1. Plant cells do not migrate, as do bacteria or animal
cells. Plant shape forms based on the rate of cell division and the direction of
elongation. Although plants develop three basic tissue systems (dermal, ground, and
vascular), they don't rely on gastrulation to establish this layered system of tissues.
2. Plant development is continuous. New plant organs are formed throughout their
life by clusters of embryonic cells called meristem.
3. Plants have tremendous developmental plasticity. Lost plant parts can be
regenerated by meristems, and even entire plants can be regenerated from single
cells. In addition, environmental factors such as light and temperature can greatly
influence overall plant form.
What are organ identity genes? How does the ABC model of flower formation explain
the formation of the four types of floral organs? - ANSWER-1. Directly control organ
identity and also code for transcription factors that control the expression of other
genes // formation or function of the distinct organs of the flower.
2. There are four different parts of the flower: sepals, petals, stamens and carpels,
which are defined by A = Sepals // A+B = Petals // B+C = Stamen // C = Carple
Be able to account for the floral organ patterns that arise as a consequence of
mutations in the floral identity genes. - ANSWER-sepals (Se), petals (Pe), stamens
(St), and carpels (Ca).
A gene = Sepals
A+B = Petals
B+C = Stamens
C gene = Carpel
Cotransport - ANSWER-a process in which two substances are simultaneously
transported across a membrane by one protein, or protein complex which does not
have ATPase activity.
Osmosis - ANSWER-when a substance crosses a semipermeable membrane in
order to balance the concentrations of another substance. (move from high to low
concentration)
solute potential - ANSWER-is proportional to the number of dissolved solutes: more
solutes = more pressure = higher potential.
Solutes bind water molecules reducing the capacity of water to do work. (weird
symbol - s) of a solution is always negative
,pressure potential - ANSWER-the physical pressure on a solution. Can be positive or
negative relative to atmosphere. Plants usually under positive pressure - turgor
turgor - ANSWER-Pressure exerted by fluid in a cell that presses the cell membrane
against the cell wall. Turgor is what makes living plant tissue rigid. Loss of turgor,
resulting from the loss of water from plant cells, causes flowers and leaves to wilt.
aquaporin - ANSWER-membrane proteins that serve as channels in the transfer of
water, and in some cases, small solutes across the membrane.
What is the difference between a tap root and a fibrous root system - ANSWER-
Taproot: penetrates deep into the soil // primary root of the plant // dicots
Fibrous root: is shallow and does not penetrate as deeply // not the primary root of
the plant // monocots
What is the function of root hairs? - ANSWER-collect water and mineral nutrients
present in the soil and take this solution up through the roots to the rest of the plant.
What is an apical bud? Axillary bud? - ANSWER-Apical bud (terminal bud): allows
the plant to grow taller (towards top of plant)
Axillary buds (lateral bud): allows branching, giving a bushy growth. (on sides)
Both: found in dicot plants
What is meant by the term "apical dominance"? - ANSWER-The main, central stem
of the plant is dominant over (grows more strongly than) other side stems; on a
branch the main stem of the branch is further dominant over its own side branchlets
(Ex. Tree)
Distinguish among simple, compound, and doubly compound leaves? - ANSWER-
Simple Leaf: has a single undivided blade. (first image)
Compound Leaf: blade consists of multiple leaflets. (Leaflet has no axillary bud at its
base. // second image)
Doubly Compound Leaf: each leaflet is divided into smaller leaflets. (last image)
What are the three tissue types that comprise a plant? - ANSWER-Dermal Tissue
Vascular Tissue
Ground Tissue
What is the function of xylem? phloem? How are xylem and phloem similar and
different? - ANSWER-Xylem: conduct water and dissolved minerals from roots to
shoots // tracheids and vessel elements are tubular elongated cells that are dead at
functional maturity. (xylem moves through dead cells)
Phloem: transports sugars to roots and growth sites, such as developing leaves and
fruits // Sugar-conducting cells of the phloem are alive at functional maturity and
consist of sieve-tube elements.
What is meant by the term "indeterminate growth"? - ANSWER-A type of growth
characteristic of plants, in which the organism continues to grow as long as it lives.
, What are the three zones of cells in which root growth occurs? Which zone is
primarily responsible for pushing the root tip through the soil? - ANSWER-zone of
cell division: cells are actively dividing
zone of elongation: cells increase in length (PUSHES ROOT TIP THROUGH SOIL)
zone of maturation: cells differentiate to form different kinds of cells
What are the functions of the root cap? - ANSWER-Protects the apical meristem as
the root pushes through the soil. (apical meristem is the growth region in plants
found within the root tips and the tips of the new shoots and leaves.)
What is the function of the leaf stoma? - ANSWER-Allow exchange of CO2 and O2
with the surrounding air and the photosynthetic cells within the leaf.
What is secondary growth and what tissue(s) is (are) responsible for its production? -
ANSWER-Increases the diameter of stems and roots in woody plants. The
secondary plant body consists of tissues produced by the vascular cambium and
cork cambium.
Explain how cell division and enlargement contribute to plant formation. - ANSWER-
Cell division increases potential for growth by increasing cell numbers. Cell
expansion (particularly elongation) accounts for the increase in plant size
The plane in which a plant cell divides is determined during which stage of mitosis? -
ANSWER-Late Interphase
Symplast - ANSWER-the inner side of the plasma membrane in which water and
low-molecular-weight solutes can freely diffuse.
apoplast - ANSWER-the network of cell walls and intercellular spaces within a plant
body - the space outside the plasma membrane within which material can diffuse
freely.
bulk flow - ANSWER-movement of fluid in the xylem and phloem is driven by
pressure differences at opposite ends of the xylem vessels and sieve tubes.
transpiration - ANSWER-the loss of water vapor from leaves and other aerial parts of
the plant // produces negative pressure (tension) in the leaf, which exerts a pulling
force on water in the xylem, pulling water into the leaf.
guttation - ANSWER-the exudation of water droplets on tips of grass blades or the
leaf margins of some small, herbaceous eudicots. (DO NOT CONFUSE WITH DEW)
sugar sink - ANSWER-A plant organ that is a net consumer or storer of sugar.
Growing roots, shoot tips, stems, and fruits are sugar sinks supplied by phloem.
What are the three scales of transport in vascular plants? - ANSWER-1.Transport of
water and solutes by individual cells, such as root hairs.
2.Short-distance transport of substances from cell to cell at the levels of tissues and
organs.
3.Long-distance transport within xylem and phloem at the level of the whole plant.
