For an element to be considered a macronutrient _____.
it must be required in relatively large amounts
Why is nitrogen fixation an essential process?
Fixed nitrogen is often the limiting factor in plant growth.
A greenhouse experiment to test growth rates in tomato cultivars was conducted using sterile soil mix and watering with sterile solutions of water and fertilizer. Following germination, half of the plants in each group were transplanted into soil that was obtained from a nearby agricultural field (nonsterile), the other half into sterile soil. After several weeks the plants that were transplanted into nonsterile soil exhibited a much higher growth rate compared to the plants transplanted into sterile soil. The most likely explanation for this result is
the plants transplanted into the nonsterile soil were inoculated with mycorrhizae.
Mycorrhizae enhance plant nutrition mainly by
absorbing water and minerals through the fungal hyphae.
Other than the transport of materials, what is another function that vascular tissue performs in a leaf?
The tissue functions as a skeleton that reinforces the shape of the leaf.
How do cells in a meristem differ from cells in other types of plant tissue?
They continue to divide.
The driving force that pushes the root tip through the soil is primarily
elongation of cells behind the root apical meristem.
The following question is based on parts of a growing primary root.
I. root cap
II. zone of elongation
III. zone of cell division
IV. zone of cell differentiation
V. apical meristem
I, V, III, II, IV
Plants and animals respond differently to the environment. Which statement most accurately compares the responses of plants and animals to changes in their environment?
Animals tend to respond to changes in their environment by movement; plants tend to respond to changes in their environment by growth.
Select the best description of the significance of the meristems of plants.
Plant meristems are permanently embryonic regions within the plant body.
A vessel element would likely lose its protoplast in which section of a root?
zone of differentiation
Vascular cambium forms wood toward the stem's _____ and secondary phloem toward the stem's _____.
center ... surface
Cell division in the vascular cambium adds to the girth of a tree by adding new _____ to the layer's interior and _____ to the layer's exterior.
xylem ... phloem
As the epidermis is pushed outward and sloughed off, it is replaced by tissues produced by the _____.
Active transport involves all of the following except
diffusion of solute through the lipid bilayer of a membrane.
The value for Ψ in root tissue was found to be -0.15 MPa. If you take the root tissue and place it in a 0.1 M solution of sucrose (Ψ = -0.23 MPa), the net water flow would
be from the tissue into the sucrose solution.
Some botanists argue that the entire plant should be considered as a single unit rather than a composite of many individual cells. Which of the following cellular structures best supports this view?
In roots the _____ forces water and solutes to pass through the plasma membranes of _____ cells before entering the _____.
Casparian strip ... endodermis ... xylem
_____ provide(s) the major force for the movement of water and solutes from roots to leaves.
_____ cells are the cells that regulate the opening and closing of stomata, thus playing a role in regulating transpiration.
A student is performing a chemical analysis of xylem sap. This student should not expect to find much _____.
What is the main force by which most of the water within xylem vessels moves toward the top of a tree?
evaporation of water through stoma
In which plant cell or tissue would the pressure component of water potential most often be negative?
The opening of stomata is thought to involve
an increase in the solute concentration of the guard cells.
True or false? Root pressure can move water a long distance up the xylem because of the higher water potential of the xylem in comparison to the water potential in the surrounding cells.
Which of the following statements about the distribution of sap throughout a plant is true?
The mechanism that explains the movement of sugars throughout a plant is called the pressure-flow hypothesis.
Which of the following statements about xylem transport is true?
Water and minerals move through the root cortex into the xylem and upward through the stem and into leaves.
What characterizes the rates of photosynthesis and transport in a plant on a dry cloudy day?
Both the photosynthesis and transpiration rates are low.
True or false? The rate of sugar transport in a plant depends on the rate of photosynthesis, the rate of transpiration, and the difference in turgor pressure between the source and the sink.
Which structure formed by the male gametophyte allows sperm to reach the ovary of a flowering plant?
How is fertilization in flowering plants different from fertilization in other plant groups?
One sperm nucleus fuses with the egg to form a diploid zygote, whereas the other sperm nucleus fuses with two polar nuclei to form a cell that develops into endosperm.