What are the largest particles formed from the breakdown of rock?
answer
Gravel particles are the largest particles formed from the breakdown of rock.
question
True or false? Soil texture affects the amount of water available to plants; water is held best by clay and sand particles.
answer
False. Soil texture does indeed affect the amount of water available to plants, but water is held best by the smallest soil particles, clay and silt.
question
Which of the following steps occurs first during soil formation?
Mosses grow on the rock surface.
Lichens grow on the rock surface.
.
Organic material is added to the rock surface.
Weathering of solid rock occurs.
answer
Weathering is the process by which solid rock is broken down into smaller pieces and is the first step in soil formation.
question
Why is the decomposition of dead organisms important for soil formation?
answer
The process adds organic matter to the soil, which is necessary to support the growth of larger plants.
question
Which of the following statements about nutrient uptake by plants is true?
answer
Plants require other elements besides carbon, hydrogen, and oxygen to grow, and they can obtain these in soil. This statement is true; plants also require elements such as phosphorus, sulfur, and magnesium.
question
True or false? Plants use both active and passive transport processes to transport ions against their concentration gradients.
answer
False. Plants use passive transport, which requires no energy expenditure, to transport ions down their concentration gradients, but they can only use active transport, which requires energy in the form of ATP, to transport ions against their concentration gradients.
question
What defines a micronutrient?
answer
It is needed in very minute quantities.
question
What makes a nutrient an essential nutrient to plants?
answer
It is required for normal growth and reproduction.
question
The ability of plant roots to penetrate through soil is determined by which of the following?
answer
Soil texture
question
Moderate soil acidity means there are protons in the soil. Protons increase the availability of nutrients to plants by _____
answer
promoting cation exchange. Protons displace cations that are attached to clay particles.
question
Root hairs absorb nutrients from soil against the nutrient concentration gradient. To achieve this, root hairs use _____.
answer
proton pumps. Proton pumps create an electrical gradient, which plants then use to attract cations.
question
Anions are repelled, not attracted, by the electric gradient established by the proton pumps. How do plants absorb anions?
answer
By cotransport proteins
question
Legume plant roots are colonized by _____ to form root nodules.
answer
rhizobia. These bacteria live in the nodules and fix nitrogen from the soil.
question
What is biological nitrogen fixation
answer
The conversion of nitrogen gas into ammonia, nitrate, or nitrite by microbes
question
If a plant grows on another plant and depends on this plant for all its nutritional needs, including sugars, nutrients, and water, it can most specifically be called a(n) _____.
answer
parasitic plant
question
Carnivorous plants trap and digest insects to overcome _____.
answer
nitrogen deficiency in low-nitrogen soils. Due to low decomposition rates, nitrogen is in short supply in the wet environments where most carnivorous plants are found.
question
If you grew a plant with labeled atoms of carbon, nitrogen, hydrogen, and oxygen, which of these sources would dominate the mass of the plant?
answer
Labeled carbon and oxygen from carbon dioxide
question
Which of the following experiments is the best way to determine if an element is essential for plant growth?
answer
Grow plants using hydroponics with and without the element and measure plant growth and health.
question
Which of the following contributed to the dust bowl in the American southwest during the 1930s?
I. overgrazing by cattle
II. clear-cutting of forest trees
III. plowing of native grasses
IV. lack of soil moisture
answer
I, III, and IV
question
Which of the following are problems associated with intensive irrigation?
I. mineral runoff
II. overfertilization
III. aquifer depletion
IV. soil salinization
answer
only I, III, and IV
question
If you wanted to increase the cation exchange and water retention capacity of loamy soil, you should _____.
answer
add clay to the soil
question
What is the function of proton pumps localized in the plant plasma membrane?
answer
to create a membrane potential
question
What is the physical basis of the phototropic response?
answer
The phototropic response is based on cell elongation.
question
True or false? Auxin is asymmetrically distributed in shoots because the auxin on the side of the plant facing the source of light is destroyed.
answer
False. Auxin is asymmetrically distributed in shoots because the auxin on the side of the plant facing the source of light moves to the side of the plant away from the light.
question
Where does the majority of stem growth in a plant occur?
answer
The majority of stem growth in a plant occurs at the apical meristem.
question
Which of the following statements about hormones is true?
answer
Hormones can function at very low concentrations.
question
Which term describes the direction of auxin transport in a plant?
answer
Auxin transport is polar; it always travels downward.
question
How does auxin produce gravitropism in a plant that is placed on its side?
answer
Auxin accumulates on the lower surface of the root and inhibits elongation of cells in that region.
question
How does auxin produce phototropism?
answer
Auxin accumulates in cells on the side of the plant opposite the source of light and stimulates their elongation.
question
Why do only some of the plant cells exposed to a particular [hormone] respond?
answer
Only some cells have the receptors for the hormone.
question
Plant hormonal regulation differs from animal hormonal regulation in that _____.
answer
there are no dedicated hormone-producing organs in plants as there are in animals
question
When a signal arrives at the cell, it gets transduced. What is meant by the term signal transduction?
answer
Transduction means that the signal enters the cell in a different form than the form in which it reached the outside of the cell.
question
Using purified auxin, how would you manipulate a bed of roses to have stems that bend to the east?
answer
Place the auxin on the west side of their stems. The side of the stem that receives the auxin bends towards the other side. Placing it on the west side would result in bending toward the east.
question
What are phototropins?
answer
Phototropins detect blue light and initiate phototropic responses.
question
The Cholodny-Went hypothesis has been proposed to explain how plants bend toward a directional light source. What does this hypothesis suggest?
answer
Asymmetric auxin distribution causes differential cell elongation that causes bending.
question
Seed germination is induced by red light and inhibited by far-red light. What is responsible for this phenomenon?
answer
Phytochrome changing its shape when exposed to red versus far-red light
question
The percentage of germination of lettuce seeds exposed to far-red light, then blue light, and then red light compared to lettuce seeds that were exposed to far-red light only would be expected to be ____________________ .
answer
more because red light stimulates germination. It is the last light to which the seed is exposed that determines whether germination occurs at a high rate, and red light stimulates germination.
question
The mechanism by which root tips sense gravity so that they can grow downward is best explained by the _____.
answer
Statolith settling is thought to signal the direction of gravitational force.
question
According to the current evidence, what is the major function of cytokinins in plants?
answer
Cell division by activating cell-cycle-promoting genes. Cytokinins bind to receptors in the plasma membrane, which activate genes that regulate cell division.
question
Which of the following may happen if a plant has high ethylene levels inside plant tissues?
answer
Flower fading and leaf abscission
question
Which of the following signals indicates shade to a plant?
answer
far-red light
question
Why is it adaptive for lettuce seeds to be triggered to germinate by red light?
answer
Red light is present in bright sunlight that lettuce thrives in.
question
Thigmotropism is _____.
answer
plants responding to touch by changing the direction of growth
question
Why do plants have one hormone that promotes seed germination and another that suppresses seed germination? Why not just have one or the other?
answer
Antagonistic hormones allow finer control of germination. Different hormones trigger the production of different regulatory transcription factors.
question
The transduction pathway that activates systemic acquired resistance in plants is initially signaled by ________.
answer
methyl salicylate
Haven't found what you need?
Search for quizzes and test answers now
Quizzes.studymoose.com uses cookies. By continuing you agree to our cookie policy
