Students are sketching diagrams of the shoot system of angiosperms for a plant anatomy class. These lists describe diagrams made by four students. Which diagram represents the shoot system incorrectly?
- leaves, stem, fruit, flowers
- stem, fruit, leaves, branches
- flowers, leaves, branches, stem
- stem, hair roots, leaves, flowers, branches
An herbicide causes roots to shrivel and die. What is the most direct consequence for a plant treated with the herbicide?
- The plant will grow normally but will not bloom.
- The plant will dry out because water is not reaching all its organs.
- New leaves will form to compensate for the dying of roots
- The plant will grow normally but will not produce fruit
Scientists label cells in the lateral meristem of a sapling with a dye to follow the developmental fate of the cells. After several weeks, sections are prepared from the sapling and observed under the microscope. Which tissues are most likely to be stained by the dye that was injected into the lateral meristem?
- Vascular tissue to transport nutrients and water
- The tip of plant to promote growth of plant
- Secondary xylem to increase girth of stem
- Epidermis to cover the plant
A lab technician is looking for a slide that shows an example of permanent tissue. Which slide is the best choice?
- a slide of the apical bud of a stem
- a slide obtained from the intercalary meristems
- lateral meristem in the vascular cambium
- secondary xylem
Which region of a plant is most likely to contribute to an increase in its length?
- tip of leaves
- dermal layer
- vascular bundles
- tip of the root
You are measuring the effect of a new fertilizer on the growth of lawns. Which of the following tissues should be the target of the fertilizer?
- apical meristem
- lateral meristem
- intercalary meristem
- vascular bundle
The dermal tissue of a plant provides __ for the plant.
- transport of water
- transport of minerals
A branch of celery is soaked in a glass of water containing food dye. Soon, the tough fibers in celery branch are colored. What tissue do the tough fibers contain?
- dermal tissue
- ground tissue
A plant biologist is examining sections of plant tissue under the microscope. The slides are not labeled and the biologist is interested in simple tissues. Which of the following slides is a sample of a simple tissue?
- cells dividing rapidly in a stem
- root cambium showing different types of cells
- parenchyma showing only one type of cell
- leaf displaying the vascular bundle where diverse types of cells are involved in transport
Students are asked to sort tissue slides into simple and complex tissues. How should they recognize a complex tissue through the microscope?
- Complex tissue has a variety of cell types that fulfill different functions.
- Only complex tissue is observed in adult plants.
- Complex tissue appears only in lateral roots and branches.
- Complex tissues contain cells that are strikingly different in appearance but perform the same function.
Students are sketching diagrams of the reproductive system of angiosperms for a plant anatomy class. These lists describe diagrams made by four students. Which diagram represents the reproductive system correctly?
- hair roots, lateral roots, and taproot
- stem, branches, and leaves
- flowers and fruit
- leaves, petioles, and branches
Plant scientists are interested in isolating meristematic tissue for an experiment. They sample several regions of a plant. Which sample is most likely to contain meristematic tissue?
- the thin epidermis that covers an onion bulb
- a sample of fruit tissue
- a sample of actively dividing cells located at the tip of an onion root
- a region of the mesenchyme
This sketch of a stem shows the region to which leaves are attached. Which version of the sketch is correctly labeled?
- version A
- version B
- version C
- version D
A student examines a plant part and concludes that it is part of a stem. The presence of _____fully justifies the student’s conclusion.
- vascular tissue
- nodes and internodes
- epidermal layer
- stored carbohydrates
A student reported vascular tissue while inspecting a cross-section of a plant stem under the microscope. Which cells would allow the student to identify vascular tissue?
- tracheids, vessel elements, sieve-tube cells, and companion cells
- cells actively dividing at the apex of the stem
- parenchyma cells at the center of the section
- cells covered by a cuticle at the outside edge of the section
While using a microscope to observe a stem section stained with a dye that binds lignin, a student notices that some cells with thick cell walls and large hollow centers are preferentially stained. He concludes that those cells belong to the ____.
- meristematic tissue
- vascular tissue
- ground tissue
- dermal tissue
Scientists are cataloguing slides of plant cross-sections. They are interested in finding examples of secondary growth. Which example contributes to secondary growth?
- apical meristem, which contributes to increase in length
- vascular cambium, which contributes to increase in thickness or girth
- root region, which shows an increase in root hairs
- stems, which show an increase in number of leaves
Where is the vascular cambium located in an established woody plant?
- between the primary xylem and the primary phloem
- between the secondary xylem and the primary phloem
- between the secondary xylem and the secondary phloem
- between the primary xylem and the secondary phloem
Dendrochronology is the science of dating the age of a tree by counting the annual rings in a tree trunk. If scientists are determining the age of a tree by dendrochronology, what tissue are they looking at?
- primary xylem
- secondary xylem
- primary phloem
- vascular cambium
While examining the stump of a recently cut tree, you count four thick rings alternating with four rings that are much narrower and appear denser. From this observation, you should conclude that the tree is __.
- two years old, because each ring corresponds to a season
- three years old, because the first ring you observe is the primary xylem
- four years old, because secondary xylem grows only in the spring and fall of each year
- eight years old, because there are eight rings in all
Many forms of modified organs exist in plants. What is a rhizome?
- an underground stem with fleshy leaves modified for food storage as in onions
- a solid, underground stem covered with scales formed by some plants such as crocuses
- an aboveground stem with buds as seen in strawberry plants
- a modified horizontal stem that grows underground as seen in irises
Modified organs are part of survival strategies of plants. Which of these plants has a flattened, photosynthetic stem that could be mistaken for a leaf?
Analyzing cross-sections of different parts of a plant in a plant anatomy class, students categorized the most frequently encountered types of cells in plant tissues. Which student gave the most accurate report?
- Student A reported that meristematic cells were the most abundant.
- Student B tallied mostly collenchyma cells.
- Student C noticed mostly sclerenchyma cells.
- Student D observed that parenchyma cells were the most abundant.
A carrot is an example of a tap root. Which of these can also be classified as a tap root?
- the large network of superficial roots of a cactus
- a dandelion anchored by a long main root that penetrates deep into the soil
- a banyan tree’s system of roots that dangle from the branches
- a round organ that stores carbohydrates
Some weeds are anchored by taproots. They cause problems to gardeners because they are ___.
- easy to pull up because the root system is shallow
- difficult to pull up because their taproots penetrate deep into the soil
- difficult to pull up because they are anchored by an extensive network of roots
- easy to pull up because there is not a large network to anchor the plant
One of the major concepts of biology is that form follows function. If that is so, what can be deduced from the shape and location of the root cap?
- It provides protection to the root tip.
- It absorbs water and minerals.
- It acts as a storage tissue.
- It replicates actively to elongate the root.
A technician is preparing microscope slides that will display the different stages of mitosis from root samples. He compares sections from several areas of the root. Which is the best prediction of his observation?
- The technician will see mostly mitotic cells in the root cap.
- The technician will observe mitotic figures in the meristematic tissue below the cap.
- The technician will observe cell division in the elongation zone.
- The technician will see that most mitotic cells are in the maturation zone.
Selective uptake of minerals in the root is measured and the results are analyzed. If you analyze the data, what should you see?
- Pericycle is the tissue where selectivity takes place.
- The endodermis acts as a selective barrier for minerals taken up by the root.
- The epidermis acts as a selective barrier for minerals.
- The root cap functions as a selective barrier for minerals taken up by the root.
Sudan Red dye stains primarily waxy, hydrophobic material. A root is soaked in Sudan Red and analyzed for stain retention. What is a scientist observing sections of the root under a microscope likely to see?
- The cells in the cortex show the deepest stain.
- The tracheids in the xylem contain mostly lipid droplets stained with Sudan Red.
- The Casparian strip will show the deepest coloring.
- The sieve elements in the phloem show staining with Sudan Red because of transported oil droplets.
In environments where light is scarce, some plants grow on other plants to reach light. Which root system would best support this mode of life?
- Epiphytic root system in the air
- Prop roots that support the trees to stand in muddy soil
- Adventitious roots that grow above ground
- Taproots that penetrate the soil
A section of buttercup root is stained with iodine, which stains starch blue. Where would you expect to find the blue granules indicative of starch?
- parenchymal cells of the cortex
- cells of phloem
- cells of the epidermis
- cells of the endodermis and pericycle
Which of the following best describes a fibrous root system?
- covers a limited surface and contains few roots
- consists of a single main root with adjacent smaller roots
- covers a large area and contains an extensive network of roots
- contains several major, interconnected roots
Ethylene promotes the fall of leaves by triggering the death of cells and abscission. What region of the leaf responds to ethylene?
- the lamina, where photosynthesis takes place
- the vein, which carries nutrients and water in and out of the leaf
- the petiole, which attaches the leaf to the stem
- the margin, which is serrated and may be sharp
A horticulture student is classifying plants as dicots or monocots according to their leaf structure. How is a dicot leaf recognizable?
- It does not have stipules
- The veins form a network pattern.
- The veins are parallel.
- The veins form forks and fan out.
Multiple leaves attached to the same node are fairly unusual. One example is found on the macadamia nut tree. The leaf arrangement in the macadamia tree is best characterized as ___.
You picked leaves while on a hike. One specimen appears to show an opposite arrangement. On closer inspection, you notice that those are not leaves, but leaflets attached to a midrib vein. What type of leaf arrangement are you observing?
- palmately compound
- pinnately compound
- simple whorled
- simple spiral
Chlorophyll, the primary photosynthetic pigment, emits light in the red region of the visible spectrum. The presence of chlorophyll correlates with photosynthetic capacity. Under a fluorescent microscope, what part of a leaf would fluoresce in the red region of the spectrum?
- vascular bundle
A pulse of radioactive carbon dioxide (CO2) is provided to isolated leaves. In which tissue would you expect to see radioactive glucose appear first?
- in the cells of the mesophyll
- in the sieve elements of the phloem
- vessels of the xylem
Which adaptation is most likely to be found in a desert environment?
- broad leaves to capture sunlight
- spines instead of leaves
- needle-like leaves
- wide, flat leaves that can float
In the collection of a botanical garden, plants are classified according to the environments in which they thrive. What plant would have large leaves covered with a thick upper cuticle and wide flat blades and possess large air spaces (chambers) within its mesophyll tissue?
- a water lily floating on water
- a pine tree growing in the cold and dry taiga
- a cactus growing in a hot, sunny, and dry environment
- an orchid hanging from a tree in a tropical forest
If a gardener trims leaves off of the stem of a rose, which part of the leaf is cut?
On a field trip, students collect a few samples to analyze back in their classroom. One student picks a blade of grass in the field and identifies it as a dicot leaf, but his partner thinks it is a monocot. Which explanation supports his partner’s opinion?
- The leaf displays a thin lamina.
- There is no petiole.
- The margins are serrated.
- The venation is parallel.
Which of the following physical components of the total water potential cannot be manipulated by the plant because it represents the interaction between water and hydrophilic molecules lining the vessels and tracheids?
- solute concentration
- matric potential
If the concentration of solute increases in a cell, the water potential will ________ inside the cell and water will move ________ the cell.
- increase; out of
- increase; into
- decrease; into
- decrease; out of
Plants can modify their water potential by opening and closing their stomata to modulate the rate of respiration according to environmental conditions. Which of the following environmental conditions would cause the stomata to close?
- increased temperature
- high oxygen concentration
- high relative humidity
- high light levels
Plants regulate their internal water potential by opening and closing stomata. Which events take place when stomata open?
- Water vapor is lost to the external environment, increasing the rate of transpiration.
- Water vapor is lost to the external environment, decreasing the rate of transpiration.
- Water vapor enters the spaces in the mesophyll, increasing the rate of transpiration.
- The rate of photosynthesis drops when stomata open.
A pulse of sugars labelled with a fluorescent dye is supplied to leaves of young plants. After a brief interval, tissue sections are obtained from the plant and examined under the fluorescence microscope. Tissues are scored for the presence of fluorescence and ranked from very high to low fluorescence. Which cells would contain the most fluorescence?
- companion cells
- sieve elements
Sugars produced in the leaf are distributed throughout the plant body. An experimenter supplies plants with a pulse of radiolabeled CO2 in a control chamber. The movement of radioactively labeled sugar is monitored in the plant by analyzing different cells content over time. Where will the radiolabeled sugar appear immediately after detection in the leaf cells?
- tracheids and vessel elements
- tracheids and companion cells
- vessel elements and companion cells
- sieve-tube elements and companion cells
Solute potential decreases when solutes are added to a cell. The consequence is to draw water into the cell. Which of these terms corresponds to solute potential?
- water potential
- pressure potential
- osmotic potential
- negative potential
Plants have many light responses, including photosynthesis, photoperiodism, and phototropism (growing toward a light source). Specific wavelengths of light absorbed by different photoreceptors trigger responses. This table shows some of the most common photoreceptors and pigments and the major regions of the spectrum in which they are active. Research shows that plants bend toward blue light. Even mutant plants that lack carotenoids will bend toward blue light. The photoreceptor is likely _____.
Plant flowering is an example of photoperiodism, the response to the length of nights or periods of darkness. A plant that responds to short nights followed by increasingly longer nights will most likely flower in _____.
Gravitropism is plant growth in response to gravity. A dahlia stem was toppled by the wind and is lying lies on the ground. After a few days, you would likely notice that ________ .
- the stem is growing by curving toward the roots
- the stem is growing by trailing on the ground
- the stem is growing by curving upward
- the plant is wilting
Plants most likely detect gravity by sensing the direction in which some components respond to gravity. A mutant plant has roots that grow in all directions. Which organelle would you expect to be missing in the cell?
In an experiment to release seeds from dormancy, several hormones were applied to seeds and germination rates were computed. Which plate likely showed the highest rate of germination?
- abscisic acid
- gibberellic acid
Green bananas or unripe avocadoes can be kept in a brown bag to ripen faster. What hormone is involved?
- abscisic acid
- gibberellic acid
A lab teacher wants to demonstrate thigmonastic behavior of a plant. Which of these experiments is the best choice?
- Observe flowering of a plant after a brief red light irradiation in the middle of a dark period.
- Observe whether seedlings bend towards blue light.
- Observe whether a tree grows bent in the direction of the prevailing wind.
- Touch the plant Mimosa pudicaand observe the closing of the leaflets.
A lab teacher wants to demonstrate thigmotropic behavior of a plant. Which of these experiments is the best choice?
- roots growing downwards
- venus fly trap snapping on an insect
- seedling germinating under a stone and growing upward and away from the stone
- plant growing towards a shaded area
Which is a protection against microbial pathogens?
- thorns and spines
- cutin and suberin
- neurotoxic compounds
- bitter-tasting alkaloids
Many secondary alkaloids are poisonous to the nervous system. What organisms are targeted by the alkaloids?
Red light converts phytochrome red (Pr) to __.
- an inactive form of Pr
- a breakdown product
- the far red light absorbing form called Pfr
Circadian rhythm refers to a pattern of behavior that recurs on a daily schedule in the absence of an external stimulus. Flowers open and close according to a circadian rhythm. If a plant is transferred to a dark environment, what will happen?
- Flowers will stay closed.
- Flowers will stay open.
- Flowers will open and close every day at the same time.
- Flowers will open and close at random times.