1: What is drought tolerance in plants?
A: The ability of plants to grow in shaded conditions
B: The ability of plants to maintain biomass during drought
C: Plants’ immunity to pests
D: Plants’ ability to produce more flowers
Correct Answer: B
Explanation: Drought tolerance is the ability by which a plant maintains its biomass production during arid or drought conditions.
2: Which plant mechanism involves surviving dry conditions with desiccation tolerance?
A: Photosynthesis
B: Flowering
C: Detoxification
D: Desiccation tolerance
Correct Answer: D
Explanation: Desiccation tolerance is a natural adaptation for surviving dry conditions.
3: What role does genetic engineering play in drought tolerance of crops like corn, wheat, and rice?
A: Reduces their growth rate
B: Makes them more flavorful
C: Increases tolerance to drought
D: Makes them immune to insects
Correct Answer: C
Explanation: New crop varieties are created via genetic engineering to become increasingly tolerant to drought.
4: How do mycorrhizal associations in roots help plants adapt to drought?
A: By slowing plant growth
B: By blocking sunlight
C: By accelerating plant adaptation to drought
D: By reducing plant size
Correct Answer: C
Explanation: The type of mycorrhizal associations formed in roots can determine how fast plants can adapt to drought.
5: What are stomata?
A: Cell walls
B: Water storage units
C: Pores on leaves for gas exchange
D: Flower petals
Correct Answer: C
Explanation: Stomata are pores on the leaves that regulate gas exchange and water loss.
6: During drought, what happens to carotenoids in plants?
A: They remain unchanged
B: They increase in number
C: They degrade
D: They turn into anthocyanins
Correct Answer: C
Explanation: Carotenoid degradation is part of the plant’s response to drought conditions.
7: What is the role of abscisic acid (ABA) in drought tolerance?
A: It facilitates photosynthesis
B: It regulates water uptake
C: It acts as a transcriptional factor
D: It provides structural support
Correct Answer: C
Explanation: ABA-responsive element-binding factors (AREB) are part of the molecular control of drought tolerance.
8: How do plants typically respond to short-term water shortages?
A: By increasing growth rate
B: By decreasing water uptake
C: By closing stomata and limiting growth
D: By producing more flowers
Correct Answer: C
Explanation: In short-term water shortages, plants minimize water loss by closing stomata and slowing down growth.
9: What is a key short-term response of roots to drought stress?
A: Rapid leaf production
B: Cell-drought signaling
C: Increased chlorophyll production
D: High transpiration rates
Correct Answer: B
Explanation: Cell-drought signaling is a key short-term response in roots during drought stress.
10: In drought conditions, what is a long-term response seen in the above-ground part of the plant?
A: Increased transpiration area
B: Enhanced root growth
C: Increased sugar production
D: Reduced transpiration area
Correct Answer: D
Explanation: Reducing the transpiration area helps the plant conserve water during long-term drought conditions.
11: What type of protein family does DREB belong to?
A: Photosynthetic proteins
B: Root growth proteins
C: Transcription factors
D: Structural proteins
Correct Answer: C
Explanation: DREB proteins are transcription factors that play roles in drought tolerance.
12: What is the function of the DREB1A gene in Arabidopsis?
A: Enhances flower color
B: Enhances drought and cold tolerance
C: Increases stem length
D: Decreases root size
Correct Answer: B
Explanation: Overexpression of DREB1A enhances tolerance to drought, high salinity, and cold in Arabidopsis.
13: What are key components in the physiological adaptation to drought in stems?
A: Stem elongation
B: Chlorophyll synthesis
C: Signal transport and hydraulic changes
D: Increased leaf number
Correct Answer: C
Explanation: Changes like signal transport and hydraulic modifications occur in stems as a drought response.
14: Plants from naturally arid areas can generally be classified into which category?
A: Rain-dependent plants
B: Drought-escaping plants
C: Shade plants
D: Aquatic plants
Correct Answer: B
Explanation: Drought-escaping plants are adapted to arid conditions, surviving only when moisture is sufficient.
15: What special type of metabolism allows some plants to minimize water loss during photosynthesis?
A: Aerobic metabolism
B: Gluconeogenesis
C: CAM metabolism
D: Sucrose synthesis
Correct Answer: C
Explanation: CAM metabolism lets plants take in carbon dioxide at night and store it as malic acid for daytime photosynthesis.
16: What characterizes drought-enduring plants?
A: Short life cycle
B: Deep root systems and evergreen nature
C: Bright flowers
D: Constant water requirement
Correct Answer: B
Explanation: Drought-enduring plants, or xerophytes, have extensive root systems and features enabling growth in extreme conditions.
17: What type of root adaptation aids drought-resisting plants?
A: Shallow, spreading roots
B: Extremely hairy roots
C: Deep, extensive roots
D: Water-absorbing surface hairs
Correct Answer: C
Explanation: Drought-resisting (succulent) plants often have deep root systems to maximize water absorption.
18: Which plant is known for its natural drought tolerance among ornamental plants?
A: Cactus
B: Petunia
C: Rose
D: Sunflower
Correct Answer: A
Explanation: Cacti are well-known for their natural adaptations to survive in drought conditions.
19: How does AREB1 function in drought response?
A: It deactivates stress genes
B: It activates dehydration-responsive genes
C: It reduces plant size
D: It increases flower production
Correct Answer: B
Explanation: AREB1 is a transcription factor that activates drought and stress-responsive genes.
20: What is the role of ROS-scavenging enzymes in drought tolerance?
A: They enhance leaf growth
B: They reduce oxidative stress
C: They increase root length
D: They produce more flowers
Correct Answer: B
Explanation: ROS-scavenging enzymes help limit oxidative damage during drought stress, contributing to plant survival.
21: How does an increase in root/shoot ratio help plants during a drought?
A: It boosts flowering
B: It increases water absorption
C: It reduces leaf production
D: It enhances seed formation
Correct Answer: B
Explanation: An increase in the root/shoot ratio allows plants to absorb more water from the soil during drought conditions.
22: What is a common structural adaptation of leaves in drought-tolerant plants?
A: Increased surface area
B: Numerous chloroplasts
C: Sunken stomata
D: Decreased color pigmentation
Correct Answer: C
Explanation: Sunken stomata help reduce water loss by decreasing the exposed surface area where evaporation can occur.
23: In drought research, which model plant has been predominantly studied?
A: Wheat
B: Arabidopsis
C: Oak
D: Pine
Correct Answer: B
Explanation: Arabidopsis has been widely used to study the molecular pathways and regulatory networks of drought tolerance.
24: What is the limitation of large-scale development of drought-resistant crops?
A: Limited genetic variability
B: High development costs
C: Slow growth rate
D: Low market demand
Correct Answer: B
Explanation: The high cost and time required (around USD 136 million over 13 years) limit the large-scale development of genetically modified drought-resistant crops.
25: What type of ornamental plant is being researched for abiotic stress resistance?
A: Dendrobium orchids
B: Marigolds
C: Drought-resistant Geraniums
D: Tulips
Correct Answer: C
Explanation: Research is ongoing to develop drought-resistant ornamental plants like Geraniums.
26: What international organization focuses on breeding drought-tolerant crop varieties?
A: NASA
B: WHO
C: CGIAR
D: OPEC
Correct Answer: C
Explanation: The Consultative Group on International Agricultural Research (CGIAR) is involved in developing drought-tolerant crop varieties.
27: Why is collaboration important in developing drought-tolerant crops?
A: It reduces the need for farmers
B: It decreases planting time
C: It shares the financial and technical burden
D: It makes plants grow faster
Correct Answer: C
Explanation: Collaborations share the financial and technical challenges, making it possible to develop drought-tolerant crops.
28: How does the plant hormone ABA contribute to drought tolerance?
A: Enhances flower production
B: Activates drought-response genes
C: Reduces leaf coloration
D: Inhibits root growth
Correct Answer: B
Explanation: ABA induces the expression of genes involved in the plant’s response to drought conditions.
29: What is a key feature of drought-evading plants?
A: They bloom during rainy seasons only
B: They grow continuously without water
C: They are underwater plants
D: They produce large seeds
Correct Answer: A
Explanation: Drought-evading plants restrict their growth and reproductive cycle to periods when moisture is available.
30: Why is stomatal closure important during drought?
A: It prevents water loss
B: It enhances photosynthesis
C: It increases oxygen intake
D: It accelerates plant growth
Correct Answer: A
Explanation: Stomatal closure conserves water by limiting transpiration during drought.
31: What is a common trait among drought-resisting succulent plants?
A: Large flowers
B: Water storage in leaves
C: High growth speed
D: Deep leaf color
Correct Answer: B
Explanation: Succulent plants such as cacti store water in their leaves to use during drought conditions.
32: Which plant’s leaf hair (trichomes) can absorb atmospheric water?
A: Sunflower
B: Scarlet globe mallow
C: Wheat
D: Rice
Correct Answer: B
Explanation: Trichomes on leaves of the scarlet globe mallow help absorb water from the atmosphere, aiding drought resistance.
33: What is an example of natural drought adaptations in plants?
A: Thick stem bark
B: Needle-like leaves
C: Deep root systems
D: Bright flower petals
Correct Answer: C
Explanation: Deep root systems are an adaptation to increase water uptake in arid conditions.
34: How does increased root growth help plants during drought?
A: By reducing leaf number
B: By enhancing water absorption
C: By increasing flower production
D: By reducing plant size
Correct Answer: B
Explanation: Enhanced root growth allows plants to access deeper water sources during drought periods.
35: Which transcription factor is induced by osmotic stress in plants?
A: Chloroplast
B: DREB2A
C: ATP synthase
D: Gibberellin
Correct Answer: B
Explanation: DREB2A is induced by osmotic stress and contributes to plant drought tolerance.
36: How do transgenic ornamental plants aid horticulture?
A: By improving stem structure
B: By resisting drought and frost
C: By increasing flower color variety
D: By reducing plant size
Correct Answer: B
Explanation: Transgenic ornamental plants with enhanced drought and frost resistance can grow in a wider range of environments.
37: Which of the following plants is known for its drought tolerance?
A: Rice
B: Cactus
C: Water lily
D: Bamboo
Correct Answer: B
Explanation: The cactus is well-adapted to drought conditions, with features like water storage in its tissues.
38: What challenge does the commercialization of drought-resistant crops face?
A: Low farmer interest
B: High development costs and patents
C: Shorter shelf life
D: Increased pest attacks
Correct Answer: B
Explanation: Commercializing drought-resistant crops is expensive and involves navigating multiple patents.
39: In what way is AREB/ABF regulated in plants?
A: By sunlight exposure
B: Via phosphorylation by SnRK2s
C: By reducing root growth
D: By chlorophyll concentration
Correct Answer: B
Explanation: AREB/ABFs are regulated by SnRK2s through phosphorylation, controlling stress response activities.
40: What project aims to evaluate drought tolerance in crops like rice and wheat?
A: NASA Space Crop Project
B: HeDWIC
C: CGIAR projects
D: National Wildlife Federation
Correct Answer: C
Explanation: The Consultative Group on International Agricultural Research (CGIAR) has projects focusing on evaluating drought tolerance in crops.
41: Which plant family has species that are notably drought-tolerant?
A: Liliaceae
B: Cactaceae
C: Poaceae
D: Rosaceae
Correct Answer: B
Explanation: Species from the Cactaceae family are notably drought-tolerant due to their adaptations to arid environments.
42: What physiological change occurs in leaves to reduce water loss during drought?
A: Increased leaf surface area
B: Stomatal opening
C: Skipped blooming
D: Reduction in leaf area
Correct Answer: D
Explanation: Reducing leaf area helps decrease water loss through transpiration in drought conditions.
43: Which soybean variety was developed for enhanced drought tolerance?
A: Sonatina
B: Estafeta
C: Miscanthus
D: Durango
Correct Answer: B
Explanation: Estafeta is a soybean variety developed for enhanced drought tolerance.
44: What inhibits shoot growth as a drought response in plants?
A: Increased leaf production
B: Improved water uptake
C: Reduced transpiration
D: Long-term drought conditions
Correct Answer: D
Explanation: Long-term drought conditions inhibit shoot growth to conserve water and resources.
45: Why is genetic modification important for developing drought-resistant crops?
A: It reduces root size
B: It increases plant height
C: It enhances water usage efficiency
D: It decreases seed size
Correct Answer: C
Explanation: Genetic modification allows for the development of crops that use water more efficiently, enhancing drought tolerance.
46: What is the significance of the Heat and Drought Wheat Improvement Consortium?
A: Reduces planting costs
B: Facilitates global research coordination on wheat adaptation
C: Increases chlorophyll production in wheat
D: Promotes rapid plant growth
Correct Answer: B
Explanation: The Heat and Drought Wheat Improvement Consortium (HeDWIC) aims to coordinate global wheat research for better adaptation to severe weather.
47: How do alterations in gene expression help plants during drought?
A: They increase flower size
B: They turn leaves dark green
C: They induce stress-response proteins
D: They halt photosynthesis
Correct Answer: C
Explanation: Alterations in gene expression induce the production of proteins that help the plant respond to stress and tolerate drought.
48: What is a characteristic of drought-escaping plants?
A: They have long lifespans
B: They grow only during periods of moisture
C: They require constant watering
D: They produce woody stems
Correct Answer: B
Explanation: Drought-escaping plants germinate and grow only when there is adequate moisture to complete their life cycle.
49: Which enzyme helps protect plants from oxidative stress during drought?
A: Amylase
B: Lipase
C: ROS-scavenging enzyme
D: Lactase
Correct Answer: C
Explanation: ROS-scavenging enzymes help reduce oxidative damage during drought, protecting the plant.
50: What is the role of transcription factors like NAC in drought tolerance?
A: They increase leaf size
B: They halt root growth
C: They enhance stress response and drought tolerance
D: They reduce seed production
Correct Answer: C
Explanation: Transcription factors such as NAC play roles in improving drought tolerance and stress response.
51: What is a common example of a structural adaptation in drought-resistant plants?
A: Large flowers
B: Reduced leaf number
C: Increased chlorophyll
D: Slender stems
Correct Answer: B
Explanation: Reduced leaf number minimizes water loss and is a common structural adaptation in drought-resistant plants.
52: How do abiotic stresses like drought induce gene expression changes?
A: By reducing leaf size
B: By increasing water uptake
C: By activating specific transcription factors
D: By altering cell wall structure
Correct Answer: C
Explanation: Abiotic stresses induce changes in gene expression by activating specific transcription factors that bind to stress-responsive elements.
53: Which type of plants restricts their growth to periods of moisture availability?
A: Aquatic plants
B: Epiphytes
C: Drought-evading non-succulent perennials
D: Alpine plants
Correct Answer: C
Explanation: Drought-evading non-succulent perennials grow only during moist periods to conserve water.
54: How do osmoprotectants help plants during drought?
A: They increase leaf area
B: They reduce root depth
C: They stabilize cellular structures
D: They promote rapid flowering
Correct Answer: C
Explanation: Osmoprotectants like sucrose, glycine, and proline stabilize cellular structures during drought, aiding in stress tolerance.
55: What type of metabolism is beneficial for drought-tolerant plants?
A: CAM metabolism
B: Aerobic metabolism
C: Anaerobic metabolism
D: Fermentation
Correct Answer: A
Explanation: Crassulacean Acid Metabolism (CAM) allows plants to open stomata at night, minimizing water loss during the day.
56: Which project collaborates globally to enhance drought tolerance in crops like soybeans and rice?
A: National Geographic Society
B: Embrapa
C: HeDWIC
D: Space Foundation
Correct Answer: B
Explanation: Embrapa collaborates on projects to enhance drought tolerance in crops such as soybeans and rice.
57: Which physiological response is a characteristic long-term drought response in plants?
A: Increase in shoot growth
B: Grain abortion
C: Leaf expansion
D: Increased transpiration
Correct Answer: B
Explanation: Grain abortion can occur as a long-term response to conserve resources during drought.
58: Why is there a significant lag in developing drought-resistant ornamental plants?
A: They have short lifespans
B: More focus is on drought tolerance in crop varieties
C: They require less water
D: They are less valuable economically
Correct Answer: B
Explanation: The lag is due to the primary focus on developing drought tolerance in essential crop varieties.
59: What is a key property of plants enabling them to maintain turgor pressure during drought?
A: Water storage in flowers
B: Increased leaf thickness
C: Sustained root growth
D: Colorful seeds
Correct Answer: C
Explanation: Sustained root growth helps absorb water and maintain turgor pressure during drought conditions.
60: How do genetic modifications improve agricultural crop varieties?
A: By making them more visually appealing
B: By prolonging their shelf life
C: By enhancing their drought tolerance and yield
D: By increasing their leaf size
Correct Answer: C
Explanation: Genetic modifications improve crop varieties by enhancing their tolerance to drought and increasing yield.