Q. What is the role of collenchyma cells in plants?
A.
Storage of starch
B.
Support in young stems and leaves
C.
Water transport
D.
Photosynthesis
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Solution
Collenchyma cells provide flexible support to young stems and leaves, allowing for growth and movement.
Correct Answer: B — Support in young stems and leaves
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Q. What is the role of cytokines in the immune response?
A.
To directly kill pathogens
B.
To signal and regulate immune cell activity
C.
To form antibodies
D.
To enhance phagocytosis
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Solution
Cytokines are signaling molecules that regulate and coordinate the immune response by influencing the activity of immune cells.
Correct Answer: B — To signal and regulate immune cell activity
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Q. What is the role of cytokinins in plant development?
A.
Promote leaf senescence
B.
Stimulate cell division
C.
Inhibit root growth
D.
Enhance photosynthesis
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Solution
Cytokinins are hormones that stimulate cell division and promote shoot development.
Correct Answer: B — Stimulate cell division
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Q. What is the role of cytokinins in plant growth?
A.
Promote root growth
B.
Stimulate cell division
C.
Inhibit leaf senescence
D.
All of the above
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Solution
Cytokinins stimulate cell division, promote root growth, and inhibit leaf senescence.
Correct Answer: D — All of the above
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Q. What is the role of dendritic cells in the immune response?
A.
To produce antibodies
B.
To present antigens to T cells
C.
To kill infected cells
D.
To secrete cytokines
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Solution
Dendritic cells are professional antigen-presenting cells that capture and present antigens to T cells, initiating the adaptive immune response.
Correct Answer: B — To present antigens to T cells
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Q. What is the role of dendritic cells in the immune system?
A.
Produce antibodies
B.
Present antigens to T cells
C.
Kill pathogens directly
D.
Secrete cytokines
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Solution
Dendritic cells are professional antigen-presenting cells that capture, process, and present antigens to T cells, initiating the adaptive immune response.
Correct Answer: B — Present antigens to T cells
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Q. What is the role of essential oils derived from plants in human health?
A.
Photosynthesis
B.
Antimicrobial properties
C.
Water absorption
D.
Nutrient storage
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Solution
Essential oils from plants often possess antimicrobial properties, making them useful in health and wellness.
Correct Answer: B — Antimicrobial properties
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Q. What is the role of essential oils in plants that can also benefit human health?
A.
Photosynthesis
B.
Defense against pests
C.
Water absorption
D.
Nutrient storage
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Solution
Essential oils help plants defend against pests and can have therapeutic effects in humans.
Correct Answer: B — Defense against pests
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Q. What is the role of essential oils in plants that can also have therapeutic effects on humans?
A.
Photosynthesis
B.
Defense mechanisms
C.
Water storage
D.
Nutrient absorption
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Solution
Essential oils help protect plants from pests and diseases, and can have therapeutic effects when used in aromatherapy.
Correct Answer: B — Defense mechanisms
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Q. What is the role of essential oils in plants?
A.
Photosynthesis
B.
Defense against herbivores
C.
Water storage
D.
Nutrient absorption
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Solution
Essential oils serve as a defense mechanism against herbivores and pathogens.
Correct Answer: B — Defense against herbivores
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Q. What is the role of fiber in the human digestive system?
A.
Provides energy
B.
Aids in digestion
C.
Increases fat absorption
D.
Stimulates bile production
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Solution
Fiber aids in digestion by promoting regular bowel movements and preventing constipation.
Correct Answer: B — Aids in digestion
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Q. What is the role of helper T cells in the immune response?
A.
Directly kill infected cells
B.
Stimulate B cells and cytotoxic T cells
C.
Produce antibodies
D.
Engulf pathogens
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Solution
Helper T cells play a crucial role in stimulating B cells to produce antibodies and activating cytotoxic T cells.
Correct Answer: B — Stimulate B cells and cytotoxic T cells
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Q. What is the role of histones in plant cells?
A.
Energy production
B.
DNA packaging
C.
Photosynthesis
D.
Cell division
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Solution
Histones are proteins that help package DNA into a compact, organized structure called chromatin.
Correct Answer: B — DNA packaging
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Q. What is the role of messenger RNA (mRNA) in gene expression?
A.
To replicate DNA
B.
To carry genetic information from DNA to ribosomes
C.
To form the structure of ribosomes
D.
To transport amino acids
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Solution
mRNA carries genetic information from DNA to ribosomes, where proteins are synthesized.
Correct Answer: B — To carry genetic information from DNA to ribosomes
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Q. What is the role of messenger RNA (mRNA)?
A.
To store genetic information
B.
To transport amino acids
C.
To carry genetic information from DNA to ribosomes
D.
To form the structure of ribosomes
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Solution
Messenger RNA (mRNA) carries genetic information from DNA to the ribosomes for protein synthesis.
Correct Answer: C — To carry genetic information from DNA to ribosomes
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Q. What is the role of monoclonal antibodies in biotechnology?
A.
To enhance photosynthesis
B.
To target specific cells in therapy
C.
To produce insulin
D.
To modify genetic sequences
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Solution
Monoclonal antibodies are designed to target specific cells, making them useful in therapies and diagnostics.
Correct Answer: B — To target specific cells in therapy
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Q. What is the role of mRNA in gene expression?
A.
To replicate DNA
B.
To transport amino acids
C.
To carry genetic information from DNA to ribosomes
D.
To form the ribosome structure
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Solution
mRNA carries the genetic information from DNA to the ribosomes for protein synthesis.
Correct Answer: C — To carry genetic information from DNA to ribosomes
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Q. What is the role of mutations in plant evolution?
A.
They are harmful and should be avoided
B.
They provide raw material for evolution
C.
They have no role in evolution
D.
They only occur in animals
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Solution
Mutations provide the raw material for evolution by introducing new genetic variations into a population.
Correct Answer: B — They provide raw material for evolution
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Q. What is the role of mycorrhizae in plant ecology?
A.
Water storage
B.
Nutrient absorption
C.
Photosynthesis
D.
Seed dispersal
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Solution
Mycorrhizae enhance nutrient absorption for plants, particularly phosphorus.
Correct Answer: B — Nutrient absorption
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Q. What is the role of mycorrhizae in plant growth?
A.
Water storage
B.
Nutrient absorption
C.
Photosynthesis
D.
Gas exchange
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Solution
Mycorrhizae enhance nutrient absorption, particularly phosphorus, from the soil.
Correct Answer: B — Nutrient absorption
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Q. What is the role of mycorrhizal fungi in plant growth?
A.
Photosynthesis
B.
Nutrient absorption
C.
Water storage
D.
Pollination
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Solution
Mycorrhizal fungi enhance nutrient absorption, particularly phosphorus, for plants.
Correct Answer: B — Nutrient absorption
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Q. What is the role of NADPH in photosynthesis?
A.
Energy storage
B.
Electron transport
C.
Carbon fixation
D.
Light absorption
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Solution
NADPH serves as an electron carrier in the light-independent reactions of photosynthesis.
Correct Answer: B — Electron transport
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Q. What is the role of phloem in plants?
A.
Transport of water
B.
Transport of sugars
C.
Support and structure
D.
Storage of nutrients
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Solution
Phloem is responsible for the transport of sugars and other metabolic products downward from the leaves.
Correct Answer: B — Transport of sugars
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Q. What is the role of phytochemicals in human health?
A.
Provide energy
B.
Enhance flavor
C.
Prevent disease
D.
Increase growth rate
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Solution
Phytochemicals are compounds in plants that can help prevent diseases.
Correct Answer: C — Prevent disease
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Q. What is the role of phytosterols found in plants regarding human health?
A.
Increase cholesterol levels
B.
Lower cholesterol levels
C.
Enhance flavor
D.
Promote growth
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Solution
Phytosterols can help lower cholesterol levels in humans by blocking the absorption of cholesterol in the intestines.
Correct Answer: B — Lower cholesterol levels
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Q. What is the role of phytosterols in human health?
A.
Increase blood sugar
B.
Lower cholesterol
C.
Enhance digestion
D.
Boost immunity
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Solution
Phytosterols are known to lower cholesterol levels in the body.
Correct Answer: B — Lower cholesterol
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Q. What is the role of pollinators in plant reproduction?
A.
To provide water to the plants
B.
To assist in seed dispersal
C.
To transfer pollen from male to female structures
D.
To enhance photosynthesis
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Solution
Pollinators transfer pollen from the male anthers to the female stigma, facilitating fertilization.
Correct Answer: C — To transfer pollen from male to female structures
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Q. What is the role of pollinators in the evolution of flowering plants?
A.
They reduce genetic diversity
B.
They facilitate cross-pollination
C.
They increase competition
D.
They have no role
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Solution
Pollinators facilitate cross-pollination, which enhances genetic diversity and can lead to evolutionary adaptations in flowering plants.
Correct Answer: B — They facilitate cross-pollination
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Q. What is the role of restriction enzymes in molecular biology?
A.
To cut DNA at specific sequences
B.
To synthesize RNA
C.
To amplify DNA
D.
To repair DNA
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Solution
Restriction enzymes cut DNA at specific sequences, which is essential for cloning and recombinant DNA technology.
Correct Answer: A — To cut DNA at specific sequences
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Q. What is the role of Rhizobium bacteria in legume plants?
A.
Decomposing organic matter
B.
Fixing atmospheric nitrogen
C.
Promoting root growth
D.
Producing secondary metabolites
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Solution
Rhizobium bacteria form nodules on legume roots and fix atmospheric nitrogen, benefiting the plant.
Correct Answer: B — Fixing atmospheric nitrogen
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