Q. What is the role of NADP+ in photosynthesis? (2021)
A.
Energy storage
B.
Electron carrier
C.
Carbon source
D.
Light absorber
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Solution
NADP+ acts as an electron carrier, becoming reduced to NADPH during the light-dependent reactions.
Correct Answer: B — Electron carrier
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Q. What is the role of neurotransmitters in neural communication? (2019)
A.
To generate action potentials
B.
To transmit signals across the synapse
C.
To maintain resting membrane potential
D.
To insulate the axon
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Solution
Neurotransmitters are chemicals that transmit signals across the synapse from one neuron to another.
Correct Answer: B — To transmit signals across the synapse
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Q. What is the role of neurotransmitters in the nervous system? (2019)
A.
To transmit electrical impulses along the axon
B.
To facilitate communication between neurons
C.
To protect the neuron from pathogens
D.
To store genetic information
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Solution
Neurotransmitters are chemicals that transmit signals across a synapse from one neuron to another.
Correct Answer: B — To facilitate communication between neurons
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Q. What is the role of nitrogen oxides in the environment? (2021)
A.
Ozone formation
B.
Greenhouse effect
C.
Acid rain
D.
All of the above
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Solution
Nitrogen oxides contribute to ozone formation, the greenhouse effect, and are a precursor to acid rain.
Correct Answer: D — All of the above
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Q. What is the role of nucleotides in cells? (2019)
A.
Energy carriers
B.
Building blocks of proteins
C.
Genetic information carriers
D.
Structural components
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Solution
Nucleotides are the building blocks of nucleic acids and carry genetic information.
Correct Answer: C — Genetic information carriers
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Q. What is the role of oxygen in aerobic respiration? (2019)
A.
To produce glucose
B.
To act as an electron acceptor
C.
To release energy
D.
To absorb carbon dioxide
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Solution
Oxygen acts as the final electron acceptor in the electron transport chain during aerobic respiration.
Correct Answer: B — To act as an electron acceptor
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Q. What is the role of oxytocin in the human body? (2020)
A.
Regulates metabolism
B.
Stimulates uterine contractions
C.
Increases blood sugar
D.
Promotes water retention
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Solution
Oxytocin is a hormone that stimulates uterine contractions during childbirth and is also involved in social bonding.
Correct Answer: B — Stimulates uterine contractions
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Q. What is the role of parathyroid hormone (PTH)? (2020)
A.
Increase blood calcium levels
B.
Decrease blood calcium levels
C.
Regulate blood sugar
D.
Stimulate metabolism
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Solution
Parathyroid hormone (PTH) increases blood calcium levels by stimulating the release of calcium from bones and increasing calcium absorption in the intestines.
Correct Answer: A — Increase blood calcium levels
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Q. What is the role of phytoplankton in the carbon cycle? (2020)
A.
Carbon storage
B.
Carbon release
C.
Carbon transformation
D.
Carbon transportation
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Solution
Phytoplankton absorb carbon dioxide during photosynthesis, playing a crucial role in carbon storage in the ocean.
Correct Answer: A — Carbon storage
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Q. What is the role of phytoplankton in the environment? (2019)
A.
Carbon dioxide production
B.
Oxygen production
C.
Soil erosion
D.
Water pollution
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Solution
Phytoplankton are crucial for oxygen production through photosynthesis and play a significant role in the carbon cycle.
Correct Answer: B — Oxygen production
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Q. What is the role of plasmids in genetic engineering? (2019)
A.
To provide energy
B.
To serve as vectors for gene cloning
C.
To synthesize proteins
D.
To degrade DNA
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Solution
Plasmids are small circular DNA molecules that can replicate independently and are commonly used as vectors to transfer genes into host cells in genetic engineering.
Correct Answer: B — To serve as vectors for gene cloning
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Q. What is the role of platelets in the circulatory system? (2023)
A.
Transporting oxygen
B.
Clotting blood
C.
Fighting infections
D.
Transporting carbon dioxide
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Solution
Platelets, or thrombocytes, are essential for blood clotting, helping to prevent excessive bleeding when injuries occur.
Correct Answer: B — Clotting blood
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Q. What is the role of preservatives in food? (2020)
A.
Enhance flavor
B.
Increase shelf life
C.
Add color
D.
Improve texture
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Solution
Preservatives are added to food to prevent spoilage and increase shelf life by inhibiting the growth of microorganisms.
Correct Answer: B — Increase shelf life
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Q. What is the role of producers in an ecosystem? (2021)
A.
They consume other organisms.
B.
They decompose organic matter.
C.
They convert solar energy into chemical energy.
D.
They compete for resources.
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Solution
Producers convert solar energy into chemical energy through photosynthesis, forming the base of the food chain.
Correct Answer: C — They convert solar energy into chemical energy.
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Q. What is the role of RNA polymerase in transcription? (2021)
A.
To synthesize DNA
B.
To synthesize RNA
C.
To unwind DNA
D.
To splice RNA
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Solution
RNA polymerase is responsible for synthesizing RNA from a DNA template during transcription.
Correct Answer: B — To synthesize RNA
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Q. What is the role of sepals in a flower? (2022)
A.
Attract pollinators
B.
Protect the flower bud
C.
Produce pollen
D.
Support the ovary
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Solution
Sepals protect the flower bud before it opens and can also support the flower.
Correct Answer: B — Protect the flower bud
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Q. What is the role of sulfur in plants? (2023)
A.
Protein synthesis
B.
Photosynthesis
C.
Water uptake
D.
Cell division
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Solution
Sulfur is essential for the synthesis of amino acids and proteins, playing a critical role in plant metabolism.
Correct Answer: A — Protein synthesis
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Q. What is the role of synovial fluid in joints? (2022)
A.
Provides nutrients to cartilage
B.
Acts as a lubricant
C.
Absorbs shock
D.
All of the above
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Solution
Synovial fluid provides lubrication, nutrients, and shock absorption in synovial joints.
Correct Answer: D — All of the above
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Q. What is the role of tendons in the muscular system? (2023)
A.
Connect muscles to bones
B.
Connect bones to bones
C.
Store energy
D.
Facilitate blood flow
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Solution
Tendons connect muscles to bones, allowing for the transfer of force and movement.
Correct Answer: A — Connect muscles to bones
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Q. What is the role of the cambium in plants? (2021)
A.
Photosynthesis
B.
Growth in thickness
C.
Water transport
D.
Food storage
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Solution
The cambium is a layer of meristematic tissue that contributes to the growth in thickness (secondary growth) of stems and roots.
Correct Answer: B — Growth in thickness
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Q. What is the role of the cell membrane? (2021)
A.
Energy production
B.
Transport of substances
C.
Protein synthesis
D.
Photosynthesis
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Solution
The cell membrane regulates the transport of substances in and out of the cell.
Correct Answer: B — Transport of substances
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Q. What is the role of the filament in a flower? (2022)
A.
To support the anther
B.
To attract pollinators
C.
To produce ovules
D.
To receive pollen
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Solution
The filament is the stalk that supports the anther, which produces pollen.
Correct Answer: A — To support the anther
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Q. What is the role of the loop of Henle in the nephron? (2023)
A.
Reabsorption of water
B.
Secretion of urea
C.
Filtration of blood
D.
Regulation of pH
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Solution
The loop of Henle plays a crucial role in the reabsorption of water and salts, helping to concentrate urine.
Correct Answer: A — Reabsorption of water
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Q. What is the role of the lymphatic system in the human body? (2023)
A.
Transporting oxygen
B.
Removing waste products
C.
Regulating blood pressure
D.
Transporting lymph and immune cells
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Solution
The lymphatic system is responsible for transporting lymph, which contains immune cells, and helps in the removal of waste products from tissues.
Correct Answer: D — Transporting lymph and immune cells
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Q. What is the role of the M checkpoint in the cell cycle? (2023)
A.
To check for DNA damage
B.
To ensure chromosomes are properly aligned
C.
To initiate DNA replication
D.
To signal the end of cytokinesis
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Solution
The M checkpoint ensures that all chromosomes are properly aligned at the metaphase plate before the cell proceeds to anaphase.
Correct Answer: B — To ensure chromosomes are properly aligned
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Q. What is the role of the ovary in the female reproductive system? (2021)
A.
Production of sperm
B.
Production of eggs
C.
Fertilization of eggs
D.
Nourishment of the fetus
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Solution
The ovary's primary role in the female reproductive system is the production of eggs (ova) which are necessary for reproduction.
Correct Answer: B — Production of eggs
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Q. What is the role of the pancreas in digestion? (2023)
A.
Secretes bile
B.
Produces digestive enzymes
C.
Absorbs nutrients
D.
Stores food
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Solution
The pancreas produces digestive enzymes that help in the digestion of carbohydrates, proteins, and fats.
Correct Answer: B — Produces digestive enzymes
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Q. What is the role of the plasma membrane? (2021)
A.
Energy production
B.
Transport of substances
C.
Protein synthesis
D.
Genetic information storage
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Solution
The plasma membrane regulates the transport of substances in and out of the cell.
Correct Answer: B — Transport of substances
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Q. What is the role of the spleen in the human body? (2021)
A.
Production of insulin
B.
Filtration of blood
C.
Digestion of food
D.
Respiration
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Solution
The spleen plays a crucial role in filtering blood and removing old or damaged red blood cells.
Correct Answer: B — Filtration of blood
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Q. What is the role of the stigma in a flower? (2019)
A.
To produce ovules
B.
To receive pollen
C.
To support the flower
D.
To attract insects
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Solution
The stigma is the part of the pistil that receives pollen during fertilization.
Correct Answer: B — To receive pollen
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