Biology
Q. What is the result of cytokinesis in animal cells? (2020)
A.
Formation of a cell plate
B.
Formation of two daughter cells
C.
Replication of DNA
D.
Separation of sister chromatids
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Solution
Cytokinesis results in the physical separation of the cytoplasm, leading to the formation of two daughter cells.
Correct Answer: B — Formation of two daughter cells
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Q. What is the role of Agrobacterium tumefaciens in biotechnology? (2021)
A.
Gene delivery
B.
Protein synthesis
C.
Cell division
D.
DNA replication
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Solution
Agrobacterium tumefaciens is used as a vector for gene delivery in plant biotechnology.
Correct Answer: A — Gene delivery
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Q. What is the role of aldosterone in the body? (2021)
A.
Increase blood glucose
B.
Regulate sodium and potassium levels
C.
Stimulate milk production
D.
Enhance immune response
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Solution
Aldosterone is a hormone produced by the adrenal cortex that helps regulate sodium and potassium levels, thus influencing blood pressure.
Correct Answer: B — Regulate sodium and potassium levels
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Q. What is the role of biopesticides in agriculture? (2021)
A.
Increase soil fertility
B.
Control pest populations
C.
Enhance crop yield
D.
Improve water retention
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Solution
Biopesticides are used to control pest populations in an environmentally friendly manner, reducing the reliance on chemical pesticides.
Correct Answer: B — Control pest populations
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Q. What is the role of calcium ions in muscle contraction? (2022)
A.
To provide energy
B.
To bind to troponin
C.
To stimulate nerve impulses
D.
To form cross-bridges
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Solution
Calcium ions bind to troponin, causing a conformational change that allows myosin to bind to actin.
Correct Answer: B — To bind to troponin
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Q. What is the role of chloroplasts in plant cells? (2021)
A.
Respiration
B.
Photosynthesis
C.
Digestion
D.
Reproduction
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Solution
Chloroplasts are responsible for photosynthesis, converting light energy into chemical energy.
Correct Answer: B — Photosynthesis
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Q. What is the role of condoms in reproductive health? (2021)
A.
To enhance pleasure
B.
To prevent pregnancy and STIs
C.
To increase fertility
D.
To promote sexual activity
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Solution
Condoms are used to prevent both pregnancy and the transmission of sexually transmitted infections (STIs).
Correct Answer: B — To prevent pregnancy and STIs
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Q. What is the role of cyclins in the cell cycle? (2019)
A.
To inhibit cell division
B.
To promote apoptosis
C.
To regulate the cell cycle
D.
To repair DNA
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Solution
Cyclins are proteins that regulate the progression of the cell cycle by activating cyclin-dependent kinases (CDKs).
Correct Answer: C — To regulate the cell cycle
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Q. What is the role of DNA ligase in recombinant DNA technology? (2021)
A.
To cut DNA
B.
To join DNA fragments
C.
To replicate DNA
D.
To transcribe RNA
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Solution
DNA ligase is an enzyme that joins DNA fragments together, which is crucial for creating recombinant DNA molecules.
Correct Answer: B — To join DNA fragments
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Q. What is the role of DNA polymerase? (2021)
A.
Transcription
B.
Replication
C.
Translation
D.
Repair
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Solution
DNA polymerase is an enzyme that synthesizes new DNA strands during replication.
Correct Answer: B — Replication
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Q. What is the role of genetic drift in evolution? (1930)
A.
It increases genetic variation
B.
It leads to random changes in allele frequencies
C.
It promotes adaptation to the environment
D.
It is a form of natural selection
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Solution
Genetic drift is a mechanism of evolution that leads to random changes in allele frequencies in a population, particularly in small populations.
Correct Answer: B — It leads to random changes in allele frequencies
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Q. What is the role of genetically modified organisms (GMOs) in agriculture? (2022)
A.
Increase biodiversity
B.
Reduce crop yield
C.
Enhance resistance to pests
D.
Decrease nutritional value
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Solution
GMOs are engineered to enhance resistance to pests, thereby increasing crop yield.
Correct Answer: C — Enhance resistance to pests
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Q. What is the role of glucagon in the body? (2021)
A.
Increase blood sugar levels
B.
Decrease blood sugar levels
C.
Stimulate growth
D.
Regulate metabolism
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Solution
Glucagon is a hormone produced by the pancreas that raises blood sugar levels by promoting the conversion of glycogen to glucose in the liver.
Correct Answer: A — Increase blood sugar levels
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Q. What is the role of hemoglobin in respiration? (2019)
A.
Transporting oxygen
B.
Filtering air
C.
Regulating pH
D.
Producing carbon dioxide
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Solution
Hemoglobin in red blood cells binds to oxygen in the lungs and transports it to tissues throughout the body.
Correct Answer: A — Transporting oxygen
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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 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 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 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 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 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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