Q31. What is the role of stomata in plants?
a) Absorption of sunlight
b) Regulation of water loss and gas exchange
c) Production of carbohydrates
d) Root anchorage
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Correct Answer: b) Regulation of water loss and gas exchange
Explanation: Stomata are tiny pores found on the surface of leaves and stems in plants. Their primary function is to regulate water loss by controlling the exchange of gases, such as oxygen and carbon dioxide, between the plant and the surrounding environment. Stomata open and close in response to environmental cues, such as light intensity and humidity, to prevent excessive water loss while allowing for photosynthesis and gas exchange to occur.
Q32. Which of the following is NOT a function of the skeletal system?
a) Protection of internal organs
b) Production of blood cells
c) Regulation of body temperature
d) Facilitation of movement
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Correct Answer: c) Regulation of body temperature
Explanation: While the skeletal system plays a role in supporting and protecting the body, producing blood cells in bone marrow, and facilitating movement by providing attachment sites for muscles, it is not directly involved in the regulation of body temperature. Body temperature regulation primarily involves the integumentary system (skin), cardiovascular system, and nervous system.
Q33. What is the purpose of meiosis in sexually reproducing organisms?
a) To produce genetically identical daughter cells
b) To produce gametes with half the number of chromosomes
c) To repair damaged DNA
d) To generate energy for cellular processes
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Correct Answer: b) To produce gametes with half the number of chromosomes
Explanation: Meiosis is a type of cell division that occurs in sexually reproducing organisms to produce gametes, such as sperm and eggs. Its primary purpose is to reduce the chromosome number by half, ensuring that when gametes fuse during fertilization, the resulting zygote has the correct chromosome number (diploid). This process also introduces genetic variation through crossing over and independent assortment.
Q34. What is the function of the cerebellum in the brain?
a) Regulation of heart rate and breathing
b) Control of voluntary movements and coordination
c) Processing of sensory information
d) Memory formation and learning
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Correct Answer: b) Control of voluntary movements and coordination
Explanation: The cerebellum is a region of the brain located at the back of the skull, beneath the cerebrum. Its primary function is to coordinate and regulate voluntary movements, balance, and posture. It receives information from sensory systems, such as the proprioceptive organs in muscles and joints, and integrates this information to fine-tune motor commands generated by the cerebral cortex, ensuring smooth and coordinated movements.
Q35. Which of the following is NOT a characteristic of prokaryotic cells?
a) Presence of a nucleus
b) Lack of membrane-bound organelles
c) Presence of ribosomes
d) Presence of a cell wall
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Correct Answer: a) Presence of a nucleus
Explanation: Prokaryotic cells, which include bacteria and archaea, lack a true nucleus and other membrane-bound organelles found in eukaryotic cells. Instead, their genetic material is typically organized in a single circular chromosome located in the nucleoid region. While prokaryotic cells do contain ribosomes, cell walls, and other cellular structures, they do not have a nucleus enclosed within a nuclear membrane.
Q36. What is the function of the enzyme amylase in the digestive system?
a) Breakdown of lipids
b) Breakdown of proteins
c) Breakdown of carbohydrates
d) Absorption of nutrients
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Correct Answer: c) Breakdown of carbohydrates
Explanation: Amylase is an enzyme produced by the salivary glands and pancreas that catalyzes the breakdown of complex carbohydrates, such as starch and glycogen, into simpler sugars like maltose and glucose. This process begins in the mouth, where salivary amylase starts the digestion of carbohydrates, and continues in the small intestine with pancreatic amylase.
Q37. Which of the following is NOT a function of the respiratory system?
a) Exchange of gases
b) Regulation of blood pH
c) Production of hormones
d) Filtering of air
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Correct Answer: c) Production of hormones
Explanation: While the respiratory system plays a crucial role in the exchange of gases (oxygen and carbon dioxide) between the body and the environment, regulation of blood pH through the control of carbon dioxide levels, and filtering of air to remove particulate matter and pathogens, it is not directly involved in the production of hormones. Hormone production primarily occurs in endocrine glands such as the pituitary, thyroid, and adrenal glands.
Q38. What is the main function of the adrenal glands?
a) Regulation of blood glucose levels
b) Production of reproductive hormones
c) Control of calcium levels in the blood
d) Maintenance of fluid balance
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Correct Answer: a) Regulation of blood glucose levels
Explanation: The adrenal glands, located above the kidneys, produce hormones that play essential roles in regulating various physiological processes. One of their main functions is to produce cortisol, a hormone involved in the body’s response to stress and regulation of blood glucose levels. Additionally, the adrenal glands produce aldosterone, which helps regulate electrolyte balance and blood pressure.
Q39. Which of the following is NOT a type of ecological relationship between organisms?
a) Predation
b) Competition
c) Cooperation
d) Fertilization
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Correct Answer: d) Fertilization
Explanation: Ecological relationships refer to interactions between different organisms within ecosystems. Predation involves one organism (predator) consuming another (prey) for food, competition occurs when organisms compete for limited resources, and cooperation involves mutually beneficial interactions between organisms. Fertilization, however, is a reproductive process involving the fusion of gametes to form a zygote and is not considered an ecological relationship.
Q40. What is the function of the nephrons in the kidneys?
a) Regulation of blood pressure
b) Filtration of blood and urine formation
c) Production of red blood cells
d) Digestion of proteins
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Correct Answer: b) Filtration of blood and urine formation
Explanation: Nephrons are the functional units of the kidneys responsible for filtering blood and forming urine. Each nephron consists of a renal corpuscle (glomerulus and Bowman’s capsule) and renal tubules, where blood is filtered to remove waste products, excess ions, and water. The filtered fluid, known as filtrate, is then processed and modified as it passes through the renal tubules, ultimately forming urine.