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#1 An organism described as "heliotropic" has a tendancy to move towards which of these things?
Explanation
Heliotropism is the directional growth or movement of an organism in response to sunlight. Plants like sunflowers exhibit heliotropism by following the sun's path across the sky to maximize photosynthesis. The term comes from Greek 'helios' (sun) and 'tropism' (turning).
#2 Which of these choices is not one of the phases of mitosis?
Explanation
Diplophase is not a phase of mitosis. The four main phases of mitosis are Prophase, Metaphase, Anaphase, and Telophase (PMAT). Diplophase refers to the diploid stage in an organism's life cycle, not a specific mitotic phase.
#3 The planet Mars has two moons orbiting it.
Explanation
Mars has two small moons: Phobos and Deimos, named after the Greek gods of fear and panic. Both are irregularly shaped and thought to be captured asteroids. Phobos is the larger and closer moon, while Deimos is smaller and more distant.
#4 Where did the dog breed "Chihuahua" originate?
Explanation
The Chihuahua breed originated in Mexico and is named after the Mexican state of Chihuahua. They are descendants of the Techichi, a companion dog favored by the Toltec civilization. Chihuahuas are the world's smallest dog breed.
#5 The human right lung has how many lobes?
Explanation
The human right lung has three lobes: upper, middle, and lower. The left lung has only two lobes (upper and lower) to make room for the heart. The lobes are separated by fissures and help compartmentalize lung function.
#6 Pneumonoultramicroscopicsilicovolcanoconiosis is a synonym for the disease known as silicosis.
Explanation
Pneumonoultramicroscopicsilicovolcanoconiosis is indeed a technical term for silicosis, a lung disease caused by inhaling fine silica dust. This 45-letter word was coined as the longest word in English, though it's rarely used in medical practice.
#7 What mineral has the lowest number on the Mohs scale?
Explanation
Talc ranks 1 on the Mohs hardness scale, making it the softest mineral. The scale ranges from 1 (softest) to 10 (hardest), with diamond at 10, quartz at 7, and gypsum at 2. Talc is so soft it can be scratched with a fingernail.
#8 How old is the universe?
Explanation
Current scientific estimates place the age of the universe at approximately 13.8 billion years, based on observations of cosmic microwave background radiation and the expansion rate of the universe. This date marks the time since the Big Bang.
#9 Sugar contains fat.
Explanation
Sugar does not contain fat. Sugar is a carbohydrate composed of carbon, hydrogen, and oxygen atoms. Fats (lipids) are a different macronutrient with a different chemical structure containing fatty acids and glycerol.
#10 Which part of the body does glaucoma affect?
Explanation
Glaucoma is a group of eye diseases that damage the optic nerve, often due to increased pressure within the eye. It's a leading cause of blindness worldwide and is often called the 'silent thief of sight' because it can progress without symptoms.
#11 What is the chemical symbol for lead?
Explanation
Lead has the chemical symbol 'Pb' from its Latin name 'plumbum.' Lead is a heavy metal that was historically used in pipes and paint but is now known to be toxic, especially to children's developing nervous systems.
#12 The Sun consists of mostly which two elements?
Explanation
The Sun is composed of approximately 73% hydrogen and 25% helium by mass. Nuclear fusion in the Sun's core converts hydrogen into helium, releasing enormous amounts of energy that provide light and heat to our solar system.
#13 Approximately what percentage of Earth's atmosphere is Oxygen?
Explanation
Oxygen makes up approximately 21% of Earth's atmosphere by volume. Nitrogen comprises about 78%, while the remaining 1% consists of argon, carbon dioxide, and trace gases. This oxygen level is maintained by photosynthesis from plants and marine organisms.
#14 When was the first mammal successfully cloned?
Explanation
Dolly the sheep became the first mammal cloned from an adult somatic cell in 1996 at the Roslin Institute in Scotland. This breakthrough in reproductive cloning used nuclear transfer technology and sparked worldwide discussions about the ethics and potential of cloning.
#15 Which of the following men does not have a chemical element named after him?
Explanation
Sir Isaac Newton does not have an element named after him. Einstein has Einsteinium (Es), Bohr has Bohrium (Bh), and Fermi has Fermium (Fm). Many transuranic elements have been named after famous scientists who contributed to physics and chemistry.
#16 "Tachycardia" or "Tachyarrhythmia" refers to a resting heart-rate near or over 100 BPM.
Explanation
Tachycardia is defined as a resting heart rate over 100 beats per minute in adults. It can be caused by various factors including stress, medication, medical conditions, or abnormal electrical activity in the heart. Normal resting heart rate is typically 60-100 BPM.
#17 Which of these two plates are best know for forming earthquakes and tsunami's?
Explanation
Convergent plate boundaries involving oceanic crust are most associated with major earthquakes and tsunamis. When oceanic plates collide or subduct, they can cause powerful underwater earthquakes that displace large volumes of water, generating tsunamis.
#18 Which planet in the Solar System is the closest to the Sun?
Explanation
Mercury is the closest planet to the Sun, orbiting at an average distance of about 58 million kilometers (36 million miles). Despite being closest to the Sun, Mercury is not the hottest planet due to its lack of atmosphere to trap heat.
#19 How many officially recognized dwarf planets in the solar system are named after Polynesian deities?
Explanation
Two officially recognized dwarf planets are named after Polynesian deities: Haumea (Hawaiian goddess of childbirth) and Makemake (Easter Island creator deity). The other dwarf planets are Pluto (Roman god), Ceres (Roman goddess), and Eris (Greek goddess).
#20 After which Danish city is the 72th element on the periodic table named?
Explanation
Element 72, Hafnium (Hf), is named after Hafnia, the Latin name for Copenhagen, Denmark. It was discovered by Dirk Coster and George de Hevesy in Copenhagen in 1923. Hafnium is a transition metal used in nuclear reactor control rods.
#21 Which portion of the Marijuana plant produces the psychoactive substance known as THC?
Explanation
THC (tetrahydrocannabinol) is primarily produced in the trichomes of female cannabis flowers (buds). These resinous structures contain the highest concentrations of cannabinoids. Male flowers and other plant parts contain much lower levels of THC.
#22 Where did the Great Storm of 1987 make landfall at, first?
Explanation
The Great Storm of 1987 first made landfall in Cornwall, southwestern England, during the night of October 15-16, 1987. This extratropical cyclone then moved northeast across southern England, causing widespread damage and killing 18 people.
#23 Male pandas do handstands while urinating on trees.
Explanation
Male giant pandas do indeed perform handstands while urinating on trees to mark their territory. This behavior allows them to spray their scent higher up on the tree, making their territorial markers more noticeable to other pandas.
#24 Myopia is the scientific term for which condition?
Explanation
Myopia is the scientific term for nearsightedness or shortsightedness, where distant objects appear blurry while close objects are seen clearly. This occurs when the eyeball is too long or the cornea is too curved, causing light to focus in front of the retina.
#25 What is the atomic number of the element Strontium?
Explanation
Strontium has the atomic number 38, meaning it has 38 protons in its nucleus. It's an alkaline earth metal that burns with a bright red flame and is used in fireworks to produce red colors. Strontium-90 is a radioactive isotope produced in nuclear fission.
#26 In Chemistry, how many isomers does Butanol (C4H9OH) have?
Explanation
Butanol (C₄H₉OH) has four structural isomers: 1-butanol (n-butanol), 2-butanol (sec-butanol), isobutanol (2-methyl-1-propanol), and tert-butanol (2-methyl-2-propanol). These isomers differ in the arrangement of their carbon skeleton and hydroxyl group position.
#27 In human biology, a circadium rhythm relates to a period of roughly how many hours?
Explanation
A circadian rhythm (note: the question has a typo - should be 'circadian') is a biological cycle that occurs roughly every 24 hours. These internal biological clocks regulate sleep-wake cycles, hormone production, and many other physiological processes in response to light and dark.
#28 Which desert is the only desert in the world where the "Saguaro" cactus grows indigenously?
Explanation
The Saguaro cactus grows exclusively in the Sonoran Desert, which spans parts of Arizona, California, and northwestern Mexico. These iconic cacti can live over 150 years and grow up to 40 feet tall, making them symbols of the American Southwest.
#29 Which enzyme is responsible for breaking down lactose in the human digestive system?
Explanation
Lactase is the enzyme that breaks down lactose (milk sugar) into glucose and galactose in the small intestine. People with lactose intolerance have reduced lactase production, making it difficult to digest dairy products. Amylase breaks down starch, pepsin breaks down proteins, and lipase breaks down fats.
#30 In the periodic table, Potassium's symbol is the letter K.
Explanation
Potassium's chemical symbol is indeed 'K,' derived from its Latin name 'kalium.' Potassium is an essential electrolyte for human health, crucial for nerve function, muscle contractions, and maintaining proper heart rhythm.
#31 What is the half-life of Uranium-235?
Explanation
Uranium-235 has a half-life of approximately 703.8 million years. This means that in that time period, half of any given sample will decay into other elements. U-235 is the fissile isotope used in nuclear reactors and weapons.
#32 Like with the Neanderthals, Homo sapiens sapiens also interbred with the Denisovans.
Explanation
Genetic evidence shows that modern humans interbred with both Neanderthals and Denisovans. People of Melanesian descent carry up to 6% Denisovan DNA, while most non-African populations carry 1-4% Neanderthal DNA.
#33 What does the yellow diamond on the NFPA 704 fire diamond represent?
Explanation
In the NFPA 704 hazard identification system, the yellow diamond represents chemical reactivity or instability. Blue indicates health hazards, red indicates flammability, and white indicates special hazards. Numbers 0-4 indicate increasing hazard levels.
#34 What is the unit of electrical capacitance?
Explanation
The farad (F) is the unit of electrical capacitance, named after Michael Faraday. One farad is the capacitance that stores one coulomb of charge with one volt of potential difference. Gauss measures magnetic field, Henry measures inductance, and Watt measures power.
#35 The "Tibia" is found in which part of the body?
Explanation
The tibia, also known as the shin bone, is the larger of the two bones in the lower leg. It's the second longest bone in the human body after the femur and bears most of the body's weight when standing and walking.
#36 What is the lowest layer of the Earth's atmosphere named?
Explanation
The troposphere is the lowest layer of Earth's atmosphere, extending from the surface to about 8-15 km altitude. This is where weather occurs and where most commercial aircraft fly. It contains about 75% of the atmosphere's mass.
#37 Which chemical element has the lowest boiling point?
Explanation
Helium has the lowest boiling point of all elements at -268.9°C (-452°F). This extremely low boiling point makes liquid helium useful for cooling superconducting magnets in MRI machines and particle accelerators.
#38 Who developed the first successful polio vaccine in the 1950s?
Explanation
Jonas Salk developed the first successful polio vaccine in 1955. His inactivated poliovirus vaccine (IPV) dramatically reduced polio cases worldwide. Albert Sabin later developed an oral polio vaccine (OPV). Enders, Weller, and Robbins won the Nobel Prize for growing poliovirus in tissue culture.
#39 The medial meniscus forms which part of what joint in the human body?
Explanation
The medial meniscus is a C-shaped piece of cartilage that cushions the knee joint between the femur and tibia. It acts as a shock absorber and helps distribute weight across the joint. Meniscus tears are common sports injuries.
#40 Down Syndrome is usually caused by an extra copy of which chromosome?
Explanation
Down Syndrome is caused by trisomy 21, meaning there are three copies of chromosome 21 instead of the normal two. This extra genetic material causes the characteristic features and intellectual disability associated with the condition.
#41 The humerus, paired radius, and ulna come together to form what joint?
Explanation
The elbow joint is formed by the articulation of the humerus (upper arm bone) with the radius and ulna (forearm bones). This hinge joint allows for flexion and extension of the forearm, as well as rotation of the forearm.
#42 What medication was once commonly used as rat poison?
Explanation
Coumadin (warfarin) was originally developed as rat poison because it prevents blood clotting, causing internal bleeding. In controlled doses, it's now used as an anticoagulant medication to prevent blood clots in humans with certain medical conditions.
#43 The moons, Miranda, Ariel, Umbriel, Titania and Oberon orbit which planet?
Explanation
These five moons are the largest satellites of Uranus, named after characters from Shakespeare's plays. Uranus has 27 known moons in total, with these five being discovered before the Voyager 2 flyby in 1986 revealed many smaller moons.
#44 Which of these stars is the largest?
Explanation
UY Scuti is currently considered the largest known star by radius, with a radius approximately 1,700 times that of our Sun. If placed at the center of our solar system, it would extend beyond Jupiter's orbit. VY Canis Majoris was previously thought to be the largest but has been revised to be smaller than UY Scuti.
#45 Sound can travel through a vacuum.
Explanation
Sound cannot travel through a vacuum because it requires a medium (like air, water, or solid materials) to propagate. Sound waves are mechanical vibrations that need molecules to transfer energy from one location to another. In the vacuum of space, there are no molecules to carry sound waves.
#46 What is radiation measured in?
Explanation
The Gray (Gy) is the SI unit for measuring absorbed radiation dose, defined as one joule of energy absorbed per kilogram of matter. Other radiation units include the Sievert (Sv) for equivalent dose and the Becquerel (Bq) for radioactivity. Watt measures power, decibel measures sound intensity, and Kelvin measures temperature.
#47 What is the chemical formula for ammonia?
Explanation
Ammonia has the chemical formula NH3, consisting of one nitrogen atom bonded to three hydrogen atoms. It's a colorless gas with a pungent smell, commonly used in cleaning products, fertilizers, and industrial processes. The other options represent carbon dioxide (CO2), nitrate ion (NO3-), and methane (CH4).
#48 Which of the following is the male pollen-producing reproductive part of a flower?
Explanation
The stamen is the male reproductive organ of a flower, consisting of the anther (which produces pollen) and the filament (which supports the anther). The pistil is the female reproductive part, sepals are protective leaf-like structures, and petals attract pollinators with their colors and scents.
#49 Centripetal force is an apparent force that acts outward on a body moving around a center, arising from the body's inertia.
Explanation
This statement describes centrifugal force, not centripetal force. Centripetal force is a real force that acts inward toward the center of circular motion, keeping an object moving in a curved path. Centrifugal force is the apparent outward force experienced in a rotating reference frame due to inertia.
#50 How many degrees Fahrenheit is 100 degrees Celsius?
Explanation
The conversion formula from Celsius to Fahrenheit is F = (C × 9/5) + 32. So 100°C = (100 × 9/5) + 32 = 180 + 32 = 212°F, which is the boiling point of water at sea level.