Science Quiz

The American Heritage® Student Science Dictionaryby Editors of The American Heritage Dictionaries

The American Heritage® Student Science Dictionary Editors Have Devised A Fun and Informative Test of Science Literacy

With science literacy in the United States on the slide, the editors of The American Heritage® Student Science Dictionary have developed a science quiz to help students and their parents evaluate how science savvy they are. In sixteen short multiple-choice questions, kids and adults can test themselves — and one another.

"We hope that students, their parents, and teachers will sit down and take the quiz together," says The American Heritage® Student Science Dictionary project editor Vali Tamm. "We couldn't cover all areas of science in such a short quiz, but hope this test will motivate students and adults to improve their knowledge of science, and help them develop the skills for finding the answers they might not know."

1. Cell division involving reproductive cells is called

A. mitosisB. meiosisC. fissionD. budding

Answer: B (meiosis)

mei·o·sis ( ) A type of cell division, occurring in two phases, that reduces the number of chromosomes in reproductive cells to half the original number. It results in the

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production of reproductive cells (called gametes) in animals and the formation of spores in plants, fungi, and most algae. The first phase of meiosis involves duplication and then separation of the chromosomes, followed by division into two daughter cells that each contain half the number of chromosomes as the original cell. In the second phase, each daughter cell divides to form an additional reproductive cell. See Note at mitosis.

In early prophase, chromosomes line up to form pairs, centrioles move toward opposite ends of the cell, and the membrane surrounding the nucleus disappears. In late prophase, the chromatids line up along the center of the cell. During metaphase, each member of a chromatid pair becomes attached to spindle fibers from opposite ends of the cell. In anaphase, the chromosomes from each chromatid pair separate and begin to move toward opposite ends of the cell. During telophase, the cell divides into two new daughter cells, each with half the original number of chromosomes. In second telophase, each of the two daughter cells from the first division divides again to produce a total of four daughter cells, each having just a single set of chromosomes.

2. The protein responsible for the red color of the blood is

A. globulinB. amylaseC. histidineD. hemoglobin

Answer: D (hemoglobin)

he·mo·glo·bin ( ) An iron-containing protein in the blood of many animals that, in vertebrates, carries oxygen from the lungs to the tissues of the body and carries carbon dioxide from the tissues to the lungs. Hemoglobin is contained in the red blood cells of vertebrates and gives these cells their characteristic color. Hemoglobin is also found in many invertebrates, where it circulates freely in the blood. See Note at red blood cell.

Did You Know?

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Red Blood CellsBlood contains many cell types, but the distinctive red color comes from the aptly named red blood cells (RBCs). RBCs have their rich red color because of a vitally important iron-containing protein called hemoglobin. The protein picks up oxygen molecules as the blood exchanges gases in the lungs. The RBCs then carry oxygen to the far reaches of the body, where it is released for use by other cells, such as those of the brain and muscles. Just as importantly, after the RBC drops off its load of oxygen, its hemoglobin picks up carbon dioxide, the waste product of those brain and muscle cells, and brings it back to the lungs to be breathed out. All animals have some oxygen distribution system, but only vertebrate animals use RBCs. In some invertebrate animals, such as the earthworm, oxygen is transported using hemoglobin that is freely dissolved in the blood. Other invertebrates don't use hemoglobin at all. The horseshoe crab, for instance, uses copper instead of iron, making its blood blue instead of red.

3. Which of these structures is not made of keratin?

A. hairB. a goat's hornsC. a crab shellD. fingernails

Answer: C (a crab shell)

ker·a·tin ( ) A tough, fibrous protein that is the main structural component of hair, nails, horns, feathers, and hooves.

Did You Know?

KeratinNature ingeniously uses the same chemicals to perform a wide variety of functions in living things. An example is the group of closely related proteins known as the keratins. When nature wants something hard and tough for an animal, it turns to keratins. Your nails and hair are made mostly of a kind of keratin, and so are a dog's claws, a bird's beak, and a goat's horns. Even the hard material called baleen that some whales have in their mouths to help them eat is made of a variety of keratin. All proteins are strings of amino acids, and the keratins' secret is the amino acid known as cysteine. This amino acid tends to form strong bonds with other cysteines in the protein. The different keratins vary in hardness, depending on how many cysteine bonds are present. The bonds are what make the keratins tough as, well, nails.

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4. A typical plant cell contains all of the following except

A. a cell wallB. a large central vacuoleC. chloroplastsD. centrioles

Answer: D (centrioles)

cen·tri·ole ( ) Either of a pair of cylinder-shaped bodies found in the centrosome of an animal cell. During mitosis, the centrioles move apart to help form the spindle, which then distributes the chromosomes in the dividing cell. See more at cell, meiosis, mitosis.

CellThe cell is the basic structural unit of all organisms. From the simplest single-celled animals to the most complex multicellular ones, cells perform all of the chemical processes needed to sustain life. The cells of eukaryotes — which include most organisms except bacteria — are made up of the same basic elements: a protective cell membrane, cytoplasm, a distinct nucleas that carries much of the organism's DNA, and small bodies called organelles. Cells vary in shape and form depending on the tasks they perform.

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5. The portion of the vertebrate brain that controls voluntary movement is known as

A. the cerebrumB. the midbrainC. the thalamusD. the cerebellum

Answer: A (the cerebrum)

cer·e·brum ( ) The largest part of the vertebrate brain, filling most of the skull and consisting of two cerebral hemispheres divided by a deep groove and joined by a mass of nerve fibers. The cerebrum processes complex sensory information and controls voluntary muscle activity. In humans it is the center of thought, learning, and memory.

6. A cactus's spines are

A. woodB. leavesC. stemD. parasites

Answer: B (leaves)

cac·tus ( ) Plural cacti ( ) or cactuses. Any of various plants that have thick, leafless, often spiny stems and grow in hot, dry places, chiefly in North and South America. Photosynthesis takes place in the stems of cacti, as the leaves have evolved into narrow spines to prevent water loss. Some kinds of cacti have brightly colored flowers and edible fruit.

Did You Know?

CactusThe 2,000 species of cacti are known for living in extremely dry climates, such as the American Southwest. Cacti are excellent at conserving water. Their leaves are sharp spines, which have been known to cause great pain to animals interested in eating them. The spines also help the plant gather scarce water. Water vapor in the air condenses on the spines and then drips to the ground, where it is taken up by the roots. The roots are shallow and widely spread out to take advantage of this condensation and the rare desert rain showers. A cactus can be between 80 and 90 percent water, and its thick walls keep its water from evaporating. In fact, a cactus can be a thousand times better at conserving water than a different kind of plant of the same weight.

spine ( ) 1. See vertebral column. 2. A sharp-pointed projection on a plant, especially a hard, narrow modified leaf, as on a cactus. See more at leaf. See Notes at cactus, thorn.

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7. The difference between an object's mass and its weight is that

A. an object's mass is lighter than its weightB. an object's mass has more energy than its weightC. an object's mass is easier to accelerate than its weightD. an object's mass is independent of gravity

Answer: D (an object's mass is independent of gravity)

mass ( ) A measure of the amount of matter contained in a physical body. Mass is independent of gravity and is therefore different from weight. See Note at weight.

weight ( ) 1. The force with which an object near the Earth or another celestial body is attracted toward the center of the body by gravity. An object's weight depends on its mass (the amount of matter it consists of) and the strength of the gravitational pull. On Earth, for example, an object weighs less at the top of a very high mountain than it does at sea level, simply because the gravitational pull at the top of the mountain is lower than it is at sea level. 2. A unit used as a measure of graitational force: a table of weights and measures. 3. A system of such measures: avoirdupois weight; troy weight.

Weight/MassIt's easy to convert pounds into kilograms: just multiply the number of pounds by .45 (or if you want greater precision, use .4536). But no matter how many times you do this conversion, you will always be making a mistake, because a pound is a unit of force, while a kilogram is a unit of mass. A pound is a measure of the force that a gravitational field exerts on an object. As such, a pound is a unit of weight, not of mass. An object's mass is its ability to resist changes in the speed or direction of its motion, and it is always the same regardless of what forces are acting upon it. If you were walking on the moon, for example, your mass would be the same as it is on the Earth, but your weight would be one sixth of what it is on the Earth because of the lower gravitational pull of the moon. If this is so, you might ask, how can my science teacher ask me to convert pounds into kilograms? When we make such conversions, we are assuming that the object in question is on the Earth, at sea level, where the conversion factor works for all practical purposes.

8. A pit viper is so called because

A. it loves to sleep in pitsB. it has a hollow beneath its chin, where it conceals its fangsC. it has a heat-sensing hole beneath each eyeD. it eats the pits of fruit

Answer: C (it has a heat-sensing hole beneath each eye)

pit viper Any of various venomous snakes having a small pit below each eye that is used to

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sense heat. Their fangs are hollow and folded back in the mouth when the snake is not striking prey. Pit vipers are mostly found in the Western Hemisphere and include the cottonmouth and rattlesnakes.

9. If you had an ovipositor you would be

A. a female insectB. a male insectC. an electric eelD. a sheep

Answer: A (a female insect)

o·vi·pos·i·tor ( ) A tube in many female insects that extends from the end of the abdomen and is used to lay eggs.

10. The discoverer of the principle of buoyancy was

A. Sir Francis CrickB. Sir Francis ChichesterC. Sir Francis BaconD. Archimedes

Answer: D (Archimedes)

Ar·chi·me·des ( ) 287? – 212 B.C. Greek mathematician, engineer, and inventor. He made numerous mathematical discoveries, including the ratio of the radius of a circle to its circumference as well as formulas for the areas and volumes of various geometric figures. Archimedes created the science of mechanics, devising the first general theory of levers and finding methods for determining the center of gravity of a variety of bodies.

ArchimedesArchimedes would still be famous today even without the legend that he ran through the streets of his home in Sicily naked. One of his most important discoveries was that of buoyancy: an object placed in water displaces a volume of water equal to its own volume. The story goes that the king of Archimedes's hometown of Syracuse wanted Archimedes to test a golden crown to make sure it was made of pure gold (and not gold mixed with silver). According to the story, Archimedes puzzled over the problem until one day when he was taking a bath he saw how his body made the water overflow, and in a flash of insight discovered the principle of displacement. He dashed through the neighborhood yelling "Eureka!" (Greek for "I've found it!"), forgetting to dress first. He knew that gold was heavier than silver and now realized that a given weight of gold would have less volume—and therefore displace less water—than an equal weight of silver. He determined the volume of the crown from the volume of water it displaced, weighed the crown, and found that indeed it was too light to be made of pure gold.

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11. What do bacteria lack that almost all other cells have?

A. an electric currentB. a cell nucleusC. DNAD. amino acids

Answer: B (a cell nucleus)

bacterium ( ) Plural bacteria. Any of a large group of one-celled organisms that lack a cell nucleus, reproduce by fission or by forming spores, and in some cases cause disease. They are found in all living things and in all of the Earth's environments, and usually live off other organisms. Bacteria make up most of the kingdom of prokaryotes. — Adjective bacterial.

Bacterium/bacteriaIt is important to remember that bacteria is the plural of bacterium, and that saying a bacteria is incorrect. It is correct to say The soil sample contains millions of bacteria, and Tetanus is caused by a bacterium.

12. Which of the following is not true about quasars?

A. they are among the most distant celestial objects known, and some are more than ten billion light-years away

B. many astronomers believe that the source of a quasar's energy is a huge black hole rotating at the center of a young galaxy

C. the light they emit appears blue because of the Doppler effect, showing that the universe is contracting

D. one of these objects can be a trillion times brighter than the sun

Answer: C (the light they emit appears blue because of the Doppler effect, showing that the universe is contracting)

qua·sar ( ) An extremely distant, compact, star-like celestial object. The power output of a quasar is several thousand times that of the Milky Way galaxy.

Did You Know?

Quasar

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"The universe is not only stranger than we imagine," Albert Einstein said. "It is stranger than we can imagine." In the 1960s, astronomers found some very strange objects that we now call quasars in the far reaches of the universe. A quasar is like a far-off floodlight. It appears to be an extremely distant star putting out huge amounts of energy. In fact, just one of these objects can be a trillion times brighter than the sun. All of the radiation that a quasar gives off comes from a small area at its center, and many astronomers believe that the source of the energy is an enormous black hole rotating at the center of a young galaxy. Quasars are among the most distant celestial objects known. Some are more than ten billion light-years away, meaning their radiation has taken ten billion years to reach us. So when we look at quasars, we're observing these objects as they were billions of years ago, and we're able to see part of the early history of the universe.

13. What causes a black hole to form?

A. a star the size of the sun consumes all the fuel in its core and burns outB. the fabric of space-time rips, opening a portal to another dimensionC. two stars collide in a giant explosion known as a supernovaD. a large star's core collapses to become so dense that its gravitational pull keeps light from

escaping

Answer: D (a large star's core collapses to become so dense that its gravitational pull keeps light from escaping)

black hole An extremely dense celestial object that has a gravitational field so strong that nothing can escape, not even light. A black hole is formed by the collapse of a massive star's core in a supernova. See more at star.

Did You Know?

Black HoleOne of the strangest objects in the universe is the burnt-out remnant of a large star, known as a black hole. The name comes from the fact that the star collapses into itself, becoming so dense that its gravitational pull keeps even light from escaping. And if light can't get out, then nothing that ever enters the black hole would ever escape. Rockets to the moon or Mars need to achieve what is called escape velocity, the speed necessary to overcome the Earth's gravity. But since nothing can ever go faster than the speed of light, nothing could ever go fast enough to reach the escape velocity necessary to pull out of a black hole. Here's how dense a black hole is: the sun has a diameter of about 864,000 miles (1,390,000 kilometers); for it to be as dense as a black hole, its entire mass would have to be squeezed down to a ball less than two miles across.

Star

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A star is a giant sphere of gas that produces its own light by making its own energy. It generates this energy through nuclear fusion in its core, using as fuel the elements that make it up. Fusion in a star combines atoms of lighter elements, such as hydrogen, into different, heavier elements, such as helium. A massive star can burn its fuel into elements as heavy as iron. Nuclear fusion begins when a star is fully formed out of a nebula and ends when a smaller star burns out and becomes a white dwarf or when a massive star's iron core collapses in a supernova. Because a star's composition changes as it burns its fuel, it goes through a series of stages during the course of its life, hundreds of milions or billions of years long.

14. Which of the following is NOT measured in degrees?

A. the latitude or longitude of the Earth's surfaceB. the depth of water in the oceanC. temperatureD. an angle or an arc of a circle

Answer: B (the depth of water in the ocean)

de·gree ( ) 1. A unit division of a temperature scale. See Note at Celsius. 2a. A unit for measuring an angle or an arc of a circle. One degree is 1/360 of a circumference of a circle. b. This unit used to measure latitude or longitude on the Earth's surface. 3. In a polynomial, the degree of the term that has the highest degree. For example, x3 + 2xy + x is of the third degree.

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15. The basic unit of mass in the metric system is the

A. wattB. meterC. literD. kilogram

Answer: D (Kilogram)

kil·o·gram ( ) The basic unit of mass in the metric system, equal to 1,000 grams (2.2 pounds). See Table at measurement. See Note at weight.

metric system A decimal system of weights and measures based on the meter as a unit of length, the kilogram as a unit of mass, and the liter as a unit of volume. See Table at measurement.

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16. How did Galen come up with his theories about the structure and functions of the human body?

A. by dissecting the human bodyB. by dissecting animalsC. he read a lot of encyclopedias about itD. they came to him in a dream

Answer: B (by dissecting animals)

Ga·len ( ) A.D. 130?-200? Greek anatomist, physician, and writer. He developed numerous theories about the structures and functions of the human body, many of which were based on information he gained from dissecting animals. Galen's theories formed the basis of European medicine until the Renaissance.

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