1. What happens if new evidence is discovered about atoms that current theories about atoms do no explain?

Transcription

1 Grade 7 Science Pretest 1. What happens if new evidence is discovered about atoms that current theories about atoms do no explain? a. Nothing, current theories about atoms are hypotheses and don t need to be supported by new evidence. b. Nothing, current theories about atoms are scientists best ideas, so those theories remain valid. c. Current theories about atoms will be modified considering the new evidence. d. Current theories about atoms will be abandoned for a new theory. 2. Which of the following physical states has particles that vibrate in place and do not move past their neighbors? a. gas b. liquid c. molecule d. solid 3. In 1808, Dalton proposed that matter is made of atoms. About 80 years later, Thompson created the plum pudding model of the atom, which was later abandoned. Around 1900, Rutherford performed an experiment that gave evidence that atoms have a nucleus. Later, Bohr proposed a model that explains how electrons may orbit the nucleus. What does this information show about current knowledge of atoms? a. Scientists have built upon previous knowledge and ideas about atoms. b. Scientists each have their own ideas about atoms that are unrelated to previous information. c. Scientists can only contribute scientific knowledge if they get the model of the atom completely right. d. It takes more than 100 years to make major discoveries in science. 4. The formula for density is density = mass/volume (D=M/V). What is the density of a rock with a volume of 5 cubic centimeters and a mass of 3 grams? a g/cm³ b g/cm³ c. 15 cm/g³ d cm/g³ 5. You have two rocks, rock A and rock B. Rock A is bigger but has the same mass as rock B. How will the density of the two rocks compare? a. The density of rock B is greater because its volume is greater. b. The density of rock B is greater because its volume is less. c. The density of rock B is less because its volume is greater. d. The density of rock B is less because its volume is less.

2 6. What is the volume of the rock in the pictures below? a. 4mL b. 10 ml c. G g d. 12 g 7. Why would a bridge builder construct a large steel bride with 1-inch cracks or spaces every 50 feet along the roadway of the bridge? a. To save steel and paving material. b. So that when the wind blows the bridge will not crack. c. So that in the winter as the ice melts it can easily drain off the bridges surface. d. To allow for the expansion and contraction of the structure of the bridge.

3 8. Students conducted an experiment testing the time it takes food coloring to mix with water. The results of the experiment are summarized in the table below. Which sentence best explains the results? Beaker Temperature in Celsius Time until mixed A 3 degrees 3 minutes 45 seconds B 20 degrees 2 minutes 10 seconds C 90 degrees 1 minute 15 seconds a. The coloring mixed faster in A because the molecules in cold water move faster. b. The coloring mixed faster in C because the molecules in hot water move faster. c. The coloring mixed slower in A because the molecules in cold water move faster. d. The coloring mixed slower in C because the molecules in cold water move slower. 9. Two students performed investigations to explore the hypothesis that particles of matter are continually in motion. The students experiments are as follows: (1) Student one opened a bottle of perfume in a classroom and the aroma could soon be smelled in distant parts of the classroom. (2) Student two shined a flashlight in a dark classroom and noticed many particles moving through the beam of light. Which sentence best describes the investigations, conclusions and methods? a. Neither experiment provided evidence to support the hypothesis that particles continually move. b. Both experiments provided evidence to support the hypothesis that particles continually move. c. Both experiments provided evidence that particles are not constantly moving. d. Experiment (1) provided evidence to support the hypothesis, while experiment (2) did not. 10. Melinda works at a water treatment plant. She wants to find out whether particle size affects the way particles settle in water. Can Melinda use scientific methods to answer her question? a. No, it is not possible to know why particles settle in water the way they do. b. No, only scientists can use real scientific methods. c. Yes, whenever someone asks a question they are doing science. d. Yes, science is a way of knowing used by non-scientists. 11. Use the data in the table below to answer the following question. When mixed, shaken and left to settle, what would be the order of the substances starting from the bottom and going up? Substance Oil Water Plastic Aluminum Rock Density 0.8 g/ml 1.0 g/ml 0.9 g/ml 2.7 g/ml 4.2 g/ml a. rock, aluminum, plastic, water, oil b. rock, aluminum, water, plastic, oil c. rock, plastic, oil, water, aluminum d. rock, oil, aluminum, plastic, water

4 12. An egg sinks in pure water but floats in salt water. What do you know about the density of the egg? a. It is more dense than pure water but less dense than salt water. b. It is less dense than pure water and less dense that salt water. c. It is more dense than pure water and more dense than salt water. d. It is less dense than pure water but more dense that salt water. 13. You are given the following materials and their densities and then asked to construct a model of the earth consisting of a core, mantle, crust and air. Based on density, which material would be the best choice to represent the Crust of the Earth? Cotton Glue Clay Aluminum foil A nickel 0.2 g/ml 1.0 g/ml 1.8 g/ml 2.7 g/ml 4.6 g/ml a. cotton b. clay c. aluminum foil d. nickel 14. Which of the following statements best explains why Earth is layered in the following order? air water crust core a. Things on Earth are ordered by color, red on the bottom and blue on the top. b. Things on Earth are ordered by density, most dense on the bottom. c. Things on Earth are ordered by particle size, largest particles on the bottom d. Things on Earth are ordered by temperature, hottest on the bottom. 15. The development of the seismograph allows scientists to determine how fast waves travel through the core of the Earth. From this, they can infer densities and states of matter of the materials inside the Earth. How has this technology influenced current models of Earth s structure a. It provides evidence that the core is made of liquid and solid layers. b. It shows that the crust is solid and more dense than the mantle. c. It proves that the mantle moves with convection currents. d. It gives information about temperatures and pressures at the bottom of the sea. 16. If a cell that is 80% water is placed in a solution that is 40% water, which way will the net movement of water go? a. out of the cell b. neither way c. into the cell

5 17. How has technology influenced our ability to study cells? a. Satellites allow scientists to test the chemicals in plant cells. b. Electron microscopes allow us to see detailed pictures of cells. c. High-resolution amplifiers help scientists study cell parts. d. Telescopes allow scientists to look for cells on other planets. 18. Study the diagram of the two cells below. Which is a plant cell, A or B? a. Cell A because plant cells are not round and have a bigger nucleus. b. Cell A because plant cells have a cell wall that helps hold their shape. c. Cell B because the oblong structures in cell B look like chloroplasts. d. Neither is a plant cell. Plant cells do not have that maze-looking structure. 19. Which statement best describes the future of our knowledge about the heart? a. Knowledge will probably change because scientists like to change things. b. Knowledge will change because discoveries will provide new information about the heart. c. Knowledge will probably stay the same. Scientists have learned all there is to know about the heart. d. Knowledge will probably stay the same. Scientists are more interested in other parts of the body. 20. Which list correctly states the 5 levels of organization from simplest to the most complex? a. person, muscle cell, heart, circulatory system, cardiac muscle b. person, circulatory system, heart, cardiac muscle, muscle cell c. muscle cell, heart, cardiac muscle, circulatory system, person d. muscle cell, cardiac muscle, heart, circulatory system, person 21. Which of the following is an example of an organ? a. large intestine b. inner lining of the stomach c. digestive system d. muscle fiber

6 22. Which statement correctly gives a difference about the exchange of genetic material in sexual and asexual reproduction? a. Genetic material comes from two parents in sexual reproduction and just one parent in asexual reproduction. b. Variation in genetic material is more likely in asexual preproduction than in sexual reproduction. c. For both types of reproduction, the amount of genetic material in the offspring is the same as in each parent. d. Cells that are involved in both types of reproduction are identical to begin with. 23. Look at the data table. Which of the graphs best displays the data? a. b. # of individuals Asexual reproduction Number of individuals Parent 1 1 st generation of offspring 2 2 nd generation of offspring 4 3 rd generation of offspring 8 4 th generation of offspring 16 5 th generation of offspring 32 6 th generation of offspring 64 # of individuals c. # of individuals d. # of individuals

7 24. A farmer planted the same variety of corn in two different fields, one in a field he had used before and one in a field that was new. The corn in the new field grew larger kernels than the corn in the old field. The farmer concluded that he should eat the corn from the new field and save the corn from the old field for seed. Was the farmer s conclusion a good one? a. Yes, anyone can form good conclusions based on data and the corn from the old field can grow large kernels as well as the corn from the new field. b. No, the farmer is not a scientist and should not form conclusions. Also, the corn from the new field will grow larger kernels when it is planted next year. c. No, the farmer is not a scientist and should not form conclusions even though the corn from the old field can grow large kernels as well as the corn from the new field. d. No, although anyone can form good conclusions based on data, the corn from the new field will grow larger kernels when it is planted next year. 25. Birds in desert climate survive on soft parts of cactus. Scientists observed that during a drought, many of the birds died. The ones that survived had larger beaks and were able to crack open and eat hard seeds that would ordinarily not be used. The next generation of birds all had large beaks. How did inherited traits help some birds survive? a. All surviving birds migrate. b. Inherited traits helped birds get water. c. Inherited traits helped birds eat different food. d. The inherited traits changed the environment. 26. Which is the best example of how science and improvements in technology affect life? a. A birdwatcher feed seeds to birds in the winter. b. A person plants a garden in her backyard to grow vegetables. c. A student watches a garter snake eat a mouse. d. A dairy farmer chooses cows that produce more milk. 27. The more classification levels shared by two organisms. a. the easier it is to tell two organisms apart. b. the more distantly related the two organisms are. c. the more characteristics they have in common. d. the closer they live together in their environment. 28. Why is a frog considered a living organism and a computer is NOT? a. A frog can reproduce and a computer cannot. b. A computer is shaped like a cube and living things are not. c. A frog can move and a computer cannot. d. A computer uses energy and living things do not.

8 29. Which group contains ONLY living or once-living matter? a. hair, glass, steel, ink b. hair, wood, bold, leaf c. paper, sand, salt, wool d. steel, salt, rubber, rock 30. Why is the ability to observe carefully important when describing and classifying new species? a. Because most living things are easy to see. b. Because classifying organisms is based mainly on structure. c. Because looking at things and studying them is the most enjoyable thing to do in science. d. Because organisms are classified based mainly on where they live. 31. Which of the following characteristics would best be used to develop a classification key for birds? a. The person who first discovered the bird. b. How plentiful that bird is in your neighborhood. c. What food the bird eats. d. Color markings on the bird s head. 32. Which of the following is true when an organism has the same scientific name as another organism? a. This does not happen in classifications. b. They share one or two common traits. c. They are the same identical species. d. Someone made a mistake naming them. 33. The ability to classify and name organisms has allowed scientists to communicate their findings with each other and study each other s work. Listed below are some developments that have led to our current knowledge about organisms. 1. Invention of the microscope. 2. Aristotle classified all organisms as plants or animals. 3. A 5-kingdom classification system was developed. 4. DNA used to identify relationships between species. a. 2,1,3,4 b. 1,2,3,4 c. 1,2,4,3 d. 2,3,1,4

9 34. What do scientists do when a new type of organism is discovered that does not fit into current classification systems? a. Nothing, there are many organisms that do not fit into current classification systems. b. Nothing, they wait until they find at least 10 new species and then make a new place in the classification system. c. Scientists create a new classification system and discard old classification systems. d. Scientists modify current classification systems to make a place for the new organism. 35. Study the picture and the key below. What is this plant? Conifer Dichotomous Key 1a. Leaves are scale-like, growing along the branch. Cones are berry-like Juniper b. Leaves are needle-like, growing out from the branch. Go to 2 2a. Leaves come out from the branch singly.. Go to 3 b. Leaves come in packets of 2 or more; cones are woody. Pine 3a. Leaves are sharp on the end and square in cross-section.. Spruce b. Leaves are round on the end Fir a. Juniper because the leaves are scale-like and grow along the branch. b. Juniper because the needle-like leaves come in packets of 2 or more. c. Fir because the leaves are sharp on the end and come out of the branch singly. d. Fir because the ends of the leaves are round and come out of the branch singly. 36. Many people have the misconception that mushrooms belong to the Plant Kingdom. To learn about mushrooms you conduct an experiment by growing plants and mushrooms under different amounts of light. You obtain the following data from your experiment. Based upon this data, which of the following is the best conclusion? Organism Amount of water per day Hours of light per day Growth/description after 2 weeks Mushroom #1 100 ml 8 4 inches - healthy Mushroom #2 100 ml 0 4 inches - healthy Plant #1 100 ml 8 4 inches - healthy Plant #2 100 ml 0 0 inches - dead a. Mushrooms belong to the Plant Kingdom because they can grow in 8 hours of light. b. Mushrooms belong to the Plant Kingdom because they need lots of water each day. c. Mushrooms do NOT belong to the Plant Kingdom because they can grow in the dark. d. Mushrooms do NOT belong to the Plant Kingdom because they need lots of water.