SCIENCE 7 REVIEWER

A drug selectively prevents formation of the large ribosomal subunit. Which cellular process would be most directly impaired?. DNA replication. Phospholipid diffusion. Osmosis. Translation of mRNA. Glycolysis.

Shortest straight-line change in position (with direction). Motion. Distance. Displacement. Velocity. Acceleration.

Rate of change of velocity. Motion. Distance. Displacement. Velocity. Acceleration.

Speed with direction. Motion. Distance. Displacement. Velocity. Acceleration.

Total path traveled. Motion. Distance. Displacement. Velocity. Acceleration.

Distance travelled over time. Motion. Speed. Displacement. Velocity. Acceleration.

Amount of matter in an object. Force. Mass. Weight. Volume. Gravity.

Force of gravity acting on an object. Force. Mass. Weight. Volume. Gravity.

A push or pull acting on an object. Force. Mass. Weight. Momentum. Gravity.

Done when a force moves an object over a distance. Force. Work. Energy. Momentum. Mass.

Energy cannot be created or destroyed, only transformed. Newton’s law of universal gravitation. Law of Conservation of Energy. Law of Conservation of Mass. Newton’s First law of motion (Inertia). Law of Conservation of Momentum.

Heat transfer through direct contact. Radiation. Conduction. Convection. Evaporation. Insulation.

Given block B is 200 g and block C is 1000 g , in order to balance the lever system as shown in the following figure, which of the following should block A be?. 400 g. 500 g. 600 g. 700 g. 800 g.

Which of the following is an example of endothermic process?. Compression of gas. Iron rusting. Neutralization between acid and base. Sugar dissolved in lemon tea. Water frozen as Ice.

Which of the following best describes energy changes of a meteorite when it crashes into Earth?. Chemical Energy > Heat Energy > Kinetic Energy. Gravitational Potential Energy > Heat Energy. Gravitational Potential Energy > Kinetic Energy > Heat Energy. Heat Energy > Kinetic Energy > Chemical Energy. Kinetic Energy > Gravitational Potential Energy > Heat Energy.

Secondary rainbow are the faint rainbow that appear just outside the primary rainbow, the primary and the secondary rainbow are formed as concentric arcs. Which of the following is the cause of this phenomenon?. Second Reflection inside the rain droplet. Second Refraction inside the rain droplet. Interference of light waves emerging from the rain droplet. Reflection from impurities inside the rain droplet. Refraction through impurities inside the rain droplet.

Hurricanes in the northern hemisphere always spin counterclockwise, and hurricanes in the southern hemisphere always spin clockwise. Which of the following is the cause of this phenomenon?. Earth’s revolution around the Sun. Earth’s rotation around its own axis. Moon’s revolution around Earth. Moon’s rotation around its own axis. Sun’s rotation around its own axis.

Which of the following is the primary use of electric fuse?. Amplify the current passing through. Ensure the current travels in one direction only. Prevent short circuits or mismatched loads. Provide a path for a fault current to flow to earth. Receive sign from the remote control.

Which of the following statements is not correct about light?. Light is a form of energy. Light can be reflected. Light can be bent. Light travels with the same speed in all medium. None of the above.

Which combination of statements is correct? i. A simple electric circuit can be prepared by using an electric cell, a bulb, a switch and connecting wires. ii. In the symbol of the electric cell, the longer line represents the positive terminal and the thicker, shorter line represents the negative terminal. iii. When electric current passes through a wire, it behaves like a magnet. iv. Electric current can be used to make magnets. v. When filament of an electric current is broken, the bulb is said to be fused. i and iii only. i, ii, and iv only. i, iv, and v only. all i, ii, iii, iv, and v. None of the above.

Which combination of statements is correct? i. A mirror changes the direction of light that falls on it. This is called refraction of light. ii. Any polished or a shining surface acts as a mirror. iii. All types of images can be obtained on a screen. iv. Image formed by a convex mirror is erect, virtual and smaller in size than the object. v. A concave lens always forms erect, virtual and smaller image than the object. i and iii only. i, ii, and iv only. ii, iv, and v only. i, iv, and v only. All of the above.

A student observes that bean plants growing near a classroom window appear taller than bean plants growing farther inside the room. The student wants to investigate the observation scientifically. Which question is most directly investigable?. Why do plants prefer growing near windows?. Does the amount of light received affect the average height of bean plants over 21 days?. Are plants near windows healthier than all other plants?. Which location is the best place for every type of plant to grow?. Why is sunlight important for the survival of living organisms?.

An investigation tests how dissolved salt concentrations (0%, 1%, 3%, and 5%) affect the heart rate of a transparent water flea (Daphnia magna). The experimenter runs three trials for each concentration using a new flea each time, while keeping temperature, light, and water volume constant. What is the independent variable in this experiment?. The average heart rate of the water flea in beats per minute. The water temperature and room light intensity. The concentration of dissolved salt added to the water. The total volume of liquid placed on the microscope slide. The total observation time spent under the microscope light.

A student records the observation: “The plant looked healthier after the fertilizer treatment.” What is the strongest criticism of this statement as a scientific observation?. The observation does not identify which plant characteristics changed after the treatment. The observation is invalid because plant health cannot be studied through observation. The observation is inappropriate because fertilizer treatments must always produce visible changes. The observation cannot be used because scientific observations must be based only on numerical data. The observation is reliable as long as the student personally judged the plants to be healthy.

A drug selectively prevents formation of the large ribosomal subunit. Which cellular process would be most directly impaired?. DNA replication. Phospholipid diffusion. Osmosis. Translation of mRNA. Glycolysis.

A cell is placed in a solution with a lower effective solute concentration than the cell's cytoplasm. The membrane allows water to cross but restricts the major solutes. What is the expected net movement of water?. Water will move into the cell because the external solution is hypotonic. Water will move out of the cell because the external solution is more dilute. Water will move equally in both directions with no net movement. Water movement will depend primarily on the concentration of glucose outside the cell. Water will remain outside because solutes cannot cross the membrane.

A mutation replaces a charged amino acid in an enzyme's active site with a nonpolar amino acid. What is the most likely effect on the enzyme?. Substrate binding or catalysis may change because the active site's chemical environment is altered. The enzyme may become more stable because nonpolar residues always strengthen protein structure. The reaction may become independent of substrate concentration. The enzyme's activation energy will necessarily increase to zero. The enzyme will retain exactly the same activity because only the amino-acid sequence has changed.

Which modification most directly improves the reliability of a biological experiment?. Increasing replication. Changing several variables simultaneously. Removing the control. Reporting more decimal places. Choosing only favorable results.