Day 2 FSA Review -- Grade 8 Science

A botantist wants to determine the effect of the soil type on plant growth. He sets up three pots. Pot A has bean soil fertilizer. Pot B has tomato soil fertilizer. Pot C has turnip soil fertilizer. All three pots are given 20 mL of water each day. There are different lights on for each of the three pots. How can this experiment be further improved?

• All three pots should have the same soil

• All three pots should have the same kind of seed, the same amount of light, and the same amount of water

• The three pots should have different amounts of water

• There is nothing wrong with this experiment.

Answer explanation

Although the same amount of water was listed within the question, there were different levels of light for each pot, leading to multiple tested/independent variables. If there is multiple lights and multiple soil types, the test will not be valid. The water, light, seed, etc. should all be the same (constants) so that the quality of the soil type can appropriately be seen for plant growth.

Tags

NGSS.MS-LS1-5

NGSS.MS-LS2-1

NGSS.MS-LS2-4

Scientists have studied the melting glaciers as evidence of global warming. One team of scientists predict that the glaciers are melting at an accelerated rate. The scientists collect the same types of data on the same glaciers on the same dates each year for ten years. The scientists conclude that the glaciers have decreased in mass and increased their velocity toward the sea every successive year. Which of the following statements BEST evaluates the process that the scientists used?

• The process is a flawed experiment because the variables are not controlled.

• The process is a valid experiment because there is an independent variable and a test variable.

• The process is a flawed investigation because the investigators did not make a hypothesis

• The process is a valid investigation because scientists used systematic methods for collecting and analyzing information

Answer explanation

Remember: scientists are involved in a multitude of fields which may not always use the same systematic methods to interpret data. But every experiment should have something that the scientists are testing in order to better understand some aspect of the natural world. The process is valid because the scientists have a clear research question, background research that leads to a hypothesis, and the variables are identified.

Tags

NGSS.MS-ESS3-5

Scientific knowledge may change as new evidence or information is discovered. Which of the following would NOT be a result of new research and information?

• Binomial nonemclature is assigned to a recently identified plant species

• An endangered monkey species is put in a reserve for protection from extinction

• A newly discovered chemical element will be added to the periodic table of the elements

• A nonnative plant species will begin to reproduce rapidly after being introduced into a swamp ecosystem

Answer explanation

Three of these answers all explain systems that scientists do to better organize our understanding of the world. The nonnative plant example is something people do without care or procedure.

Two light frictionless pulleys are connected. One weight pulls on the object by 50 Newtons already. The weight of the object to be lifted is 100 Newtons. Which statement is true of the pulley system?

• Two pulleys increase the work needed to lift a 100 Newton weight

• Only an applied force greater than 100 Newtons will lift the object

• An applied force of greater than 50 Newtons will lift the weight.

• Two pulleys require more force to lift the object than a single pulley

Answer explanation

This is an FSA style question which will often have an image to help you answer this question. If you know that 50 N is already acting against the box in the system, you know that the applied force will be less than the 100 N it would be without that 50 N acting already on the pulley.

Tags

NGSS.MS-PS2-1

NGSS.MS-PS2-2

A box is pushed down by 50 N. That same box is also pushed to the left by 50 N. That same box again is pushed up by 100 N. Finally, that box is pushed to the right by 100 N. In which direction will the box accelerate?

• Up only

• Right only

• Up and right

• Up and left

Answer explanation

In a real FSA style question, you will likely have a picture which will make this answer easier to visualize. If not, draw out the forces on the box on an answer sheet. With a picture avaliable, you will be able to easily see that 100 N is going up and 50 N is going down. This means that the box will be going 50 N up. You would also be able to see that the object is going 100 N to the right and 50 N to the left. This means that the object is also going to the right.

Tags

NGSS.MS-PS2-2

Plants are considered autotrophs because they produce their own food. Which statement BEST describes how plants get their energy?

• Infrared from the soil

• Radio waves from the sun

• Ultraviolet radion from the sun

• Green light from the sun

Answer explanation

We know that plants recieve energy from the sun. We also know that green light is reflected by most plants because they are green themselves. The reason why ultraviolet radiation is the best answer is because they possess more energy and are closer in the ideal energy range for plants when compared to low energy radio waves.

Tags

NGSS.MS-LS1-6

When solar radiation crosses space and moves towards Earth, it consists of many types of radiation. Together, these radiation types are known as the electromagnetic spectrum. Which of the following properties differentiates among the different types of radiation found in the electromagnetic spectrum?

• Amplitudes

• Wavelengths

• Temperatures

• Chemical makeup

Answer explanation

While we can easily rule out temperatures and chemical makeup as nonanswers, wavelength is the best answer. Wavelength is the best answer because each wavelength is unique each type of wave in the EM Spectrum, and can be used to not only identify waves, but also mention their uses and frequencies, especially compared to each other. (Eg. Radio waves have a very long wavelength, and therefore have the smallest frequency of any other type of wave.)

Tags

NGSS.HS-PS4-1

NGSS.HS-PS4-3

NGSS.HS-PS4-4

The rock formation identified on Earth is found on the shoreline of Hudson Bay in Canada. This rock formed 4.28 billion years ago. What information does a scientist need to determine the age of a rock more accurately?

• The percentage of each mineral that makes up the rock

• The thickness of younger rock layers that cover the rock

• The amount of each radioactive element present in rock

• The amount of weathering present on the surface of the rock

Answer explanation

To get an actual age of a rock or organism, absolute dating must be used. The method most commonly used is radiometric dating, which examines the amount of each radiometric element present in the rock. (This uses radioactive carbon atoms which naturally decay into a stable carbon atom over time)

Deforestation occurs when large areas of trees are cut down. Which of the following impacts on the environment would result from deforestation?

• Increased erosion

• Colder temperatures

• Decreased ground moisture

• Greater oxygen production

Answer explanation

Tree roots hold the soil in place. When the trees are cut down, the ground is made loose and can be easily carried by agents of change like water, wind, and ice, leading to erosion.

Tags

NGSS.MS-ESS3-4

NGSS.MS-LS2-4

NGSS.MS-LS2-5

The Law of Superposition is a major principle of stratigraphy. Which of the statements below describe how the Law of Superposition helps scientists?

• Decipher the different types of sedimentary rock

• Learn more about how fossils are formed

• Learn more about how sedimentary rock is formed

• Determine the relative age of layers of rock

Answer explanation

The Law of Superposition states that the oldest layer of uninterrupted rock is that on the bottom. It also states that typically, the youngest layer is on top. Because the Law of Superposition relies on comparing multiple layers together, it is a relative dating technique, making the last option the best answer.

Tags

NGSS.MS-ESS1-4