Science Leap Practice

A group of students created a circle graph that shows the distribution of water on Earth. (see image)

Which statement BEST describes the distribution of water on Earth?

• Most of Earth's water is stored in the oceans.

• Most of Earth's water is frozen in the polar ice caps.

• Most of Earth's water is flowing in streams and rivers.

• Most of Earth's water is trapped in underground aquifers.

A herring gull dies in the saltwater marsh.

Put the following steps in the correct order to model how the matter from the dead herring gull is moved in a saltwater marsh.

A. The blue crab eats the sheepshead minnow.

B. The grass shrimp eats the decaying matter.

C. The sheepshead minnow eats the grass shrimp.

D. Matter in the herring gull decays.

• A, B, C, D

• D, C, B, A

• D, B, C, A

• B, C, A, D

Nutria are non-native aquatic rodents that eat smooth cordgrass. Nutria can quickly disrupt a saltwater marsh ecosystem.

Select the organism whose population would most likely decrease FIRST if nutria were to move into the saltwater marsh ecosystem.

• blue crab

• otter

• periwinkle

• sheepshead minnow

• diamondback terrapin

Which statement best supports the answer to Question 3?

• Because the nutria eat the cordgrass, the diamondback terrapin has fewer plants to eat.

• Because the nutria eat the cordgrass, the periwinkle has less of its main food source available.

• Because the otters lose the ability to hide in the cordgrass, their predators are more likely to prey on them.

• Because the cordgrass provides less shade, the sheepshead minnows are easier for the herring gulls to see and catch.

A student reads the following information about smooth cordgrass in a science magazine.

*It is one of the few plants that grow in the tidal zone of saltwater marshes.

*It can grow to heights ranging from 6 inches to 7 feet tall.

Figure 1 shows a cross section that compares cordgrass heights in the tidal zone of a saltwater marsh. The tidal zone moves water around. This removes some of the dangerous substances that can keep plants from growing.

A student wants to know the ideal conditions for smooth cordgrass growth. Based on the information in Figure 1, which question is best for the student to investigate?

• Does cordgrass need a certain type of soil to grow taller?

• Does cordgrass need to have its seeds spread by a certain animal?

• Does cordgrass need to have a certain depth of water to grow leaves?

• Does cordgrass need a certain amount of salt in the water it grows in?

A student predicted that when the smooth cordgrass is planted in the berm, it will be ______________________ cordgrass planted in the high marsh. This is because compared to the high marsh, the berm ______________________.

• taller than, has less soil

• shorter than, has more salt in the water

• taller than, has more salt in the water

• shorter than, has less soil

Landslides

Big Sur, California, is located right next to the Pacific Ocean. The area of Big Sur has many steep cliffs and slopes. Major landslides happened there in 1998, 2000, and 2017. Landslides take place when rocks and soil move downward. Roads can be covered with rock, and parts of a road can fall into the ocean. People cannot drive through the area until soil and rocks are removed or the road is replaced. Landslides are less likely to happen on stable slopes. On stable slopes, the upper layers of rock are connected to and supported by the bottom layers of rock, as shown in Figure1. Slopes become unstable when layers of rock become separated from one another. This can happen when water fills the cracks between rocks.

A student claims that landslides are caused by the downward force of gravity. Which statements provide evidence to support the student’s claim?

Select the TWO correct answers.

• Big Sur has very steep cliffs.

• Falling rocks can cover a road.

• Rocks and soil can block traffic.

• Rock layers push against each other.

• Parts of a road may fall into the ocean.

A hiker kicks the loose rock and observes that, two minutes later, the rock has rolled to the bottom of the slope. Which statement best explains the hiker’s observations?

• Gravity pulled the rock downward only when the rock bounced over objects on the slope.

• Gravity pulled the rock straight down the entire time, which caused the rock to move downward

• Gravity pulled the rock at an angle along the ground some of the time to cause the rock to move on the slope

• Gravity pulled the rock in different directions at certain times, which caused the rock to move downward without getting stuck in the grass.

A landslide can happen when a slope becomes unstable. One way the slope can become unstable is if _______________________ cause the rocks and soil that make up the ________________________ to become loose and easy to move. Another way the slope can become unstable is if heavy rainfall or freezing ice pushes rocks and soil apart. This shows an interaction between parts of the ____________________________.

• burrowing animals in the biosphere/ geosphere/ geosphere and hydrosphere

• ocean waves in the geosphere/ biosphere/ atmosphere and geosphere

• earthquakes in the atmosphere/ hydrosphere/ biosphere and hydrosphere

• strong winds in the hydrosphere/ atmosphere/ biosphere and geosphere

Put the following statements in the correct order to model the sequence of events that causes a landslide.

A. A wildfire kills most of the plants that help make the slope stable.

B. Heavy rainfall separates the top layer of rock from the bottom layer of rock.

C. Burrowing animals create tunnels in the soil. The soil becomes loose and easy to move.

D. Wind removes loose soil from the slope. The slope becomes very steep.

• A, D, B, C

• B, D, C, A

• B, C, D, A

• A, C, D, B