LEAP 2025 Session 2 Review

LEAP 2025 Session 2 Review

By Tyler Ussery

Banded Snails

Banded snails, found in Central Europe, are small- to medium-sized snails that are members of the Helicidae family. Their shells are found in a range of colors and patterns, from yellow to dark brown and from no bands (or stripes) to five bands. Image 1 shows an example of a banded snail with five bands. Banded snails are prey to several bird species, including the song thrush. The color and pattern of the bands are based on genetics and heredity, and follow the Mendelian rules of inheritance. In addition, snails with lighter-colored shells have a lower body temperature than those with darker-colored shells. In some areas, snails with many different colors and band patterns are found. In other areas, certain shell colors or patterns are more common. Graph 1 shows the percentages of snails with different shell colors and band patterns found in different habitats.

Climate can play a significant role in the survival advantages of each color and banding pattern. Snails with darker-colored shells tend to be found living farther north than those with lighter-colored shells. Scientists have observed that the climate in Central Europe is changing faster than in other areas. This impacts not only the local organisms, but migratory species of birds and animals as well. Graph 2 shows how the average winter and summer temperature deviations in Central Europe have changed over time.

The effect of climate on the population of yellow-banded snails is shown in Figure 1.

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Use the information about banded snails and your knowledge of science to answer the questions.

Multiple Choice

Which claim is supported by evidence from Graph 1?

• Snails with yellow shells live in all three habitats, but those with banding have a survival advantage in hedge

  habitats.

• Snails with yellow shells and banding are less able to survive in wood habitats.

• Snails with brown shells live in all three habitats, but they have a survival advantage in meadow habitats.

• Snails with brown shells and no banding are most often found in meadow habitats.

Multiple Choice

Use Graph 2 and Figure 1 to answer the question.

Part A

Which statement best predicts how yellow-banded snails will be affected if the trends shown in Graph 2 continue?

• Yellow-banded snails will migrate from higher elevations to lower elevations.

• Yellow-banded snails will migrate from northern regions to southern regions.

• Yellow-banded snails will become more common in areas that have historically cooler temperatures.

• Yellow-banded snails will be found in a much wider range than the region in which they were historically

  found.

Multiple Choice

Part B

Which statement supports your prediction from Part A?

• Yellow-banded snails are able to live in all environments, but predation rates were historically higher in certain

  areas prior to climate change.

• Yellow-banded snails in cooler areas will become extinct because they are unable to adapt to changing

  conditions.

• Yellow-banded snails will move to areas where there are fewer migratory predators.

• Yellow-banded snails are better suited to live in warmer climates than snails with other-colored shells.

Multiple Select

As the climate in northern regions changes, the population of snails with darker-colored shells will likely (A)___________ because

they have (B)______________ than snails with lighter-colored shells.

• (A)increase

• (A)decrease

• (B)better camouflage

• (B)higher body temperatures

• (B)lower rates of predation

Draw

Match the following Effects to the correct Cause by drawing the letter in the corresponding box

(A) Only snails with a lighter shell color and banding are able to

survive in the new environment.

(B) Dark-colored banded snails become more common than

yellow-colored banded snails.

(C)Snails of any color with the most banding survive better than

snails with any color and no banding.

(D)Snails with a darker shell color are less likely to survive and

reproduce to pass traits on to offspring.

Open Ended

As you respond to Part A, Part B, and Part C, follow the directions below.

Address all of the instructions in each prompt.

Use the evidence from the information provided and your own knowledge of science to support your responses.

Part A

Based on the information in Graph 1, explain the relationships between shell color, presence of banding, and habitat. Use the evidence

from the graph to support your answer.

Open Ended

Part B

The characteristics of two snail populations are shown.

Population 1: high degree of genetic variation among snails living in a wood environment at higher elevations

Population 2: all snails have the same traits specialized for a hedge environment that is found in warmer locations

Explain how each snail population will likely be affected if the trend shown in Graph 2 continues. Use evidence from Graph 1 and Graph 2,

to support your explanation.

Open Ended

Part C

Describe the snail color that will offer the greatest selective advantage if the trends shown in Graph 2 continue. Use evidence from the

information on banded snails to support your claim.

Multiple Select

Use the information and your knowledge of science to answer the question.

Like all fruit, pears continue to undergo cellular respiration after they are harvested. As pears ripen, they begin respiration, and carbohydrates in the fruit are converted to other forms. If enough time goes by, the fruit may begin to rot. Growers want to keep the pears unripe for as long as possible, and ripen the fruit just before sending them to the supermarket. For this reason, growers have investigated storing pears under different conditions. The graph shows the results of one investigation.

Select the correct answers to complete the sentences related to cellular respiration in pears.

For long-term storage of pears, the oxygen concentration should be_______ and the temperature should be _______. This will result in the least amount of energy being used by the pears.

• 7 Degrees Celsius

• 15 Degrees Celsius

• 5% O2

• 10% O2

• 23% O2

Multiple Choice

A scientist crosses morning glory plants of different flower colors to determine how flower color is passed on to offspring. The results of three crosses are shown in the table.

The scientist crosses an offspring from cross X with an offspring from cross Z. What are the expected results of this

cross?

• 100% of plants with red flowers

• 100% of plants with purple flowers

• 50% of plants with red flowers, 50% of plants with purple flowers

• 75% of plants with purple flowers, 25% of plants with red flowers

Multiple Select

Which statements describe steps in photosynthesis?

Select the three correct answers.

• Glucose is broken down into carbon dioxide and water.

• Light energy is absorbed by chlorophyll.

• Organic matter and oxygen combine to break molecules into smaller parts.

• Energy is used to convert carbon dioxide and water into sugar.

• Water is broken apart to produce oxygen.