Ecology CSA corrections

Since the early 2000s, sea-star-wasting disease has affected the purple sea star population along the West Coast of the United States. In the 1960s, ecologists did an experiment, temporarily removing purple sea stars from a tide pool. During the experiment, the ecologists continually removed the sea stars from the tide pool for two years until their population was removed completely. Figure 1 shows the major organisms in the tide pool food web before the experiment, after one year, and after five years. What was the main organism present five years after the sea star removal?

• Gooseck barnacle

• Anemone

• Mussel

• Sea Snail

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-3

NGSS.MS-LS2-4

Since the early 2000s, sea-star-wasting disease has affected the purple sea star population along the West Coast of the United States. In the 1960s, ecologists did an experiment temporarily removing purple sea stars from a tide pool. During the experiment, the ecologists continually removed the sea stars from the tide pool for two years until their population was removed completely. Figure 1 shows the major organisms in the tide pool food web before the experiment, after one year, and after five years. Ecologists claim that sea-star-wasting disease will severely disrupt the coastal ecosystem. This claim is supported because:

• A) Species richness increased during the experiment.

• B) The coast is a much larger area than a tide pool with many more species.

• C) The ecosystem remained stable after the sea stars were removed in the experiment.

• D) The biodiversity remained low long after the sea stars were removed in the experiment.

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-4

(LS2.1) Scientists placed the bacteria P. fluorescens on a bean leaf and measured the total amount of sugar and bacteria population on the leaf. The leaf produces sugar continuously. Over time, the bacterial population changed. Figure 1 shows the amount of total sugar over time. Time is measured in hours (hr) and total sugar is measured in micrograms (μg) on one gram of leaf. Table 1 shows the population of bacteria over time. The population is measured in the number of viable cells on one gram of leaf. Viable bacterial cells are able to multiply. Calculate the slope (y2-y1/x2-x1) for the change in bacteria population overtime from 0 to 18 hours. Enter the numbers in the blank boxes. Round your answer to the nearest hundredths (0.00). 0-18 hours: __________ x 10⁷ cells/hr

• 0.02

• 0.05

• 0.08

• 0.10

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-4

Calculate the slope (y2-y1/x2-x1) for the change in bacteria population overtime from 18 to 25 hours. Enter the numbers in the blank boxes. Round your answer to the nearest hundredths (0.00). 18-25 hours: __________ x 10⁷ cells/hr

• 0.18
• 0.02

• 1.2

• -0.18

Tags

NGSS.MS-LS2-1

The number of bandicoots found on the Western Peninsula of Australia is different from the number of bandicoots found on Dorre Island, off the coast of Australia. Bandicoots are small mammals that are native to Australia. What is the best explanation for why the population is smaller on the Western Peninsula?

• The predators on the western peninsula keeps population numbers down compared to Dorre Island

• Dorre Island has less bandicoots due to a smaller area and absence of predators.

• Both regions have the same number of bandicoots.

• The Western Peninsula has fewer bandicoots due to a smaller area and absence of predators.

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-4

What is the population trend of the Dorre Island bandicoots after 2007?

• The population on Dorre Island increased.

• The population on Dorre Island continued to decline.

• The population on the Western Peninsula began to recover.

• The population on the Western Peninsula continued to decline.

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-4

What is the main difference in the limiting factors that affect the bandicoot population on the Western Peninsula and Dorre Island?

• The Western Peninsula has more predators.

• Dorre Island has a larger area.

• The Western Peninsula has a higher annual precipitation.

• Dorre Island has more predators

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-4

In the early 1930s, beetles were destroying sugar cane fields in Australia. In 1935, farmers introduced cane toads from Puerto Rico to control the beetles. They bred over 100 toads in captivity before releasing them into the wild. Table 1 gives information about the number of cane toads in 1935. Using the data presented, which statement about the cane toad population in Australia is true?

• The cane toad population exhibits logistic growth and has reached its carrying capacity.

• The cane toad population exhibits linear growth and will never reach its carrying capacity.

• The cane toad population exhibits is in the linear phase of logistic growth before approaching it carrying capacity.

• The cane toad population exhibits exponential growth and the population may exceed its carrying capacity.

Tags

NGSS.MS-LS2-3

NGSS.MS-LS2-4

(LS2.4) After a sharp decline in the wolf population on an island in Lake Superior, the biomass of forage changed. The total area of the island is 534 square kilometers (km2). The Average mass of a moose is 367kg.

Determine the mass of the moose population on the island in 1980. Moose Density 1980: 1.4

Mass Equation= (Moose Density x Moose Average Mass x total area of the island)

• 274369

• 300000

• 230444

• 345677

Estimate the mass of forage (producers) needed to support the moose population in 1997 if the Moose total mass was 862303 . (Hint: Remember the 10% rule.)

• 8623030

• 86230.3

• 9000000

• 720000

Tags

NGSS.MS-LS2-1