Ensci_ midterm review_ fall 2024

Ensci Midterm Review:

Fall 2024

Use this to help you complete your midterm review packet :)

Section 1: Vocabulary and Conceptual Understanding

In ecology, a "population" refers to a group of individuals belonging to the same species that live in a particular area and can interbreed with each other, essentially meaning they are capable of reproducing with one another within that geographic region

Define the term "population" in an ecological organization context. Provide examples from different ecosystems.

Biological organization helps ecologists understand ecosystems by providing a structured hierarchy to study living organisms and their interactions within an environment, allowing them to examine specific levels of complexity, from individual organisms to entire populations, communities, and ultimately the ecosystem as a whole, which enables focused research on particular ecological processes and relationships within a given environment

How does the use of Biological Organization help ecologists understand ecosystems?

Multiple Choice

All the alligators in a swamp are an example of a(n) _______________.

• organism

• community

• population

• group

Multiple Choice

The correct order of ecological organization from the smallest to the largest is _______________.

• organism, community, population, ecosystem, biosphere, biome
• biosphere, biome, ecosystem, community, population, organism
• organism, population, community, ecosystem, biome, biosphere
• population, organism, biosphere, community, ecosystem, biome

Multiple Choice

The people in this picture represent which level of environmental organization. 

• Organisms 
• Community
• Biosphere
• Population 

Multiple Choice

When all the ecosystems on Earth are combined it is called...

• a community.
• a biome.
• a biosphere.
• an Earthsphere.

Multiple Choice

A (or more than one) biotic community plus the abiotic features.

• Population
• Community
• Ecosystem
• Biome

Multiple Choice

What term best describes this group of bison?

• Species
• Community
• Ecosystem
• Population

Multiple Choice

What term best describes all the plants and animals in this image?

• Species
• Population
• Ecosystem
• Community

Multiple Choice

Which DOES NOT represent an Ecosystem?

• A

• B

• C

• D

Biotic factors refer to all living organisms within an ecosystem, like plants, animals, and bacteria, while abiotic factors are the non-living components of the environment, such as sunlight, temperature, water, and soil.

Compare and contrast biotic and abiotic factors. Provide examples specific to forest ecosystems.

Sunlight and water, as abiotic factors in a pond ecosystem, significantly impact the biotic community by directly influencing the growth of primary producers like algae and plants through photosynthesis, which in turn determines the abundance and diversity of organisms throughout the food web, from small invertebrates to larger fish, depending on the availability of light and water quality; essentially, the amount of sunlight dictates the rate of plant growth, while water availability controls the overall health and distribution of all aquatic organisms in the pond.

How do abiotic factors like sunlight and water impact the biotic community in a pond ecosystem?

Multiple Choice

What are biotic factors in an ecosystem?

• The temperature of an ecosystem

• Non-living things in an ecosystem such as rocks and water

• The amount of sunlight an ecosystem receives

• Living things in an ecosystem such as plants, animals, fungi, and bacteria.

Multiple Choice

How do biotic and abiotic factors interact in an ecosystem?

• Biotic factors have complete control over the distribution and abundance of abiotic factors in an ecosystem

• Biotic and abiotic factors interact in various ways, such as through dependence on abiotic factors for survival and through the influence of abiotic factors on the distribution and abundance of biotic factors.

• Biotic factors have no impact on abiotic factors in an ecosystem

• Abiotic factors are solely responsible for the survival of biotic factors in an ecosystem

Multiple Choice

What is the main difference between biotic and abiotic factors?

• Visible vs invisible components

• Living organisms vs non-living physical and chemical components

• Natural vs man-made components

• Living organisms vs non-living organisms

The nitrogen cycle is a biogeochemical process where atmospheric nitrogen gas is converted into forms usable by living organisms, primarily through the action of bacteria which fix nitrogen into ammonia and later decompose organic matter, releasing nitrogen back into the soil as usable compounds like nitrate and nitrite; this cycle involves key steps like nitrogen fixation, nitrification, and denitrification, with bacteria playing a crucial role in each stage.

DESCRIBE the nitrogen cycle, focusing on the roles of bacteria in nitrogen fixation and decomposition.

• Photosynthesis is the primary process that removes carbon dioxide from the atmosphere and stores it in organic compounds within plants . 

• Cellular respiration in both plants and animals releases carbon dioxide back into the atmosphere . 

• The ocean acts as a significant carbon sink, absorbing large amounts of carbon dioxide . 

LABEL this diagram of the carbon cycle, highlighting how respiration and photosynthesis move carbon between reservoirs.

Multiple Choice

How do animals get the nitrogen they need?

• From the air they breathe

• From the water they drink

• From the food they eat

• From the sun

Multiple Choice

Bacteria fix nitrogen from the atmosphere into a form plants can use.

• True

• False

Multiple Choice

What is the process where bacteria turns Nitrogen gas from the atmospheres into usable compounds?

• nitrogen composition

• nitrogen fixation

• ammonia

• denitrification

Multiple Choice

What happens when organisms die and decay? 

• Their bodies are lifted up and decompose in the atmosphere

• Their nitrogen returns to the soil through decomposers

• They keep their nitrogen and don't decompose

• They stay on earth forever as fossil fuels

Multiple Choice

Which of the following removes carbon from the atmosphere?

• Combustion
• Respiration
• Photosynthesis
• Death

Multiple Choice

Which describes the relationship between plants and animals in the carbon cycle?

• Plants produce and release oxygen that animals need

• Plants produce and release carbon dioxide that animals need

• Animals produce and release oxygen that plants need

• Animals produce oxygen that plants turn into carbon dioxide

Multiple Choice

Respiration is the process by which animals take in _____ and release _____. 

• photosynthesis, air
• carbon, oxygen
• oxygen
• oxygen, carbon dioxide

Multiple Choice

Which statement is an example of how carbon moves through a food chain as part of the cycle?

• Producers release carbon dioxide, and consumers take it it.

• Producers take in carbon dioxide, and consumers release it.

• Producers take in carbon from the soil, and they release it when they decompose.

• Producers release carbon into the soil, and consumers take it in from the soil.

Energy decreases as it moves up trophic levels because at each step in a food chain, a significant portion of the energy is lost as heat due to metabolic processes like respiration and digestion, meaning only a small percentage of the energy from one level is transferred to the next, resulting in progressively less energy available at higher trophic levels; this is often referred to as the "10% rule" where roughly only 10% of energy moves from one level to the next. 

EXPLAIN why energy decreases as it moves up trophic levels.

There are fewer apex predators in an ecosystem compared to primary consumers because of the energy pyramid concept in ecology; as energy moves up the food chain, only a small percentage is transferred to the next level, meaning there is significantly less energy available to support a large population of top predators compared to the large base of primary consumers feeding directly on producers.

Why are there fewer apex predators in an ecosystem compared to primary consumers?

Multiple Choice

If 25,000 kg of vegetation is planted in this ecosystem, how would the lion population change?

• Decrease by 2,500 kg
• Decrease by 25,000 kg
• Increase by 250 kg
• Increase by 250,000

Multiple Choice

The primary consumer receives 400 kj of energy from the producer. How much energy will the secondary consumer receive?

• 40

• 4000

• 400

• 4

Multiple Choice

How much energy is passed on to each trophic level in an energy pyramid?

• 10%
• 90%
• 50%
• 80%

Multiple Choice

Why can't the top level contain a large number of organisms?

• Because as energy moves from the bottom to the top level, less and less energy is available to higher levels.
• Because the original energy from producers is the total energy available to all the organisms in the energy pyramid.
• because only about ten percent of the energy available at one level is transferred to the next level.
• all of the above

The main difference between a food chain and a food web is that a food chain is a linear sequence of organisms, while a food web is a complex network of interconnected food chains

Complete the food web below by drawing the arrows. Write 3 food chains in the food web.

If all deer were to disappear from this ecosystem, the most immediate impact would be a significant decrease in the populations of predators that rely on deer as a primary food source, like wolves and mountain lions, likely leading to their decline in numbers due to lack of prey. This would then cause a cascading effect throughout the food web, leading to an increase in the plant population that deer typically feed on (like grasses and shrubs), potentially impacting the diversity of plant life by allowing certain species to dominate, while simultaneously decreasing the populations of smaller herbivores that might compete with deer for the same plants.

ANALYZE the food web chart and DESCRIBE what would happen to the ecosystem if all of the deer were to disappear from the ecosystem.

Multiple Choice

Which of the following best explains why energy transfer between trophic levels is inefficient?

• Energy is lost as heat during metabolic processes.

• Energy is destroyed during transfer.

• Energy is converted into water.

• Energy is stored indefinitely in organisms.

Multiple Choice

How do food web interactions affect ecosystem stability?

• They decrease biodiversity and ecosystem resilience.

• They increase competition and reduce resource availability.

• They enhance biodiversity and contribute to ecosystem resilience.

• They have no impact on ecosystem stability.

Multiple Choice

Based on the food web shown above, which of the following is most likely responsible for the rabbit population trend as shown in the graph? 

• increase in amount of grass
• decrease in amount of grass
• overpopulation in squirrel population
• increase in rabbit population

Multiple Choice

What may happen if the snowshoe hare was removed from the food web pictured?

• The insects in the habitat would increase.
• The shrew population would decrease due to being only hawk food source.
• The willow tree population would decrease.
• Foxes would dies due to no food source. 

Multiple Choice

Use the diagram to answer the question.
The Mayfly is a food source for which 3 organisms?

• Frog, Dragon Fly and snake
• Frog, trout and dragon fly
• Frog, salamander and trout
• Frog and phytoplankton

Multiple Choice

Identify the correct food chain that demonstrates the energy flow of this food web

• Plant > Caterpillar > Bluebird > Eagle
• Plant > Lizard > Snail
• Plant >Lizard > Snail >Eagle
• Eagle >Lizard>Caterpillar>Plant

Adaptations are specific physical characteristics or behaviors that organisms develop over time through evolution, allowing them to better survive and reproduce in their particular environment by providing advantages like accessing food, evading predators, or coping with extreme conditions; for example, a polar bear's thick fur helps it insulate against cold temperatures, while a desert cactus's spines protect it from herbivores and its fleshy stem stores water during dry periods. 

EXPLAIN how specific adaptations (e.g., white fur in polar bears) help organisms survive in their environment.

If an organism's environment shifts drastically due to deforestation or climate change, its role in the ecosystem could change significantly, potentially leading to population decline, migration to new areas, altered feeding patterns, or even extinction, depending on its ability to adapt to the new conditions; for example, a tree-dwelling species might need to find new food sources or shelter if its habitat is cleared, while a species sensitive to temperature changes might need to migrate to cooler regions to survive. 

PREDICT how an organism’s role in its ecosystem might change if its environment shifts drastically (e.g., deforestation or climate change).

Multiple Choice

Biodiversity, aka biological diversity, usually refers to

• the number of people on Earth

• the variety of species on Earth

• the number of animal species in a specific area

• the number of plant species in a specific area

Multiple Choice

The lionfish is a venomous fish found primarily in the Red Sea and the Indian Ocean. In the 1990s, lionfish were accidentally released into the Atlantic Ocean, where they found abundant resources and favorable environmental conditions. Which of the following scenarios is most likely to result in the lionfish having a major impact on the communities into which they were introduced?

• With no natural predators, the lionfish population will become very large.

• Some native species of invertebrates will develop a resistance to lionfish venom.

Multiple Choice

1. What is an adaptation?

• A feature or behavior that helps an animal survie.
• The food that an animal eats.
• How energy moves in a food web.

Multiple Choice

 Which of these BEST describes how some birds survive when the weather gets cold? 

     

•  a.   They store twigs and sticks in their nest 
•  b. They migrate to a warmer climate 
•  c. They grow more feathers to stay warm in the winter 
•  d. They hide in bushes and wait for warm weather 

Multiple Choice

Why is the mouse population changing over time?

• The light mice can reproduce more successfully than the dark mice

• The hawks eat more dark mice than light mice because the dark mice taste better

• The hawks eat more light mice than dark mice because they can see the light mice more easily

• The hawks eat more dark mice than light mice because they can see the dark mice more easily

Primary and secondary succession are both ecological processes where a community of organisms gradually changes over time, but the key difference lies in the initial conditions: primary succession occurs in areas with no existing soil or life, like newly formed volcanic rock, while secondary succession happens in a previously disturbed area where some soil and life forms already exist, such as after a wildfire or logging operation.

DESCRIBE the similarities and differences between primary and secondary succession. Provide examples of each.

Primary and secondary succession are both ecological processes where a community of organisms gradually changes over time, but the key difference lies in the initial conditions: primary succession occurs in areas with no existing soil or life, like newly formed volcanic rock, while secondary succession happens in a previously disturbed area where some soil and life forms already exist, such as after a wildfire or logging operation.

DESCRIBE the similarities and differences between primary and secondary succession. Provide examples of each.

Multiple Choice

After a forest fire, an ecosystem would start regrowth through -

• primary succession

• secondary succession

• climax community

• limiting factors

Multiple Choice

Which of the following best describes primary succession?

• Volcano wipes out ecosystem that gradually grows back from ash covered soil

• Volcano creates a new island of rock that must break down to form an ecosystem

• Forest fire burns down forest that must bounce back over time

• Tornado destroys a crop that must slowly grow back over time.

Multiple Choice

Which progression best explains secondary succession?

• lichens>grass>shrubs>small trees> big trees

• mosses>creates soil>grasses>small trees> big trees

• Fire destroys ecosystem>grasses>shrubs>small trees>big trees

• Volcano forms new island> lichens>grasses>shrubs>small trees>big trees

Explanation Slide...

The question asks for the best explanation of secondary succession. The correct choice is 'Fire destroys ecosystem>grasses>shrubs>small trees>big trees.' This option highlights the process of fire destroying the existing ecosystem, followed by the growth of grasses, shrubs, small trees, and eventually big trees. The answer explanation is within the limit of 75 words and does not mention the option number. It is important to note that the question is about secondary succession, not the formation of a new island or the creation of soil by mosses.

Volcanic emissions, particularly sulfur dioxide gas, can cause a short-term cooling effect on global temperatures by releasing particles into the stratosphere which reflect sunlight back into space, effectively shading the Earth and lowering surface temperatures for several years following a large eruption; this is due to the creation of sulfate aerosols that act as a reflective barrier to incoming solar radiation. 

DESCRIBE the short-term effects of volcanic emissions on global temperature.

During an El Niño event, the United States typically experiences wetter conditions in the southern regions, particularly along the Gulf Coast, while the northern parts tend to be drier and warmer; conversely, La Niña brings drier conditions to the south and potentially wetter weather to the Pacific Northwest, with overall changes primarily driven by shifts in the jet stream caused by the Pacific Ocean temperature fluctuations.

How might the United States climate change in weather patterns during El Niño and La Niña events?

Multiple Choice

Both El Nino and La Nina have this in common

• Influence birds that migrate over the ocean

• Influence rainy / dry weather world wide

• The weather at the polar regions

• The directions that ships travel in the oceans

Multiple Choice

The image is of a(n):

• El Nino event

• La Nina event

• Non-El Nino (normal conditions)

Multiple Choice

The picture below is of a(n) ____ event.

• Non-El Nino (Normal)

• El Nino

• La Nina

Multiple Choice

In Florida, El Nino impacts our weather by:

• creating larger waves at the beach

• more thunderstorms and crows flying around

• dry and hot

• wetter and more flood-prone

Multiple Choice

In Florida, La Nina impacts our weather by:

• dryer and warmer

• warmer and wetter

• wetter and colder

• more rain and crows flying around

Multiple Choice

During an El Nino year, in North Carolina we will likely have what kind of winter?

• cold and snowy

• hot and dry

• cold and dry

• no change in weather

Multiple Choice

El Nino occurs when the tropical ocean waters are warmer in which ocean?

• Atlantic
• Indian
• Pacific
• Arctic

Eutrophication is a process that occurs when a body of water becomes enriched with nutrients, causing an overgrowth of algae and other aquatic plants

Define Eutrophication:

Agricultural practices can significantly impact local water bodies by introducing pollutants like fertilizers, pesticides, sediment, and animal waste through runoff, which can lead to algal blooms, depleted oxygen levels, disrupted aquatic ecosystems, and reduced biodiversity, ultimately affecting the health of fish and other aquatic life in the water body; this is particularly concerning when improper land management practices like excessive tillage or lack of cover crops are used. 

How do agricultural practices impact ecosystems in local water bodies?

Multiple Select

Too much of a good thing, such as _____________ and _________________nutrients in the lakes and ponds can cause an imbalance resulting in eutrophication

• oxygen

• phosphorus

• xenon

• nitrogen

Multiple Choice

The green plants on the surface of the lake turned out the be algae! There is a sudden increase in the rate of growth of the algae. What would happen next?

• The algae continue to grow due to excess nutrients, and some of the algae die

• The algae would stop growing

• The algae are not affected by the fertilisers

Multiple Choice

How does eutrophication cause the death of aquatic organisms

• the build up of carbon dioxide in the water

• the lack of nitrogen in the water

• the lack of carbon dioxide in the water

• the lack of oxygen in the water

Kudzu—or kuzu (クズ)—is native to Japan and southeast China. It was first introduced to the United States during the Philadelphia Centennial Exposition in 1876 where it was touted as a great ornamental plant for its sweet-smelling blooms and sturdy vines. How does Kudzu affect local plant species?

Propose a plan to mitigate the impact of agricultural runoff on a local lake ecosystem.

For the last 4 questions...

Use your knowledge to answer the last 4 questions on your own. Make sure to show your teacher once you have completed :)