Ecology

Question 1

Define biotic and abiotic

Answer 1

Biotic – living components
Abiotic – non-living components (rocks, clouds, sunshine)

Question 2

organism

Answer 2

one living thing

Question 3

population

Answer 3

group of the same organism living together

Question 4

community

Answer 4

many populations

Question 5

ecosystem

Answer 5

all the living and non-living things in an area

Question 6

ecology

Answer 6

Ecology is the scientific study of the relationships between organisms and their environment, including the interactions between living organisms (biotic factors) and their physical surroundings (abiotic factors).

Question 7

Define exponential growth, logistic growth.

Answer 7

Exponential growth refers to a rapid and unrestricted increase in population size where each generation produces more offspring than the previous one, leading to a continuously accelerating growth rate.

Logistic growth, on the other hand, describes a population growth pattern that starts with exponential growth but slows down as it approaches the carrying capacity of the environment. The carrying capacity is the maximum population size that the environment can sustainably support.

Question 8

What do J shaped and S shaped growth curves represent? What changes in
population size is most common in nature over time?

Answer 8

A J-shaped growth curve represents exponential growth, where the population size increases rapidly and continuously without any constraints. It forms a curve that resembles the letter “J.”

An S-shaped growth curve represents logistic growth, where the population initially experiences exponential growth, but eventually levels off and stabilizes around the carrying capacity of the environment. It forms a curve that resembles the letter “S.”

In nature, populations commonly exhibit a combination of both J-shaped and S-shaped growth patterns. They start with exponential growth but eventually reach a point where resources become limited, leading to a slowdown in growth and a stabilization around the carrying capacity. This pattern is known as a sigmoid growth curve.

Question 9

What is carrying capacity (K) and what is happening at carrying capacity? What innovations has increased the carrying capacity for humans

Answer 9

Carrying capacity (K) refers to the maximum number of individuals of a species that the environment can sustainably support over the long term. At carrying capacity, the population size stabilizes, as the available resources and environmental conditions are sufficient to meet the needs of the population.

Several innovations have increased the carrying capacity for humans. These include advancements in agriculture (such as improved crop yields and irrigation techniques), technological advancements (such as the development of machinery and tools), medical advancements (such as vaccinations and improved healthcare), and the ability to harness energy from non-renewable resources (such as fossil fuels). These innovations have allowed humans to increase food production, extend lifespans, and utilize resources more efficiently, thus increasing the carrying capacity for our species.

Question 10

Define immigration and emigration. Which increases a population and which decreases a population?

Answer 10

Immigration refers to the movement of individuals into a population from another area or region. It increases the population size of the receiving population.

Emigration, on the other hand, refers to the movement of individuals out of a population to another area or region. It decreases the population size of the source population.

In summary, immigration increases a population by adding individuals to it, while emigration decreases a population by removing individuals from it.

Question 11

What are density independent factors that affect population growth? How do these
factors affect populations?

Answer 11

Density-independent factors are environmental factors that affect population growth regardless of population density. These factors include natural disasters (e.g., hurricanes, fires), temperature extremes, and catastrophic events. They affect populations by causing widespread mortality, habitat destruction, reduced reproductive success, or resource scarcity. As a result, population growth is impacted irrespective of the population size or density.

Question 12

What are density dependent factors that affect population growth? How do these
factors affect populations?

Answer 12

Density-dependent factors are environmental factors that influence population growth rates based on the population’s size or density. These factors become more significant as the population density increases. Examples of density-dependent factors include competition for resources (e.g., food, water, shelter), predation, disease, and territoriality. These factors affect populations by increasing competition, reducing available resources, increasing predation or disease transmission rates, and intensifying social interactions. This leads to decreased birth rates, increased mortality rates, or emigration, ultimately regulating population growth in response to population density.

Question 13

Define symbiotic relationships.

Answer 13

Symbiotic relationships happen when members of different species interact closely together in an ecosystem.

Question 14

What do the following symbols represent: +/+, +/-, +/o, -/-?

Answer 14

Mutualism, exploitation, commensalism, and competition.

Question 15

What type of interaction do humans have with bacteria in our gut that help us
digest food?

Answer 15

A mutualistic relationship because the bacteria get food and they help us digest food.

Question 16

Define interspecific competition and intraspecific competition.

Answer 16

Interspecific is when two species compete against one another and Intraspecific is when one species’ individuals compete against each other

Question 17

Define the following ecosystems.
a. Desert
b. Chaparral
c. Forest
d. Estuary
e. Kelp Forest

Answer 17

Desert = Sandy, little rain (less than 25 cm/yr), few plants, hot, dry, more water lost through evaporation than gained through precipitation
Chaparral = Shrubland, Mediterranean climate (mild, wet winters and hot, dry summers), drought-tolerant plants with hard leaves
Forest = Lots of trees (any densely packed area of vegetation may be considered a forest), habitat for organisms
Estuary = Partly enclosed coastal body of brackish (fresh and saltwater mixed) water, one or more river/stream flowing in, with free connection to the open sea
Kelp Forest = Underwater, lots of kelp, most productive and dynamic ecosystem on earth, occur worldwide, smaller areas are called “kelp beds”

Question 18

In an ecosystem how does energy and chemical or nutrients travel through the
ecosystem? Which is cycled through an ecosystem and which flows through an
ecosystem and escapes out as heat?

Answer 18

Energy flows through an ecosystem, changes forms, and escapes out of it as heat. Matter cycles within an ecosystem between the biotic and abiotic components. Matter cycles within an ecosystem between the biotic and abiotic components.

Question 19

What is the ultimate source of energy for life on earth?

Answer 19

The sun.

Question 20

Where is net primary productivity is greatest and least productive in terrestrial and
marine ecosystems

Answer 20

The highest net primary productivity in terrestrial environments occurs in swamps and marshes and tropical rainforests; the lowest occurs in deserts

Question 21

What is the difference between primary and secondary productivity?

Answer 21

So, the primary productivity is the production of organic matter by the producers while secondary productivity is the production of the organic matter by the consumers.

Question 22

What is an energy pyramid? What percentage of food (energy and nutrients) is transferred from one trophic level to the next?

Answer 22

Pyramid that lists apex predators on top all the way down to the producers, only about 10% of the energy is transferred between levels.

Question 23

What are differences between producers and consumers?

Answer 23

Producers gain energy from inorganic means, but consumers eat living things to survive.

Question 24

What is the function of decomposers?

Answer 24

To recycle dead organic matter (detritus) into a usable form for the ecosystem.

Question 25

What are nutrient cycles and understand how the 4 nutrients discussed in class
cycles between the biotic and abiotic components of the ecosystem. How do
nitrogen fixing bacteria help with a specific nutrient cycle?

Answer 25

The nutrient cycle is a system where energy and matter are transferred between living organisms and non-living parts of the environment. (1) Water Cycle or Hydrologic Cycle (2) Carbon-Cycle (3) Nitrogen Cycle (4) Oxygen Cycle. The role of nitrogen-fixing bacteria is to supply plants with the vital nutrient that they cannot obtain from the air themselves.

Question 26

Explain the greenhouse effect.

Answer 26

The trapping of the sun’s warmth in a planet’s lower atmosphere, due to the greater transparency of the atmosphere to visible radiation from the sun than to infrared radiation emitted from the planet’s surface. Essentially just trapping heat.

Question 27

What happened in Love Canal? What are dioxins?

Answer 27

A half-built canal became a dumping site of toxic chemicals by large industrial companies, which then had a town built over it: causing the chemicals to seep into the ground and burn the residents. Dioxin is a highly toxic compound produced as a byproduct in some manufacturing processes, notably herbicide production and paper bleaching. It is a serious and persistent environmental pollutant.

Question 28

Explain what happened when wolves were removed from Yellowstone Park?
What happened after the wolves were re-introduced into Yellowstone Park?

Answer 28

The Willow and Aspen started dying. then …. The Willow and Aspen started livin.

Question 29

What resources do we need from our environment? Are these resources limited?

Answer 29

Food, water, shelter, fuel. Yes they are limited.

Question 30

The human population is over 7 billion. How has this large population impacted
our resources?

Answer 30

By using them and not replacing them

Question 31

What is hydraulic fracking? What is the Flynt water crisis?

Answer 31

Fracking is a well stimulation technique involving the fracturing of bedrock formations by a pressurized liquid. The process involves the high-pressure injection of “fracking fluid” into a wellbore to create cracks in the deep-rock formations through which natural gas, petroleum, and brine will flow more freely. Doing this to get the natural resources that are way deep down embedded within the sediment. The Flint water crisis is a public health crisis that started in 2014 after the drinking water for the city of Flint, Michigan was contaminated with lead and Legionella bacteria due to fracking.

Question 32

producers

Question 33

primary consumer

Answer 33

A primary consumer is an organism that directly feeds on plants or other primary producers. They are the herbivores in the food chain that obtain energy by consuming plant material. Primary consumers play a crucial role in transferring energy from the lower trophic levels to the higher levels. They are typically the second trophic level in a food chain or food web. Examples of primary consumers include rabbits, deer, grasshoppers, and cows.

Question 34

secondary consumer

Answer 34

A secondary consumer is an organism that feeds on primary consumers. They are carnivores that obtain energy by consuming other animals. Secondary consumers are typically the third trophic level in a food chain or food web. They play an important role in transferring energy and nutrients from lower trophic levels to higher trophic levels. Examples of secondary consumers include snakes, wolves, lions, and hawks.

Question 35

tertiary consumers

Answer 35

A tertiary consumer is an organism that occupies the fourth trophic level in a food chain or food web. Tertiary consumers are carnivores that feed on other carnivores. They obtain energy by consuming secondary consumers.

Tertiary consumers are often apex predators, meaning they are at the top of the food chain and have few or no natural predators themselves. They play a critical role in regulating populations of lower trophic levels and maintaining the overall balance of an ecosystem. Examples of tertiary consumers include large predators like sharks, eagles, or killer whales.

Question 36

heterotrophs

Answer 36

consume for food

Question 37

autotrophs

Answer 37

make own food

Question 38

herbivore

Answer 38

A herbivore is an animal that primarily consumes plant material as its main source of nutrition

Question 39

omnivore

Answer 39

An omnivore is an animal that has the ability to consume and digest both plant and animal matter

Question 40

carnivore

Answer 40

A carnivore is an animal that primarily consumes the flesh or meat of other animals as its main source of nutrition. Carnivores have evolved specialized adaptations such as sharp teeth and claws, a well-developed jaw structure, and digestive systems optimized for digesting and assimilating animal tissue.

Question 41

decomposer

Answer 41

A decomposer is an organism that breaks down dead organic matter and waste materials, such as fallen leaves, dead animals, and plant remains, into simpler substances. Decomposers play a vital role in ecosystems by breaking down and recycling nutrients back into the environment, making them available for other organisms to use.

Common examples of decomposers include bacteria, fungi (such as mushrooms), and some species of insects

Question 42

1st trophic level

Answer 42

The first trophic level consists of primary producers. These are organisms, mostly plants, that convert energy from the sun into food through photosynthesis. They form the base of the food chain and provide energy and nutrients for all other trophic levels.

Question 43

2nd trophic level

Answer 43

The second trophic level consists of primary consumers. These are herbivores that directly feed on the primary producers (plants) from the first trophic level. They obtain energy by consuming plant material and are the first level of consumers in the food chain.

Question 44

3rd trophic level

Answer 44

The third trophic level consists of secondary consumers. These are carnivores that feed on the primary consumers from the second trophic level. They obtain energy by consuming other animals. The third trophic level represents the predators that are higher up in the food chain and rely on the energy and nutrients obtained from consuming other consumers.

Question 45

4th trophic level

Answer 45

The fourth trophic level consists of tertiary consumers. These are carnivores that feed on other carnivores from the third trophic level. They obtain energy by consuming other predators. The fourth trophic level represents the top predators in the food chain, and they are often the highest level of consumers in an ecosystem.