Ecology and Climate Change Lectures Review

A comprehensive set of flashcards based on the lecture notes covering ecology and climate change concepts.

What is an ecological niche?

An ecological niche is the role or function of an organism or species within an ecosystem, including its habitat, resource use, and interactions with other organisms.

What is niche overlap?

Niche overlap occurs when two species have similar needs and use the same resources in the same habitat, leading to competition.

Do the niches of two species tend to exactly overlap in nature?

No, niches of two species do not tend to exactly overlap due to resource partitioning.

When does the greatest competition between two species occur?

The greatest competition occurs when species have overlapping niches and are competing for the same limited resources.

How is competition defined?

Competition is defined as the struggle between organisms for the same resources in an ecosystem.

What do different species compete for?

Different species compete for resources such as food, water, space, and mates.

What is the difference between intraspecific competition and interspecific competition?

Intraspecific competition occurs between members of the same species, while interspecific competition occurs between different species.

What is the difference between asymmetric competition and symmetric competition?

Asymmetric competition occurs when one species is more adversely affected than another; symmetric competition occurs when both species are affected equally.

Which is more common in nature – symmetric or asymmetric competition?

Asymmetric competition is more common in nature.

Does competition always involve direct contact or fighting?

No, competition does not always involve direct contact; it can occur through exploitation of resources.

What is competitive exclusion?

Competitive exclusion is the principle that two species competing for the same resource cannot coexist if their niches are identical.

When does competitive exclusion occur?

Competitive exclusion occurs when one species is more efficient than the other at utilizing a limited resource.

What did ecologist Joe Connell observe about two species of barnacle in the intertidal zone?

Connell observed that one species of barnacle occupies higher zones, while another occupies lower zones, indicating niches and competition.

How do barnacles feed?

Barnacles feed by filtering plankton from the water using feathery appendages called cirri.

What experiment did Connell conduct?

Connell conducted experiments to test the effects of competition between two barnacle species.

What hypotheses was Connell testing?

Connell was testing whether competition excluded one species from the other’s niche.

Which of these hypotheses was supported by Connell's results?

His results supported the hypothesis that interspecific competition leads to competitive exclusion.

How can you tell what the effect of an interaction is on a species?

You can determine the effect of an interaction by studying species' population changes in response to the presence or absence of another species.

How do we know which side of the rock was the control in Connell’s experiment?

The control side of the rock showed no experimental manipulation and provided a baseline for comparison.

What is the fundamental niche of a species?

The fundamental niche is the full range of conditions under which a species can survive and reproduce without competition.

What is the realized niche of a species?

The realized niche is the actual conditions and resources a species uses in the presence of competitors.

Which is usually bigger: the fundamental niche or the realized niche?

The fundamental niche is usually bigger than the realized niche.

What is the exception to the general rule regarding niches?

The exception is when a species adapts to utilize its realized niche fully, potentially increasing its role in the ecosystem.

What parts of the intertidal are the fundamental niche of species A?

The fundamental niche of species A includes the entire area it can theoretically occupy without competition.

What are mutualistic interactions?

Mutualistic interactions are relationships between species where both partners benefit in terms of fitness.

What is the impact of the interaction on fitness of both partners?

Both partners in a mutualistic interaction gain increased survival and reproductive success.

What are four key points about mutualisms?

1. They enhance fitness for both species. 2. They can be obligate or facultative. 3. They often involve resource exchanges. 4. They play key roles in ecosystem functioning.

What are Rhizobium bacteria?

Rhizobium bacteria are nitrogen-fixing bacteria that live in root nodules of legume plants.

Where do Rhizobium bacteria live?

They primarily live in the root nodules of legumes.

What do Rhizobium bacteria provide to their host?

They provide nitrogen to their host plants, enhancing their growth.

What do Rhizobium bacteria gain in return?

They gain carbohydrates and an ideal environment for growth from the host plant.

What are mycorrhizal fungi?

Mycorrhizal fungi are fungi that form symbiotic relationships with plant roots.

Where do mycorrhizal fungi live?

They live in the soil and in association with plant roots.

What do mycorrhizal fungi provide to their host?

They provide enhanced nutrient and water absorption.

What do mycorrhizal fungi gain in return?

They gain carbohydrates and other organic substances from the host plant.

How common are mycorrhizal fungi?

Mycorrhizal fungi are extremely common and are found in most terrestrial ecosystems.

Who fixes nitrogen in the ocean?

Certain cyanobacteria and some free-living bacteria fix nitrogen in the ocean.

What has been the impact of mutualisms on land plants?

Mutualisms have significantly enhanced the nutrient uptake and overall fitness of land plants.

What are angiosperms?

Angiosperms are flowering plants that produce seeds enclosed in fruit.

How do angiosperms reproduce?

Angiosperms reproduce through pollination and fertilization processes involving flowers.

What is pollination?

Pollination is the transfer of pollen from male structures to female structures of flowers.

What is fertilization?

Fertilization is the fusion of male and female gametes to form a zygote.

What structure contains the baby plant?

The seed contains the baby plant.

What does 'haploid' mean?

Haploid refers to a cell or organism that has one complete set of chromosomes.

What does 'diploid' mean?

Diploid refers to a cell or organism that has two complete sets of chromosomes.

What is mitosis?

Mitosis is the process of cell division resulting in two identical daughter cells.

What is coevolution?

Coevolution is the process where two or more species influence each other's evolution.

What is notable about the Madagascar comet orchid?

Its structure evolved in conjunction with a specific long-tongued moth, which is essential for pollination.

What does it mean to say a mutualist is 'cheating'?

It means the mutualist is exploiting the relationship without providing the expected benefits.

Under what conditions is the ant-acacia interaction mutualistic?

It is mutualistic when ants protect acacia trees from herbivores.

Under what conditions is the ant-acacia interaction parasitism?

It becomes parasitic when ants damage the acacia more than they protect it.

Within Domain Eukarya, which groups have been influenced by endosymbiosis?

Plants, fungi, and animals have all been influenced by endosymbiosis.

What kinds of organisms are photosynthetic but are not plants?

Certain algae and some types of bacteria (e.g., cyanobacteria) are photosynthetic but not plants.

What type of organism has the most similar DNA to mitochondrion?

The most similar DNA to mitochondrion is found in proteobacteria.

What type of organism has the most similar DNA to chloroplast?

The most similar DNA to chloroplast is found in cyanobacteria.

Which came first, the mitochondrion or the chloroplast?

The mitochondrion came first, as indicated by evolutionary history.

How do you know the order of mitochondrion and chloroplast?

Mitochondria are found in all eukaryotic cells, while chloroplasts are found only in plants and algae.

What key pieces of evidence support the endosymbiosis theory?

Evidence includes similarities in DNA, double membranes, and similarities to prokaryotic cell structures.

What cellular functions are carried out by mitochondria and chloroplasts?

Mitochondria carry out cellular respiration; chloroplasts conduct photosynthesis.

What does the direction of an arrow in a food web mean?

The direction of an arrow indicates the flow of energy or nutrients.

Which direction should food web arrows point, and what do those arrows represent?

Arrows point towards the organism that receives energy, representing the flow from prey to predator.

What do the prefixes photo- and chemo- mean?

Photo- refers to light; chemo- refers to chemical.

What do the prefixes auto- and hetero- mean?

Auto- means self; hetero- means other or different.

What groups of organisms are often missing from food web drawings?

Decomposers and detritivores are often missing from food web drawings.

Why aren’t wolves classified as ecosystem engineers, but beavers are?

Wolves indirectly influence populations but do not physically alter habitats like beavers do.

How do you assign an organism in a food web to the category primary producer?

Primary producers are identified as organisms that produce their own energy, typically through photosynthesis.

What about primary, secondary, and tertiary consumers?

Primary consumers eat primary producers, secondary consumers eat primary consumers, and tertiary consumers eat secondary consumers.

How do trophic omnivores differ from primary, secondary, and tertiary consumers?

Trophic omnivores eat at multiple levels in the food web, rather than being restricted to one type of consumer.

What are direct and indirect effects?

Direct effects are immediate interactions; indirect effects are the consequences of those interactions on other species.

Describe the effects that at least 3 different organisms in the food web can have on moose populations.

1. Wolves reduce moose populations. 2. Trees' growth improves when wolves control moose numbers. 3. Increased vegetation from fewer moose may attract herbivores.

How is a trophic cascade different from a change at the primary producer or primary consumer level?

A trophic cascade affects multiple levels in a food web, whereas changes at lower levels primarily impact those directly involved.

How does a trophic cascade diagram differ from a food web?

A trophic cascade diagram shows direct and indirect effects across multiple levels, while a food web shows interactions at a fixed point.

At Yellowstone, how did prey behavior affect primary producer populations?

Prey behavior changed due to wolf reintroduction, leading to increased vegetation growth in previously overbrowsed areas.

Why do we classify the tree shrew – pitcher plant interaction as mutualism?

Because both benefit from the relationship: the tree shrew gets shelter while the pitcher plant receives nutrients from droppings.

In a trophic pyramid, where is the amount of energy the highest?

The amount of energy is highest at the base, where primary producers are located.

How does the amount of energy change from the base to the top of a food web?

Energy decreases from the base to the top due to energy loss at each trophic level.

What limits the number of trophic levels in an ecosystem?

Energy availability limits the number of trophic levels.

Why can we measure energy in both units of mass and units of energy?

Energy can be represented as mass (e.g., kg) to show biological growth or as energy units (e.g., kcal) to show energy content.

How do we measure and calculate trophic efficiency?

Trophic efficiency is calculated by measuring energy transfer between trophic levels and is usually expressed as a percentage.

Describe real-life examples of CE, AE, and PE.

1. Consumption Efficiency (CE): How much energy is consumed by a predator. 2. Assimilation Efficiency (AE): Energy absorbed by the predator after consumption. 3. Production Efficiency (PE): Energy that contributes to growth.

How does cellular respiration relate to trophic efficiency?

Cellular respiration indicates the efficiency of energy use; higher respiration means less energy available for the next trophic level.

Why is > 80% of land used for livestock, yet it corresponds to just 18% of calories in food?

Land is used inefficiently by livestock, resulting in high resource inputs with low caloric yields.

How do keystone species differ from dominant species?

Keystone species have a disproportionate impact on their ecosystem relative to their abundance, while dominant species are the most abundant in terms of numbers.

What are some examples of both dominant and keystone species?

Dominant species include grass in prairies; keystone species include wolves in Yellowstone.

What was the experimental design for Bob Paine’s experiment on Pisaster in the intertidal zone?

He removed Pisaster and observed the impacts on mussel populations to study keystone predation.

What did the results of this experiment show?

The removal of Pisaster caused mussels to dominate, reducing biodiversity.

What are some ways that parasites can influence food webs?

Parasites can alter host behavior, population dynamics, and nutrient cycling.

What are some reasons why we should care about energy flow and primary production?

Energy flow and primary production are crucial for ecosystem health, food security, and understanding ecological dynamics.

What are some cases where we want to promote primary production?

Promoting primary production is essential in agriculture and forest management.

What are some cases where there is too much primary production?

Eutrophication leads to excessive algal blooms harming aquatic environments.

What are the four components of an ecosystem that are linked by energy flow?

Producer, consumer, decomposer, and abiotic components.

Where does the energy that flows through a food web usually come from?

Energy usually comes from the sun, captured by primary producers during photosynthesis.

Which organisms 'capture' that energy when it enters a food web?

Primary producers, such as plants and phytoplankton, capture energy.

What do the food web arrows indicate?

They indicate the direction of energy and nutrient flow between organisms.

How can you identify something as a primary producer?

Primary producers can be identified by their ability to create energy through photosynthesis.

What happens to the energy in a top predator when it dies?

The energy stored in a top predator is released back into the ecosystem through decomposition.

Do primary producers use that energy?

No, primary producers do not use the energy from dead top predators; it is used by decomposers.

What does the 'auto' prefix on a word refer to?

'Auto' refers to self-sustaining or self-produced.

What about 'hetero'?

'Hetero' refers to other or different sources.

What does 'organic' mean?

Organic refers to molecules containing carbon, typically derived from living organisms.