3B5 Ecology

Question 1

What is the biosphere?

Answer 1

The zone where life exists on Earth.

This includes land, water, and air, where all living organisms are found.

Question 2

What is an organism?

Answer 2

A single living entity.

Organisms include plants, animals, fungi, and microorganisms.

Question 3

Define:

Population

Answer 3

A group of individuals of the same species in a specific area.

Populations interact and reproduce within their environment.

Question 4

True or False:

A population can consist of different species.

Answer 4

False

A population consists of individuals of the same species.

Question 5

What is a community?

Answer 5

A group of interacting species in a specific area.

Communities are formed by various populations coexisting in a habitat.

Question 6

What is an ecosystem composed of?

Answer 6

A community interacting with its environment.

Ecosystems include both living (biotic) and non-living (abiotic) factors like water, temperature, and sunlight.

Question 7

Fill in the blank:

The ________ biome is the largest biome on Earth.

Answer 7

oceanic

Oceans cover more than 70% of the Earth’s surface and are the largest biome.

Question 8

What determines the type of biome found in a region?

Answer 8

Climate factors like temperature and precipitation.

The climate influences the types of plants and animals that can thrive in a biome.

Question 9

What role do primary producers play in an ecosystem?

Answer 9

They produce energy through photosynthesis.

Producers, like plants and algae, are the foundation of the food chain.

Question 10

True or False:

All ecosystems are the same size.

Answer 10

False

Ecosystems can vary greatly in size, from small ponds to large forests.

Question 11

What is a niche in an ecosystem?

Answer 11

An organism’s role and interactions within its environment.

This includes how it obtains food, reproduces, and interacts with other species.

Question 12

What is the main function of decomposers in an ecosystem?

Answer 12

To break down dead organic matter.

Fungi and bacteria recycle nutrients, maintaining the flow of energy.

Question 13

Fill in the blanks:

An ecosystem consists of both ________ and ________ factors.

Answer 13

biotic; abiotic

Biotic factors are living components, while abiotic factors are non-living elements like water and soil.

Question 14

What is the relationship between populations and communities?

Answer 14

Populations make up communities.

A community consists of multiple populations of different species living and interacting in the same area.

Question 15

True or False:

A community includes only populations of the same species.

Answer 15

False

A community includes populations of different species.

Question 16

What are intraspecific relationships?

Answer 16

Interactions between individuals of the same species.

These relationships can be positive, negative, or neutral, affecting the survival and reproduction of the individuals involved.

Question 17

What is competition in intraspecific relationships?

Answer 17

It is when individuals of the same species compete for limited resources.

Resources such as food, shelter, and mates are often limited, leading to competition for their acquisition.

Question 18

True or False:

Intraspecific competition can lead to the elimination of weaker individuals.

Answer 18

True

Individuals that cannot access resources may not survive or reproduce, reducing their numbers.

Question 19

What is altruism?

Answer 19

When an individual helps another at a cost to itself.

This behavior is often seen in cooperative species where helping others improves the overall survival of the group or species.

Question 20

How does altruism benefit a species?

Answer 20

It can boost group survival and improve the chances of passing on genes.

Altruistic behaviors can increase the fitness of relatives, known as kin selection, or of the group as a whole.

Question 21

Fill in the blank:

Altruistic behavior often involves __________ to help others at the cost of an individual’s own resources or safety.

Answer 21

self-sacrifice

This self-sacrifice may increase the reproductive success of others in the group, particularly relatives.

Question 22

True or False:

Altruistic behavior can sometimes be directed toward non-relatives in some species.

Answer 22

True

In some cases, individuals may help non-relatives, which can indirectly increase the chances of their own survival or future reproductive success.

Question 23

What is territoriality?

Answer 23

The defense of a specific area against others of the same species.

This behavior is often related to securing resources like food, mating opportunities, or nesting sites.

Question 24

How does territoriality impact intraspecific interactions?

Answer 24

It reduces competition by granting exclusive access to resources.

Territorial behaviors can help individuals avoid costly conflicts over resources.

Question 25

# Fill in the blank: \_\_\_\_\_\_\_\_\_ is a **behavior** in which one individual helps another, sometimes at a cost to itself, in hopes that the favor will be returned.

Answer 25

Reciprocity ## Footnote **Reciprocity** in intraspecific relationships is common in social species where individuals exchange favors.

Question 26

# True or False: Competition **only** occurs during times of resource scarcity.

Answer 26

False ## Footnote Competition can occur **anytime** resources are limited or when individuals vie for mates or territory.

Question 27

What is the **outcome** of intense intraspecific competition?

Answer 27

It may lead to **natural selection**. ## Footnote Intense competition drives evolutionary changes as individuals with advantageous traits are more likely to survive and reproduce.

Question 28

# Define: Interspecific relationships

Answer 28

Interactions between individuals of **different** species. ## Footnote These relationships can affect the survival, reproduction, and distribution of species in an ecosystem.

Question 29

What is **mutualism**?

Answer 29

A relationship where **both** species benefit. ## Footnote Both species provide something *beneficial* to each other, such as food or protection.

Question 30

How does mutualism **benefit** both species?

Answer 30

Both species **gain** resources or protection, enhancing survival. ## Footnote An example is the *relationship* between bees and flowers: bees get nectar, and flowers get pollinated.

Question 31

# True or False: Mutualism can **only** occur between plants and animals.

Answer 31

False ## Footnote Mutualism can occur between *different* types of organisms, including plants, animals, and microorganisms.

Question 32

# Fill in the blank: In parasitism, the \_\_\_\_\_\_\_\_ benefits at the **expense** of the host.

Answer 32

parasite ## Footnote **Parasitism** is a harmful relationship for the host but beneficial for the parasite, which gains nutrition or shelter.

Question 33

What **type** of relationship involves one species benefiting while the other is unaffected?

Answer 33

Commensalism ## Footnote An example is barnacles attaching to the skin of whales; the barnacles gain mobility and access to nutrient-rich water, while the whale is unaffected.

Question 34

How does commensalism **differ** from mutualism?

Answer 34

In commensalism, one species benefits, while in mutualism, both benefit. ## Footnote **Commensalism** doesn't provide any benefit or harm to the other species involved, unlike **mutualism** where both gain advantages.

Question 35

What is an **example** of mutualism?

Answer 35

Birds **eating** ticks off large mammals. ## Footnote The bird gains a food source (ticks), while the mammal benefits by having parasites removed, improving its health.

Question 36

# True or False: In commensalism, the benefiting species **always** improves the survival of the other species.

Answer 36

False ## Footnote In commensalism, the other species is **neither** helped nor harmed, so there is no impact on its survival.

Question 37

What is **predation**?

Answer 37

A relationship where one species hunts and consumes another for food. ## Footnote This is common in ecosystems and plays a crucial role in regulating populations.

Question 38

# Fill in the blank: In predation, the ________ **benefits** from hunting and consuming the prey.

Answer 38

predator ## Footnote **Predators** are usually adapted to capture and kill prey, often with specialized hunting techniques or physical features.

Question 39

# True or False: Parasitism is **always** harmful to the host species.

Answer 39

True ## Footnote Parasitism harms the host by taking resources or causing disease, which can reduce the host's fitness.

Question 40

What does the term **coevolution** refer to?

Answer 40

The process by which two species **influence** each other's evolution. ## Footnote Coevolution often occurs in predator-prey and mutualistic relationships, where changes in one species lead to adaptations in the other.

Question 41

What is a predator's **role** in an ecosystem?

Answer 41

They **control prey populations**, maintaining ecosystem balance. ## Footnote By controlling prey numbers, predators prevent overpopulation and the depletion of resources.

Question 42

What is a **mutualistic** relationship between fungi and plants called?

Answer 42

Mycorrhizal symbiosis. ## Footnote Fungi *provide* plants with nutrients from the soil, and in return, plants supply fungi with sugars produced during photosynthesis.

Question 43

# True or False: Commensalism is **always** a permanent relationship.

Answer 43

False ## Footnote Commensal relationships can **change** over time, especially if environmental conditions change or if the relationship evolves into mutualism or parasitism.

Question 44

What is an example of **parasitism**?

Answer 44

A **tapeworm** living in the intestines of a mammal. ## Footnote The tapeworm *absorbs* nutrients from the host's food, depriving the host of those nutrients.

Question 45

How can parasitism **lead** to evolutionary changes in species?

Answer 45

Hosts **develop** defenses, while parasites improve exploitation. ## Footnote This ongoing *arms race* can drive adaptations in both the parasite and host species.

Question 46

What are the **biotic** components of an ecosystem?

Answer 46

The **living** components, such as plants, animals, and microorganisms. ## Footnote Biotic components interact with each other and influence ecosystem dynamics through predation, competition, and symbiotic relationships.

Question 47

What are the **abiotic** components of an ecosystem?

Answer 47

**Non-living** components, like sunlight, temperature, water, and soil. ## Footnote Abiotic *factors* determine the types of organisms that can live in an ecosystem, as they influence survival and reproduction.

Question 48

# Fill in the blank: Biotic and abiotic components **interact** in an ecosystem by \_\_\_\_\_\_\_\_\_\_ each other to regulate the ecosystem.

Answer 48

influencing ## Footnote For *example*, plants (biotic) depend on water and sunlight (abiotic) for photosynthesis, while animals (biotic) rely on plants for food.

Question 49

# True or False: Two species can have the **same** niche in an ecosystem without competing.

Answer 49

False ## Footnote If two species occupy the same niche, they must *compete* for the same resources, which can lead to one species outcompeting the other.

Question 50

What is **resource availability** in an ecosystem?

Answer 50

The availability of resources like food, water, and shelter to species. ## Footnote Resource availability directly impacts population sizes, as species need these resources for survival and reproduction.

Question 51

What are limiting **factors** in an ecosystem?

Answer 51

Factors that **limit** population growth, like food, predation, and climate. ## Footnote Limiting factors *determine* the carrying capacity of an environment, meaning they control how many individuals the ecosystem can support.

Question 52

# True or False: Only abiotic factors can **limit** population growth.

Answer 52

False ## Footnote **Both** biotic (e.g., competition, predation) and abiotic (e.g., temperature, water availability) factors can limit population growth.

Question 53

# Define: Carrying capacity

Answer 53

The **largest population** an environment can support. ## Footnote When a population exceeds its carrying capacity, resources become strained, leading to competition and a decrease in population size.

Question 54

# Fill in the blank: Critical population size is the \_\_\_\_\_\_\_\_ **number** of individuals required for a population to survive and reproduce successfully.

Answer 54

minimum ## Footnote Below this size, a population may face a high risk of **extinction** due to inbreeding, reduced genetic diversity, or other environmental factors.

Question 55

# True or False: A population can thrive **without** reaching its critical population size.

Answer 55

False ## Footnote If a population falls below its critical population size, it may not be able to *recover* and could face extinction.

Question 56

How does predation **impact** population sizes?

Answer 56

It **reduces** prey populations and helps maintain ecosystem balance. ## Footnote Predators regulate prey populations by removing individuals from the ecosystem, which can indirectly affect the growth of other species.

Question 57

What is the **process of energy transfer** in an ecosystem?

Answer 57

Energy flow ## Footnote *Energy* enters ecosystems through sunlight, which plants (producers) use for photosynthesis. Consumers and decomposers transfer energy through food webs.

Question 58

# True or False: Energy flows in a **circular** pattern within an ecosystem.

Answer 58

False ## Footnote Energy flows in **one** direction, from producers to consumers to decomposers, and is eventually lost as heat.

Question 59

What is the **variety** of species, genes, and ecosystems in an area?

Answer 59

Biodiversity ## Footnote High biodiversity promotes ecosystem **stability** by enhancing resilience to disturbances and supporting a variety of ecosystem services.

Question 60

What is **ecological succession**?

Answer 60

The **change in species structure** of an ecological community over time. ## Footnote Succession occurs in *stages*: primary succession starts in a barren environment, while secondary succession occurs after a disturbance in an existing community.

Question 61

# True or False: Ecological succession **always** results in the same stable community.

Answer 61

False ## Footnote Succession may lead to **different** stable communities depending on factors such as climate, soil, and species interactions.

Question 62

What is **phenology**?

Answer 62

The study of the **timing** of natural events. ## Footnote Phenological events are influenced by seasonal changes and climate, and shifts in phenology can indicate environmental changes.

Question 63

What is the **nitrogen cycle**?

Answer 63

The **flow of nitrogen** from the atmosphere to soil and organisms. ## Footnote Nitrogen is fixed by bacteria, absorbed by plants, and passed on to animals. Decomposers return nitrogen to the soil in the form of ammonia.

Question 64

# Fill in the blank: The carbon cycle involves the **movement** of \_\_\_\_\_\_ between the atmosphere, oceans, and living organisms.

Answer 64

carbon ## Footnote The *carbon cycle* is crucial for regulating Earth's climate and involves processes like photosynthesis, respiration, and decomposition.

Question 65

How does the carbon cycle **impact** global climate?

Answer 65

It **regulates** atmospheric carbon dioxide, affecting global temperatures. ## Footnote Excess carbon in the atmosphere, from activities like burning fossil fuels, contributes to global warming by enhancing the greenhouse effect.

Question 66

What is **climate change**?

Answer 66

Long-term **shifts** in temperature and weather patterns. ## Footnote Climate change is primarily driven by human activities like burning fossil fuels, which release greenhouse gases.

Question 67

# True or False: Climate change can **lead** to more frequent droughts and floods.

Answer 67

True ## Footnote The **disruption** of weather patterns due to climate change can lead to more extreme and unpredictable weather events.

Question 68

What is **ocean acidification**?

Answer 68

**Decrease in ocean pH** due to absorbed carbon dioxide. ## Footnote Ocean acidification *impacts* marine organisms like corals and shellfish, which rely on calcium carbonate.

Question 69

What are **cascading effects** in ecosystems?

Answer 69

Secondary changes **triggered** by an initial disturbance. ## Footnote An example is the loss of pollinators, leading to decreased plant reproduction, affecting herbivores and predators.

Question 70

# True or False: Cascading effects occur **only** in large-scale disturbances.

Answer 70

False ## Footnote They can occur in response to *small* or *medium* disturbances.

Question 71

What is a **keystone** species?

Answer 71

A species that has a **disproportionately large** effect on its ecosystem. ## Footnote For example, *sea otters* control sea urchin populations, preventing overgrazing of kelp forests and preserving the marine ecosystem's balance.

Question 72

# Fill in the blank: Invasive species are \_\_\_\_\_\_\_\_ species that **harm** local ecosystems.

Answer 72

non-native ## Footnote Invasive species can **outcompete** native species, reducing biodiversity.

Question 73

How do invasive species **alter** ecosystems?

Answer 73

By **outcompeting** native species and altering environmental conditions. ## Footnote They can change food webs and displace native organisms.

Question 74

What causes ecosystem **disturbances**?

Answer 74

* Natural events * Human activities ## Footnote Both can **disrupt** habitats and species populations. Human activities can include pollution or deforestation, while natural events could include earthquakes or wildfires.

Question 75

What is a direct **consequence** of deforestation on ecosystems?

Answer 75

Loss of habitat and decreased **biodiversity**. ## Footnote Deforestation disrupts ecosystems by destroying habitats for many species, leading to population declines and loss of biodiversity.

Question 76

What is the role of **pollinators** in ecosystems?

Answer 76

They **facilitate plant reproduction** by transferring pollen. ## Footnote Pollinators are essential for the reproduction of many crops and wild plants.

Question 77

# True or False: The **loss** of pollinators would have a massive effect on ecosystems.

Answer 77

True ## Footnote It would severely disrupt plant reproduction and the food web.

Question 78

How does ocean warming **impact** marine ecosystems?

Answer 78

It **leads** to coral bleaching and disrupts marine food webs. ## Footnote Warmer waters cause corals to expel algae, vital for their survival and food.

Question 79

# Fill in the blank \_\_\_\_\_\_\_\_ species are those that **naturally** occur in a specific habitat or environment.

Answer 79

Native ## Footnote **Native** species are adapted to the local environment and play important roles in maintaining ecosystem balance.

Question 80

# True or False: Ecosystem disturbances **always** result in permanent damage.

Answer 80

False ## Footnote Many ecosystems can **recover** over time, especially if disturbances are moderate and the area has high biodiversity.