Lecture 10 Species Interactions

Bio-120

What are abiotic factors?

Abiotic factors are non-living, physical factors that influence organisms and ecosystems, such as storms, water temperature, salinity, and pollution.

What are limiting factors?

Limiting factors are resources or conditions that slow the growth of populations as they become scarce, including sunlight, space, water, and nutrients.

What are biotic factors?

Biotic factors refer to interactions between living organisms within an ecosystem, such as predation, competition, and parasitism. These interactions regulate populations.

What are the types of species interactions?

Species interactions can be free-living or symbiotic. Key types include predation, competition, mutualism, commensalism, and parasitism.

What is predation?

Predation involves one species (the predator) hunting, killing, and consuming another species (the prey). The predator helps regulate prey population.

What are predator adaptations?

Predator adaptations include cryptic coloration (camouflage), warning coloration (bright colors signaling toxicity), and mimicry (one species mimicking another to avoid predation).

What is cryptic coloration?

Cryptic coloration is camouflage that helps prey hide from predators, making them harder to detect in their environment.

What is warning coloration?

Warning coloration involves bright colors in prey species to signal to predators that they may be toxic or dangerous.

What is mimicry?

Mimicry occurs when one species mimics another species to fool predators, such as a caterpillar mimicking a snake.

What is competition?

Competition occurs when multiple species or individuals seek the same limited resource, which can be either interspecific (between species) or intraspecific (within a species).

What is interspecific competition?

Interspecific competition is competition between different species for the same resources, which can lead to competitive exclusion or species coexistence.

What is intraspecific competition?

Intraspecific competition is competition within the same species, often involving resource acquisition or mate selection.

What is competitive exclusion?

Competitive exclusion occurs when one species outcompetes another for resources, leading to the exclusion of the latter from the resource.

What is species coexistence?

Species coexistence occurs when two species share resources at a stable population ratio without excluding each other.

What is resource partitioning?

Resource partitioning is when species evolve to use different parts of a resource, reducing direct competition and allowing species to coexist.

What is character displacement?

Character displacement is when species evolve physical traits that reduce competition by differentiating how they exploit resources.

What is intraspecific competition’s effect?

Intraspecific competition leads to social hierarchies, where dominant individuals control resources and submissive individuals are excluded from certain resources.

What is territoriality?

Territoriality is the defense of an area by an individual or group to protect access to resources, often seen in intraspecific competition.

What is symbiosis?

Symbiosis refers to a close, long-term relationship between two species, which can be mutualistic, commensal, or parasitic.

What is mutualism?

Mutualism is a symbiotic relationship in which both species benefit, such as hummingbirds pollinating flowers while obtaining nectar.

What is commensalism?

Commensalism is a symbiotic relationship in which one species benefits and the other is neither helped nor harmed, such as barnacles living on whales.

What is parasitism?

Parasitism is a symbiotic relationship in which one species benefits at the expense of the other, such as lice feeding on humans.

What is ectoparasitism?

Ectoparasitism occurs when parasites live on the exterior of their host, such as lice on the skin of mammals.

What is endoparasitism?

Endoparasitism occurs when parasites live inside their host, such as tapeworms in the intestines of their host.

What is a vector in parasitism?

A vector is an organism that transmits a parasite or disease, such as mosquitoes carrying the malaria parasite.

How do parasites harm their hosts?

Parasites harm their hosts by eating host tissue, secreting toxins, and consuming food from inside the host.

What is population regulation?

Population regulation is the process by which species interactions (like predation, competition, and parasitism) help control population sizes and maintain ecosystem balance.

What are examples of parasitic diseases in humans?

Parasitic diseases in humans include athlete’s foot, ringworm, yeast infections, and malaria.

How do parasites affect their hosts?

Parasites can affect their hosts by causing tissue damage, secreting toxins, and draining nutrients, all of which can reduce the host's fitness.

What is the role of predation in population control?

Predation helps regulate prey populations, preventing overpopulation and maintaining food reserves in the ecosystem.

What is the significance of competition in ecosystems?

Competition helps regulate population sizes by ensuring that resources are distributed efficiently and preventing any one species from dominating the ecosystem.

What is the significance of symbiotic relationships?

Symbiotic relationships, such as mutualism, commensalism, and parasitism, are critical for maintaining biodiversity and ecosystem stability.