Ecology test study Flashcards
What is a population? What is a community? What is an ecosystem?
A population is many of the same species living in an area together
A community is many different populations (different species) living in an area together
An ecosystem includes the community and all of the non-living physical features such as water and soil
What causes a population to increase in size?
Unlimited access to resources (food or space), lack of predators, immigration or increased birth rate
What causes a population to decrease in size?
Increase in predators, limited access to resources (food or space), emigration or increased death rate, disease, natural disasters (flood or fire)
What is a habitat?
The specific environment where an organism lives
What is the difference between biotic and abiotic factors?
Abiotic factors are not living, biotic factors are living or were once living
What is a niche?
The role an organism plays in a community
What are the different biomes (and their characteristics)?
Desert (driest with large ranges in temperature between day and night)
Temperature forest (has precipitation spread evenly throughout the year and experiences seasonal changes)
Tropical rainforest (has year-round warm temperatures and lots of rain)
Aquatic (freshwater or marine - in bodies of water)
Tundra (occurs in high latitudes with a cold and dry climate)
Taiga (in between temperate forests and tundra)
Savanna (tropical and dry, grasslands)
What is the difference between gestation and generation time?
Gestation time is how long it takes for a embryo or fetus to be born and generation time is how long until an individual is able to reproduce themselves
How does age distribution in a population affect a species?
Depending on the generation time, the age of the population could affect the birth rate, if a population only has really young or really old members, the birth rate could fall and the population could decrease in size
What is carrying capacity and how can you identify it on a graph?
The largest population that can be supported and sustained by and in a specific environment
On a graph, look for where the population levels off
What can affect the carrying capacity of a population?
Number of predators or prey, availability of resources, competition, weather and natural disasters
What are the three types of survivorship curves?
Type 1 - organisms that usually give birth to one offspring at a time
Type 2 - organisms that have a 50/50 shot of survival
Type 3 - organisms that are likely to be eaten as eggs
What is a keystone species?
An organism that plays a large role in its community and if removed would affect the community structure significantly
How might an organism adapt to its environment to keep from being eaten?
Camouflage, conceal itself from a predator by blending in with the environment
What are the ways species can interact with each other?
Herbivory - when an animal eats a plant
Predation - when an animal kills and eats another animal
Competition - when animals of the same or different species use the same resources
Mutualism - when two species interact and they both benefit
Commensalism - when two species interact, one benefits and the other is unaffected
Parasitism - when two species interact, one benefits and the other is harmed
On a food web, what do the arrows show?
Where the energy is going, the arrow should point to what is eating
What is the difference between producers and consumers?
Producers make their own food (photosynthesis or chemosynthesis) and consumers rely on other organism for their energy
How do you identify what trophic level an animal is in a food web?
A primary consumer eats a producer. A secondary consumer eats a primary consumer. A tertiary consumer eats a secondary consumer. Count how far away from the producer.
What is the difference between carnivores, omnivores, and herbivores?
Carnivores - eat meat, herbivores - eat plants, omnivores - eat both
What is a decomposer?
Decomposers and detritivores break down or consume dead material to make it usable for the producers again
What is the difference between biodiversity and a monoculture?
Biodiversity means there is a variety of plant and animal species in an area, monoculture means there is one single plant species growing in an area (often found in agriculture)
How do we measure biodiversity?
Species richness (the number of different species present) and species evenness (the relative abundance of different species - how the number of individuals of different species compares to each other)
What are ecosystem services or benefits of biodiversity?
Purification of air and water, pest control, provides food and fuel, development of medicines, decomposition of waste, income of local economies, agriculture, increased stability in the ecosystem
What are the main causes of biodiversity loss?
Habitat change and loss (the leading cause globally), invasive species, pollution, overharvesting, climate change
What are the consequences of biodiversity loss?
Extinction - when the last individual of a species dies out, Endangered - a species at risk of extinction, Extirpation - the disappearance of a particular population from a given area, but not of the entire species globally
What is the difference between primary and secondary ecological succession?
Primary succession begins from rock, then lichen and moss and pioneer species start to break down the rock, once soil begins to form, small insects and plants move in, over time, larger plants and trees establish themselves and more vegetation grows, Secondary successions begins from preexisting soil, plants that were already present begin to grow first and then eventually more vegetation is introduced
What is a pioneer species?
The first species to populate in an area during primary succession
What is the order of ecological succession?
1) The retreating glacier leaves behind bare gravel with no soil.
2) Moss beginning to break down a rock.
3) Dwarf fireweed, a pioneer species.
4) Alder (left) and willow (right) growing in the wake of the retreating glacier.
5) A cottonwood-dominated forest.
6) A spruce tree growing in a stand of cottonwoods
What is carrying Capacity?
largest population size a given environment can sustainably support.
