Quiz 2: Biodiversity, Evolution & Ecology Flashcards
what is an example of a significant economic benefit from protecting biodiversity in rain forests and coral reefs?
production of chemicals to manufacture medicines
what are the two processes that determine the world’s current biodiversity
extinction and speciation
what is the most likely location of a biodiversity hotspot
islands
what term best describes the loss of a particular population from a given area (but not the entire species globally)
extirpation
European rabbits were introduced into Australia and quickly spread, reproduced, and became a terrible pest. They eat up to $600 million worth of food and pasture crops annually, and have damaged the populations of many native plants and the populations of animals that eat the plants. Twice in the past 50 years, rabbit diseases have been introduced to try to control the population, with some success. This is a case where an invasive species did what to the genetic diversity of the native species
reduced the genetic diversity of the native species
what is biodiversity
variety of all living things on Earth
What is something that is not true of endemic species
they are less susceptible to extinction than other species
what is the carrying capacity of a population
the population size that a habitat can support indefinitely with available resources
define minimum viable population
smallest number of individuals that allows the population to survive long term
what does the logistic growth model describe
population that grows rapidly at small numbers, but whose growth rate slows and eventually stops as it reaches the number that the environment can support
what is an example of a density dependent factor
ice storm causing damage to trees and shrubs
a single bacterium is put in an environment with no competition. as long as resources remain unlimited, how will the bacterial population respond
it will reproduce exponentially
when are populations expected to grow close to or at their intrinsic (or maximum) rate of growth
when their numbers are low
what is an example of a characteristic that is not required when describing a particular biome
size
what terrestrial biome has the highest diversity of species
tropical rainforest
what is the difference between a food chain and a food web
a food web shows interactions among all the species of a community instead of just a single line of energy transfer between single trophic levels
cattle egrets follow cattle around b/c cattle disturb insects as they walk, making the insects easier for the egrets catch. there is no cost or benefit to the cattle from this interaction. what type of interaction is involved?
commensalism
what does the concept of the trophic pyramid explain
each transfer of energy as you move up the food web results in a loss of about 90%
why is it important to learn how ecosystems function
-help humans and other species continue living and thriving on earth
-protect current ecosystems
-help restore already damaged ecosystems
-help scientists learn about complexities of biomes
what appears to be the cause of eutrophication that has taken place in the Gulf of St. Lawrence and other coastal locations around the world
excess nutrients from fertilizers
energy usually leaves an ecosystem in which form
heat
why is nitrogen often in short supply in terrestrial ecosystems
atmospheric nitrogen cannot be used by most organisms - needs to be converted to useful forms by bacteria and cyanobacteria
why are biogeochemical cycles crucial to ecosystem function
all chemical elements including nutrients are in limited supply and must be recycled
grain is eaten by cows and cows are eaten by humans. if the energy transfer between each trophic level is 10%, how much grain is required to produce 70kg of human biomass
7000kg
Biologists studying a population of birds observe that individual birds with average-sized wings survive severe storms better than those individual birds with either longer wings or shorter wings. Over time, the population is made up of more birds with average-sized wings. What term would apply to this situation?
stabilizing selection
what is an example of a human activity that has the potential to influence selection and affect evolution
use of pesticides, antibiotics, herbicides
Species are considered ______ when they face a high risk of extinction in the immediate future. Species are considered ________ when they are in danger of becoming _______ in the near future.
endangered; threatened; endangered
What term describes the intentional breeding for certain traits or combination of traits, commonly used in agriculture?
artificial selection
what is extinction
describes the disappearance of a species from Earth
in Earth’s history, there has/have been _______ major extinction event(s) leading to the loss of 50% or more of the species present
five
