Unit 4 - Populations Exam Review

What is coevolution? Give an example.
When 2 species evolve in response to a relationship with each other. A moth and an orchid.
How are population density and dispersion different?
Density is the concentration in a given area, dispersion is the arrangement of individuals.
What are the three types of symbiotic relationships?
Commensalism, Mutualism, Parasitism
Define commensalism and give an example.
When one organism benefits and the other is neither harmed nor benefits. Whale and barnacles.
Define mutualism and give an example.
When both organisms benefit. Suckerfish and shark.
Define parasitism and give an example.
When one organism benefits and the other is harmed. Flea and dog.
Define predation and give an example.
When one organism hunts/eats another. Lion and Zebra.
Define competition and give an example.
When two organisms/species attempt to use the same limited resources. A forest full of trees competing for space, water, nutrients, and sunlight.
Describe how a population's growth could be zero.
1- birth rates = death rates. 2- when each couple has 2 kids to replace themselves.
What is carrying capacity? What determines it?
The maximum population an ecosystem can support indefinitely. Limited resources.
What is a population?
All members of a species in the same area.
How have humans caused extinction events?
Habitat destruction, pollution, poaching, introducing invasive/exotic species, etc.
What is happening to the current rate of extinction?
It is rapidly increasing.
What is a population pyramid?
A graph of the distribution of ages and sexes in a population.
What are ways that world birthrates can be lowered?
Educating women, family planning techniques, access to contraception, etc.
When did human population grow the fastest?
Modern age/Industrial revolution.
When will human population stabilize?
What will the human population be when it stabilizes?
9 Billion
How would prey respond to the exponential growth of a predator?
The prey population would decrease, possibly disappearing from that ecosystem.
What would the shape of a population pyramid for a country with rapid growth be?
Like a steep pyramid or volcano with a wide base and narrow top
Why do developing countries have more rapid population growth?
Poor infrastructure, poor family planning, inadequate contraception, poor view of women, etc.
What is a demographer?
A person who studies human populations.
Define endangered species.
A species that is in danger of becoming extinct.
Define threatened species.
A species that could become endangered if something doesn't change.
What is biodiversity?
Biological diversity. The number of different species and amount of individuals in the different species in an area.
What is the Endangered Species Act?
An act passed by the US Congress in 1973 to protect endangered animals and plants. It imposes fines for poaching.
Why is biodiversity important?
Many reasons. 1- Diversity in a population allows populations to adapt to changing environments. 2- Humans rely upon various species for food, clothing, shelter, medicines, etc. 3- EVERY species plays a part in its ecosystem and food web.
What is niche?
The role of a species in its habitat.
What is infrastructure?
The basic facilities of a country/region, such as; roads, sewers, and bridges.
What is a gene?
A section of DNA that codes for specific traits in living organisms.
What is a keystone species?
A species that is very important to the success and survival of its ecosystem.
How have countries tried to address population growth?
China - Developed a 1 child policy, worked well... maybe too well. Led to an imbalance in females and males.
India - Developed a Family Planning Program that did not work very well, and led to an imbalance in females and males.