Name: ___________________________
Block: _______ Date: _______________
Unit 4: Populations
Study Guide
Notes #1: Populations Change in Size
1. What is a population?
a group of organisms of the same species that live in a specific geographical area
and interbreed.
2. What is growth rate?
an expression of the increase in the size of an organism or population over a
given period of time. It is the birth rate minus the death rate.
3. What is exponential growth?
logarithmic growth or growth in which numbers increase by a certain factor in
each successive time period.
4. What is carrying capacity?
the largest population that an environment can support at any given time.
5. What is a limiting resource?
A natural resource that determines carrying capacity of an ecosystem or species.
6. How can a resource be density dependent?
deaths occur more quickly in a crowded population than in a sparse population.
7. How can a resource be density independent?
Deaths occur regardless of the density of the population
Notes #2: Populations Change in Size
8. What is the formula for growth rate?
b(birthrate) – d(deathrate)
9. What is doubling time?
The amount of time it takes for a population to double
10. What does emigration mean?
someone leaving an area
11. What does immigration mean?
Someone coming into an area
12. What is the formula to tell if growth occurs?
# of births + # of immigrants > # deaths + # of emigrants
13. What is birth rate?
# of births per 1000 people
14. What is death rate?
# of deaths per 1000 people
Notes #3: Species Interactions
15. What is a habitat?
actual place where an organism lives
16. What is a niche?
the way of life for an organism; the “job” an organism performs in an ecosystem
17. What is predation? What are the two organisms called?
one organism kills and eats another organism. prey: organism being eaten
predator: organism doing the eating
Name: ___________________________
Block: _______ Date: _______________
18. What is competition?
when two organisms attempt to use the same limited resources
19. What are the two type of competition and describe how they are different.
a) Intra-specific Competition: competition
between individuals of the same species
Ex. Lions fighting for food.
a) Inter-specific Competition: competition
between two different species
Ex. Lions and hyenas fighting for food
20. What is parasitism? What are the two organisms called?
symbiotic relationship where one organism feeds on the tissues or body fluids of
another
a) Parasite: organism that live in or on another organism without
immediately killing it
Ex. Ticks, fleas, leeches, heartworms
a) Host: organism the parasite gets its nourishment from Ex. Human, dog
21. What are the two major ways that parasitism and predation differ?
1. Parasites don’t immediately kill hosts
2. Parasites live on or in host for a part of its life.
22. What does symbiosis mean?
2 species live closely together
23. What is mutualism?
symbiotic relationship where all species benefit
24. What is commensalism?
symbiotic relationship where one species benefits and the other is neither helped
nor harmed.
25. What is predator capacity?
the maximum number of predators a prey population can support
Notes #4: Biodiversity
26. What is biodiversity?
Usually refers to the number of different species in a given area
27. What is species diversity?
the number of different species in an area
28. What is ecosystem diversity?
the variety of habitats and communities between ecosystems
29. What is genetic diversity?
examine the number of different genes within one population
30. Why is biodiversity important?
can affect the stability of ecosystems and the sustainability of populations, We
depend on healthy ecosystems to ensure a healthy biosphere that has balanced
cycles of energy and nutrients, Species are part of these cycles.
31. What is an endangered species?
a species that is likely to become extinct if protective measures are not taken
immediately
Name: ___________________________
Block: _______ Date: _______________
32. What is a threatened species?
a species that has a declining population and that is likely to become endangered
if it is not protected
33. What is a keystone species?
a species that is critical to the functioning of the ecosystem in which it lives
because it affects the survival and abundance of many other species in its
community.
34. What is an exotic species?
species that is not native to a particular region.
35. What is a extinct species?
A species of which every last individual has dies
36. What is a biodiversity hotspot?
Critical ecosystem with a high species diversity
37. List the four ways that humans can cause a species to become extinct.
1. Habitat destruction & fragmentation
2. Invasive Species
3. Pollution
4. Harvesting, Hunting, and Poaching
38. List the five things that humans can do to save species.
1. Captive breeding
2. Preserve genetic material
3. Gardens
4. Zoos
5. Aquariums
6. Parks