Ecology Study Guide
1. Define ecology. Study of the interactions between the organisms and their environment
2. Explain how CFCs cause a problem in our environment. they deplete the amount of ozone in the atmosphere which
allows more harmful ultraviolet radiation to reach Earth’s surface
3. T/F. Increasing CO2 which traps more heat, causes temperatures on Earth to increase. T
4. Define population. Organisms of the same species in the same area at the same time
5. Define habitat. Everything an organism needs to survive
6. Define an organism’s niche. Way of life for an organism; includes mating, feeding, transportation, diurnal vs
nocturnal, annual rhythms
7. What are some factors that can determine if a population will grow or decrease in size? Availability of food, water,
space, mates
8. What type of growth is being illustrated in each graph below?
Carrying
Capacity
Exponential
Growth
9. What would happen if a population is on its way to reaching its carrying capacity? There would be an increased rate
of death of individuals in the population
*Write which symbiotic relationship each question below is representing.*
(parasitism, mutualism, competition, commensalism, mimicry)
10. The ant keeps predators away from the acacia tree and the acacia tree provides shelter and food for the ant.
_mutualism_______________
11. If a cow eats the grass and a sheep eats the same grass. What will this cause between the two organisms?
___competition_____________
12. The tree provides nutrients and a sunlit location or the orchid living on it. ____parasitism____________
13. The dog provides nutrients and shelter for the tapeworm living in its intestines. ___parasitism________
14. Both organisms benefit from the activity of each other. __mutualism_______________
15. One organism benefits, and the other organism neither benefits nor suffers harm. _commensalism_______
16. One organism obtains its nutrients from another, and the other organism may weaken due to deprivation.
__parasitism___________________
17. Plants and bees that pollinate them. ____mutualism_____________
18. Whales and the barnacles growing on its skin. __commensalism_________________
* Fill in the diagram below. After filling in the appropriate trophic levels, explain how the energy flows through
the ecosystem.*
Tertiary Consumer – 0.1%
Secondary Consumer – 1%
Primary Consumer – 10%
Producer -100%
As energy moves up the trophic levels
only 10% is available to the next higher
level. As a result, there have to be many
more producers than tertiary consumers
19. Explain the process of the nitrogen cycle by answering the following questions: What is the atmospheric form of
nitrogen? What does bacteria convert the atmospheric form of nitrogen to before it reaches nitrates? What is the
usable form of nitrogen in plants? What are the products of the nitrogen cycle?
N2, ammonia (NH4), nitrate (NO3),
20. Explain how humans are affecting the carbon cycle.
Humans are adding carbon in the form of carbon dioxide (CO2) to the environment faster that it can be removed
which contributes to global warming
21. Explain the difference between a food web and a food chain. A food chain only looks at predator-prey
relationships with one set of organisms in a habitat. A food web looks at the relationships of all organisms within
a habitat.
22. What is the difference between density-independent and density-dependent limiting factors? List 2 examples of
each factor. Density-independent limiting factors are things like floods, fires and weather that reduce a
population by the same proportion regardless of population size. Density-dependent limiting factors are things
like loss of habitat or reduction in food supply that reduce a population; linked to an increase in population.
23. Explain the predator-prey relationship. as the number of prey increase, the number of predators increase until the
food source for the prey starts to diminish (due to a large population) and the number of prey start to die off; this
in turn causes the number of predators to decrease due to decrease in prey; with a decrease in prey, the prey’s
food source starts to increase and the cycle starts again
24. What are the levels of classification from most general to most specific? Kingdom, phylum, class, order, family,
genus, species
25. Who is responsible for the binomial nomenclature? Carolus Linnaeus
26. Define taxonomy. Science of grouping and naming organisms based on natural relationships
27. Humans
a. scientific name – _Homo sapiens_______
b. genus – ___Homo_______________
c. species – _____sapiens____________
28. Define phylogeny. Evolutionary history of an organism
29. Explain the difference between phylogenetic tree and cladogram. A phylogenetic tree shows the evolutionary
past of organisms where the base of the tree is a common ancestor; A cladogram is a diagram showing
relationship between animals
30. Give a description of each kingdom below. (prokaryotic/eukaryotic, unicellular/multicellular,
autotroph/heterotroph, asexual reproduction/sexual reproduction)
a. Kingdom Archaebacteria and Eubacteria – prokaryotic, unicellular, autotrophic or heterotrophic, asexual
reproduction
b. Kingdom Protista – eukaryotic, mostly unicellular, autotrophic or heterotrophic, asexual reproduction
c. Kingdom Fungi – eukaryotic, unicellular or multicellular, heterotrophic (external digestion), mostly
asexual reproduction
d. Kingdom Plantae – eukaryotic, multicellular, autotrophic, sexual and asexual reproduction
e. Kingdom Animalia – eukaryotic, multicellular, heterotrophic (internal digestion), sexual reprodution
31. List the four organic molecules along with their function and building block.
Lipids – fatty acids
proteins – amino acids
nucleic acids - nucleotides
Carbohydrates –monosaccharides, disaccharides, polysaccharides
32. What is the function of enzymes? Speed up chemical reactions by lowering activation energy; substrate specific
and can be reused
33. Explain the difference between active and passive transport. Active transport requires the expenditure of energy
(ATP) to move substances across a plasma membrane where passive transport does not
34. What is ATP? Adenosine triphosphate; the energy molecule of organisms
35. List the function of the following organelles:
a. Ribosome – site of protein synthesis
b. Chloroplast – site of photosynthesis; found only in plants
c. Mitochondria – site of cellular respiration (powerhouse of the cell); found only in animals
d. Cell membrane – found only in animals; regulates what passes into and out of a cell
e. Cell wall – found only in plants; provides structure and shape
36. Explain cellular respiration and photosynthesis. Cellular respiration occurs only in animals cells and is the
process where oxygen and sugar combine to produce carbon dioxide and water: O2 + C6H12O6
CO2 +H2O
Photosynthesis occurs only in plants and is the process where carbon dioxide and water combine to produce
oxygen and sugar: CO2 + H2O
O2 + C6H12O6
37. If a saltwater plant was place in a freshwater solution, what would happen to the saltwater plant? it would swell
and eventually burst
38. Replicate: TAG GTA GGT ATC CAT CCA
(DNA to DNA)
39. Transcribe: TAG CAG AAT AUC GUC UUA (DNA to RNA)
40. Translate: AUG UAC GAC
Met Tyr Asp
41. What is the difference between mitosis and meiosis? Mitosis is asexual reproduction that results in 2 identical
diploid daughter cells; meiosis is sexual reproduction that results in 4 haploid cells
42. Explain the difference between incomplete dominance and codominance. With dominance one trait is expressed
over all others (ex. Curly hair over straight hair); with codominance both traits are expressed (a brown cow and
white cow mate to produce brown and white offspring)
43. Know your punnet square problems. (normal, blood type-multiple allele, sex-linked: always recessive)
44. Define natural selection. Organisms best suited to their environment reproduce more successfully than other
organisms
45. Define homologous structures. Similar features that originated in a common/shared ancestor
46. Distinguish between stabilizing, directional and disruptive natural selection.
Stabilizing selection – individuals with the AVERAGE trait have the highest fitness
Directional selection – individuals ONE EXTREME or the other of a trait have the highest fitness
Disruptive selection – individuals with EITHER EXTREME of a trait have the highest fitness