Download Chapter 5 Study Guide –KEY

Chapter 5 Study Guide –KEY
Pages 82-102
1. Distinguish Abiotic from Biotic Factors (give examples from the Marine Headlands)
factors in an environment,
Abiotic factors are nonliving factors while Biotic factors are living factors in an ecosystem.
Examples:
Abiotic: any of the environmental conditions such as temperature, windspped, tide, cloud cover, salinity etc.
Biotic: mole crabs and sea lions
What are limiting factors?
The factors that limits the population growth of species. Examples: temperature, wave action, light, a nutrient.
What is a Range of Tolerance?
The range of environmental conditions organisms living in an environment can tolerate. For example,
organisms can only tolerate a certain range of temperatures.
2. Distinguish a species’ niche different from its habitat?
Habitat is where an organism lives while niche is the organism’s role in its surroundings.
Niche = habitat + habits
3. What is the competitive exclusion principle? Give an example from marine biology.
It’s the theory that states that no two species can occupy the same niche and compete for the same resources in
the habitat for a very long time.
Example: A classic example from marine biology is the competition between barnacle species on a rocky shore.
4. What is natural selection?
Natural selection is reproductive survival of the fittest in a particular environment. The environment selects or
determines which individuals out-reproduce others because of their traits. . The organisms with the fittest genes
will have the highest chances of survival and therefore their genes will be passed on.
Why is natural selection the driving force of evolution?
It can account for adaptations and the direction of evolutionary change. Mutation and genetic drift cannot.
Distinguish individual selection from group or species-level selection. (ask me in class).
Group selection benefits the species at the expense of the individual. It is unlikely to be a strong effect on the
evolution of traits, because reproductive selfishness by individuals will be more successful in passing on genes.
Selfish lemmings will leave more descendents.
Elephant seal males selfishly kill pups (probably not their one), but pass on their genes by increasing mating
success.
Cute baby piglets have nasty sharp teeth they use to fight their siblings for the best teats. The weakest piglets
can die.
5. Describe step-by-step how pesticide resistance evolves in a pest organism like the corn-borer beetle by
individual selection. (see Figure 5.6) on page 85.
1) There is variation in the genes of the beetle, so some beetles are resistant to the pesticide and the
2) Genes of the resistant beetles are passed on more often than genes of pesticide-sensitive beetles.
3) After couple generations, the beetles that are not resistant to the pesticides will be eliminated while the
resistant beetles remain.
(Variation –Inheritance-Differences in Reproductive Success)
6. Distinguish extinction from mass extinction?
Extinction is the total elimination of one species while mass extinctions is extinction of a large percentage of
the earth’s species.
How does the recent rate of extinction compare to background extinction rates?
The recent rate is about 50X as high as the background rate. The rate of extinction is correlated with the
increase in human population.
Causes (MEMORIZE HIPPO)
H= Habitat loss (#1 cause for mst species)
I = Invasive species (an increasing problems)
P = PollutioP = Population increase, and increased needs of people
O = overexploitation (over-fishing, over-hunting, etc)
7. Describe these relationships and give an example of each: How do they apply to the human niche? (p.89-90)
predator-prey :an organisms eats another organism for food (win/lose)
humans: humans slaughter other animals for food
parasite-host: the parasite attaches itself to the host then exploits it (win/lose)
humans: Some people in Africa draw cow blood for food. Also the Mongols and other nomadic
tribes.
competition (intraspecific): Competition for same resources between same species (lose,lose)
humans: Human compete with each other for more land for resources
competition (interspecific): Competition for same resources between different species (lose,lose)
humans: insects compete for our food crops, sometimes mice and fungi, too.
mutualism: a long lasting relationship between two organisms where both organisms benefit
humans: our domestic crops and animals, honeybees, honey guides (birds that lead people to
bees nests. Birds eat wax, humans get honey). (win/win)
commensalism: a long lasting relationship between two organisms where one side benefits while one
side neither loses nor gains anything (win/no effect)
humans: mites in our hair follicles
OTHER EXAMPLES ARE POSSIBLE
8. Distinguish Community from Ecosystem:
Community is interacting group of different species while ecosystem is a interacting group of different species
along with their physical environment.
9. Describe the roles of: Give an example for each from the Marin Headlands
Producer-organisms that are able to make their own food, through processes like photosynthesis and
chemosynthesis. Ex: phytoplankton
Herbivore- Organisms that are vegetarians. Ex: deer, manatees and dugongs
Omnivore – organisms that eats both plants and animals. Ex: sand crabs (mostly eat phytoplankton)
Scavenger – organism that eat dead thing. Ex: the small critters that eats left over of dead animals on
beach
Parasite – an organism that lives in a host. Ex: roundworms in sea lions’ lungs
Decomposer – organisms that that use nonliving organic matter as a source of energy and raw materials
to build their bodies. Ex: Fungi in the shady areas in Marin Headlands, bacteria, invertebrates (FBI)
10. Energy flows 1-way through an ecosystem. Why? Useful energy is lost (in form of heat or disorganization)
whenever energy is transformed from one kind or place to another. This means it can’t all be recycled. New
input of energy is needed all the time.
Which LAW says you can’t recycle energy? The 2nd Law of Thermodynamics (Entropy (heat and
disorganization) is always increasing overall.
11. What is a food chain
A food chain is a passage of energy from one trophic level to the next as a result of one organism consuming
another.
? Which way to the arrows go and why? Arrows point up in the food chain (from food organism to consuming
organism) indicating where the energy goes.
12. What is a food web?
A food web is a diagram that shows the kinds of feeding interactions that take place in a community.
What does it show? It shows the predator and prey relationships between organisms in the community.
13. How do you determine the Trophic Level of an organism in a food chain?
Just count the links in the food chain leading to that organism. The producers count as one. An organism may
occupy more than one level.
14. What is a Habitat Conservation Plan?
The Habitat Conservation Plan is an agreement between stakeholders (people with different interests) about
land use. It includes compromises between total protection and total conversion of animal habitats to human
use.
Why might it be considered a token? (p.83): It might be considered a token if it appears to address
environmental concerns but serves as a means of ignoring them.
15. What is an exotic species?
An exotic species is a species that lives outside its native range of community
What emerging infectious diseases originate in animals? (p. 90)
Monkeypox was brought into the U.S. from the exotic species. The SARS virus originated in wild masked palm
civets.
16. How did heavy metals and organic molecules end up in the Great lakes? (p. 95)
Industrialization brought in a lot of metals and organic molecules. Many companies disposed metals in the
Great Lakes has a lot of metals and organic molecules because it was a cheap way to get rid of the metal and
organic waste.
Why do they accumulate in animals’ bodies (bioacculumation)?
Living things have not evolved the physiology to break down and eliminate some toxins. If they take them in in
their food, the toxins just accumulate in their bodies (= bioaccumulation).
and concentrate in higher levels of the food chain (biomagnification)?
Little organisms like plankton and fishes mistaken them as food and ate them. Larger fishes then ate the smaller
fishes. The larger fishes have to eat lots of small fishes, so the metal and organic molecules get built up as the
trophic level in the food chain goes up.
___84___% of fish in Great Lakes tributaries have cancer.
Approximately __500_____ different organic molecules have been found in the bodies of fish from the Great
Lakes.
Why can’t the fish all be tested for these contaminants?
Because it’s expensive, it cost thousands of dollars and there are lots of fishes.
How do these steps reduce a human’s exposure to carcinogens in fish:
1. Don’t eat bottom-feeding species. MANY TOXINS SINK TO THE BOTTOM
2. Eat little fish not big fish. OLDER, LARGER , HIGHER TROPHIC LEVEL FISH WILL HAVE
ACCUMULATED MORE TOXINS BECAUSE OF BIOMAGNIFICATION.
3. Remove and avoid the fat. SOME TOXINS ARE FAT SOLUBLE AND CONCENTRATE IN THE
FAT AND OIL OF A FISH
4. Don’t consume a lot of fish. None if a child or pregnant mother. FETUSES AND CHILDREN ARE
MORE VULNERABLE.
Due by Friday 10/26 in hard copy.
17. – 20. Elements needed for living things (nutrients) can be recycled. Make a detailed sketch and describe
briefly these chemical cycles (C, N, P):
a) State why each element is important for living things.
b) Give the time scale of cycling.
c) Identify important sinks and the processes by which the nutrient moves from one sink to another.
d) Indicate greenhouse gases produced in each cycle.
e) Indicate human impacts on each cycle.
**Which is most often discussed in relation to global warming?
Include in your sketches:
CARBON: (p. 96 and colorsheet back). Indicate greenhouse gases.
NITROGEN (p. 98 and colorsheet back))
Note roles of bacteria: Nitrobacter, Nitros ammonas and Rhyzobium sp.
Match with their important activities: nitrogen fixation, and denitrification.
How have humans interfered with the nitrogen cycle? What problems can occur?
PHOSPHORUS (p.99 and colorsheet back) – How humans have influenced the movement of phosphorous in
the biosphere. Environmental problems caused by excess phosphorus. (See box essay p. 101)