Math
1200 kw = ? MW (megawatts)
1200 kw = 1.2 MW
Students are designing an experiment to test the effect of salinity on seed germination. Germination is the sprouting of a seedling from a seed.
The students set up 4 petri dishes with 3 seeds and apply either water or a salt solution: 0%, 1.5%, 2.25%, or 3% salt. All of the samples will receive the same amount of liquid, be exposed to the same amount of sunlight and will be observed for the same number of days.
What's the independent variable?
Concentration (%) of salt in the solution
Tree-dwelling and ground-dwelling mammals occupy different vertical zones within a forest, utilizing different nesting sites.
What is occurring?
spatial resource partitioning
Peat formation arises from decomposition of ____________, then which two abiotic factors cause it to turn into coal?
decomp. of plant material
heat & pressure
60 grams = ??? milligrams
60 grams = ___6,000 milligrams_
If cyanide in a stream next to a gold mine increases from 240 ppm to 360 ppm, what percent increase is this?
Percent increase = (New value - Original value) / Original value * 100
Percent increase = (360 ppm - 240 ppm) / 240 ppm * 100
= 120 ppm / 240 ppm * 100 = 0.5 * 100 = 50%
The cyanide concentration in the stream increased by 50%.
Students are designing an experiment to test the effect of carbon dioxide bubbled into aquarium tanks filled with aquatic plants. The students believe more carbon dioxide may increase primary productivity.
The students set up 4 tanks and add varying amounts of carbon dioxide. At the end of the experiment, they plan to measure the change in mass of the aquatic plants.
What's the dependent variable?
Change in mass of the aquatic plants
In a newly formed pond, pioneer species such as algae and floating plants colonize the water. Over time, as organic matter accumulates and sediment builds up, emergent plants like cattails and reeds establish themselves at the pond's edges, eventually transforming the pond into a marsh or wetland.
Primary succession because life is colonizing a newly created habitat & no life existed here previously.
Which primary pollutant is not present when ground level ozone forms, but does contribute to the formation of photochemical smog?
sulfur dioxide (SO2)
The LD50 for acetaminophen is 2404 mg/kg (rat, oral).
How many milligrams of acetaminophen would be the LD50 for a 60 kg (132 lb) adult?
LD50 (mg) = LD50 (mg/kg) × Body weight (kg)
LD50 (mg) = 2404 mg/kg × 60 kg
LD50 (mg) = 144,240 mg of acetaminophen for a 60 kg adult
If a city’s population doubles in 20 years, what is the growth rate?
Doubling time = 70 / Growth rate
20 years = 70 / Growth rate
Growth rate = 70 / 20
Growth rate = 3.5%
Therefore, if a city's population doubles in 20 years, the growth rate is 3.5% per year.
Students are designing an experiment to test the effect of salinity on seed germination. Germination is the sprouting of a seedling from a seed.
The students set up 4 petri dishes with 3 seeds and apply either water or a salt solution: 0%, 1.5%, 2.25%, or 3% salt. All of the samples will receive the same amount of liquid, be exposed to the same amount of sunlight and will be observed for the same number of days.
What's a good hypothesis for this experiment?
As salinity increases, the percent of seeds germinating will decrease.
Asian carp reach reproductive maturity within 4 years and females can lay over 1 million eggs per year. They are ___ - strategists and {are or are not} likely an invasive species.
r-strategists because of rapid reproduction & growth rate; YES, invasive
Atrazine is an herbicide used to control weeds in agriculture as well as suburban lawns. When it runs off into streams, studies have shown it can result in male frogs growing eggs in their testes.
Which type of water pollution is this & could it affect humans?
endocrine disruptor; yes-- can affect reproductive health
If 35% of a natural area is to be developed, leaving 520 acres untouched, how many acres are to be developed?
We know that 520 acres will be left untouched, and this represents 65% of the total area (100% - 35% = 65%).
Therefore, the total size of the natural area is:
520 acres / 0.65 = 800 acres
Since 35% of the 800 acres will be developed, the number of acres to be developed is:
800 acres * 0.35 = 280 acres
A 64g sample of Germanium-66 is left undisturbed for 12.5 hours. At the end of that period, only 2.0g remain. What is the half-life of this material?
Step 1: Recognize that after 1 half-life, half of the original amount remains.
After the first half-life, the remaining amount would be 64g / 2 = 32g.
Step 2: After 2 half-lives, half of the remaining amount from the first half-life remains, which is 1/4 of the original.
After the second half-life, the remaining amount would be 32g / 2 = 16g.
Step 3: Continue this pattern until the remaining amount is close to the given 2.0g.
After the third half-life, the remaining amount would be 16g / 2 = 8g.
After the fourth half-life, the remaining amount would be 8g / 2 = 4g.
After the fifth half-life, the remaining amount would be 4g / 2 = 2g, which is close to the given 2.0g.
Therefore, the half-life of Germanium-66 is approximately 12.5 hours / 5 half-lives = 2.5 hours.
Data for watershed study of a temperate deciduous forest in summer:
Location / Slope / Turbidity 100m downstream
A / 2% / 10 units
B / 8% / 15 units
C / 15% / 20 units
D / 0% / 8 units
Based on the information given about this watershed study, what is a constant or controlled variable?
Biome (temperate deciduous forest), time of year (summer)
A plate boundary is comprised of 2 continental plates with rift valley landforms, shallow earthquakes, and volcanic activity. Which type of boundary is this?
Divergent boundary
The measure of the reflectivity of a surface which impacts how much sunlight is reflected back into space and how much is absorbed as heat.
albedo
The net annual primary productivity of a particular wetland ecosystem is found to be 2,000 kcal/m2. If respiration by the aquatic producers is 18,000 kcal/m2 per year, what is the gross annual primary productivity for this ecosystem, in kcal/m2 per year?
Gross primary productivity is the amount of carbon fixed during photosynthesis by all producers in the ecosystem per unit area/per unit time.
GPP = NPP + Respiration
GPP = 2,000 kcal/m2 + 18,000 kcal/m2 = 20,000 kcal/m2 per year
The gross primary productivity of an ecosystem is 3.5 kgC/m2/year, and the energy needed by the producers for their own respiration is 3.0 kgC/m2/year. What is the net primary productivity of such an ecosystem?
The equation NPP = GPP - R shows that net primary productivity (NPP) is equal to gross primary productivity (GPP) minus the energy needed by the producers for their own respiration (R)
NPP = GPP - R
NPP = 3.5 kgC/m2/year - 3.0 kgC/m2/year
NPP = 0.5 kgC/m2/year
Data for watershed study of a temperate deciduous forest in summer:
Location / Slope / Turbidity 100m downstream
A / 2% / 10 units
B / 8% / 15 units
C / 15% / 20 units
D / 0% / 8 units
In this watershed study, what is the independent variable?
Slope
A single cow produces at least 150 pounds of methane, a potent greenhouse gas, as a byproduct of digestion each year. Collectively, cows are a significant source of a greenhouse gas which causes climate change.
Which type of meat production is this environmental problem most associated with AND what's a realistic solution?
CAFOs (concentrated animal feeding operations) or feedlots
eat a diet with less beef/meat; pasture-based/free-range systems; legislative changes to encourage more sustainable alternatives
The process by which certain gases in the Earth's atmosphere absorb infrared radiation leading to an increase in the temperature of the planet's surface and lower atmosphere.
greenhouse effect
Calculate the percentage growth rate for a country with a population of 5 million which has 100,000 births, 70,000 deaths, 30,000 immigrants, and 50,000 emigrants.
To calculate the percentage growth rate, we need to first find the total population change:
Total population change = Births - Deaths + Immigrants - Emigrants
= 100,000 - 70,000 + 30,000 - 50,000 = 10,000
The initial population is given as 5 million.
To calculate the percentage growth rate, we can use the formula:
Percentage growth rate = (Total population change / Initial population) x 100
= (10,000 / 5,000,000) x 100 = 0.2%
Therefore, the percentage growth rate for the country with a population of 5 million, 100,000 births, 70,000 deaths, 30,000 immigrants, and 50,000 emigrants is 0.2%.