Biosphere

Question 1

Ecotoxicology

Answer 1

the study of the ecological consequences of polluting the environment with various substances and radiation released by human activity.

Question 2

Contaminant

Answer 2

any type of substance or radiation that is likely to cause harm to one or more ecosystems.

Question 3

Types of contaminants:

Answer 3

a. The concentration (higher concentration=more toxic)

b. Type of organism it comes in contact with (contaminants are toxic to some organisms)

c. The length of exposure (longer exposed: risk of toxicity higher)

Question 4

Toxicity threshold

Answer 4

the level of concentration above which a contaminant causes one or more harmful effects in an organism.

Question 5

Lethal doses

Answer 5

LD50. Used to compare toxicity of contaminants and indicates the amount of contaminant necessary, in a single dose, to cause the death of an organism.

Question 6

Bioaccumulation

Answer 6

the gradual accumulation of substances, such as pesticides or other chemicals, in ONE organism.

Question 7

Biomagnification/bio amplification:

Answer 7

the rise or increase in the contaminated substances caused by the intoxicating environment. (Up the food chain).

Question 8

Biodegradation

Answer 8

(organic breaks down organic). It is the breaking down of organic matter into inorganic matter by microorganisms.

Question 9

Bioremediation

Answer 9

(bacteria eats toxins). It is a biotechnology for cleaning up a polluted site, using microorganisms that decompose the contaminants.

Question 10

Phytoremediation

Answer 10

(plants absorb toxins but store them inside). It is a biotechnology that uses plants or algae to eliminate contaminants from a site.

Question 11

Photosynthesis in carbon cycle

Answer 11

plants use solar energy to capture carbon dioxide found in the atmosphere or water.

Question 12

Ingestion in CC

Answer 12

to take carbon to grow, animals eat plants or other animals.

Question 13

Respiration in CC

Answer 13

carbon ingested returns to atmosphere as Carbon Dioxide.

Question 14

Forest fires in CC

Answer 14

release immense amount of carbon into the atmosphere

Question 15

Shells and skeletons in CC

Answer 15

CO2 in water reacts with molecules to form calcium to become calcium carbonate to form shells and skeletons. This also helps marine organisms.

Question 16

Carbonate rock in CC

Answer 16

shells and skeletons calcium carbonate form carbonate rock, which is subject to tectonic movement and can go back to surface.

Question 17

Volcanic eruptions in CC

Answer 17

releases CO2 (carbon goes back to atmosphere)

Question 18

Fossil fuels in CC

Answer 18

dead organisms fall to ocean floor and carbon changes into fossil fuels such as coal and oil. Takes hundreds of millions of years to process. (Releases CO2 into atmosphere.)

Question 19

Nitrogen cycle 5 steps

Answer 19

a. Nitrogen Fixation in NC: certain bacteria in the soil or water take the nitrogen from the atmosphere and converts into ammonia. Some of the ammonia reacts with hydrogen to form ammonium.

b. Nitrification in NC: bacteria oxidize ammonium to form nitrites. Other bacteria oxidize nitrites into nitrates.

c. Nitrogen Absorption by Plants and Animals in NC: plants can draw ammonium and nitrates from soil or water. Vegetation represents the only source of nitrogen available to herbivorous animals, which meet their need by eating plants. Meanwhile, carnivores obtain their nitrogen by eating herbivores or other animals.

d. Decomposition of Waste in NC: certain bacteria and fungi break down the nitrogen-containing substances in plant and animals waste (urine, dead organisms). They produce ammonia, which dissolves and forms ammonium.

e. Denitrification in NC: certain bacteria convert nitrates into molecular nitrogen, which returns to the atmosphere.

Question 20

Types of nitrogen

Answer 20

N, N2, NH3, NH4, NO2, NO3

Question 21

Erosion in PC

Answer 21

naturally occurring phosphorus is mostly in rocks. The wind and the rain slowly wear away small amounts of phosphorus from the rock, usually in the form of phosphates.

Question 22

Absorption by Living Organisms in PC:

Answer 22

plants can rapidly absorb the phosphates need for growth. Herbivores ingest phosphates by eating plants. Carnivores eat herbivores or other animals.

Question 23

Decomposition of Waste in PC:

Answer 23

digested phosphates are returned to the soil. All animals eliminate phosphates in their feces and urine. Phosphates are also released when decomposers break down dead plants and animals.

Question 24

Proliferation of Plankton and Sedimentation in PC:

Answer 24

phosphates from rocks or from animal and decomposed excretions make their way into the oceans. Some phosphates promote the growth of plankton (tiny marine organism that are the food of many larger life forms). Other phosphates sink to the bottom of the water and blend with the sediment. Very slowly, over millions of years, this mixture forms rock, returning to its original state.

Question 25

Tectonic uplift

Answer 25

A geologic process where the plates that make up the Earth’s crust crash into each other. This causes one plate to be pushed up by the other, heavier plate beneath it.