For the last part of the biology unit, I'm putting in questions from the unit review.
3. a) this biome has a permafrost, a short growing season, and no trees: tundra
f) the main vegetation in the biome is coniferous trees: boreal forest
7. Identify each of the following biotic interactions
a) An ant species feeds on the sweet tasting chemicals produced by a caterpillar species. The ants vigorously protect the caterpillars and carry them to their nests at night for safety. This is an example of mutualism.
c) A whip worm lives in the large intestine of a dog and causes the dog to lose mass. This is an example of parasitism
d) A salamander uses it's sticky tongue to capture an insect. This is an example of predation.
9. Using an example of each, compare and contrast the diets of detrivores omnivores, and herbivores.
Detrivores, such as worms, only eat dead organic matter eating at every trophic level. Omnivores, such as bears, eat both plants and meat. Herbivores, such as deer, only eat plants.
14. How do persistent organic pollutants such as DDT affect organisms?
Persistent organic pollutants (POPs) have a long half-life and bioaccumulate in plants, then in fatty tissues of animals. They can also wash into streams and lakes, affecting the aquatic food chain. DDT can cause nervous system, immune system, and reproductive disorders.
16. Describe the harmful effects on humans of bioaccumulations of the following:
a) Lead: lead can cause anemia, nervous system damage, low fertility rates, impaired mental development, and kidney failure.
b) Cadmium: cadmium can cause infertility and damage to the central nervous system, immune system, and DNA
c) Mercury: mercury can cause damage to the nerve cells, the heart, the kidneys, the lungs, and suppresses the immune system.
18. List two abiotic factor the influence ecological succession.
Soil, and water
19. Explain how primary succession differs from secondary succession.
Primary succession occurs on an area where no living things are, where there's bare rock. Secondary succession occurs where there once was living things.
These questions show my understanding from all three chapters of the biology unit.
Sunday 27 November 2011
Biology #2
PCBs and the Orcas
From the 1930s to the 1970s PCBs or polychlorinated biphenyls were used in industrial products. In 1977 they were banned in North America as concerns about what the PCBs were doing to the environment were growing. But synthetic chemicals, such as PCBs, bioaccumulate, biomagnify, and have a long half-life. PCBs stay in organisms, suppress the immune system, and may cause cancer in humans. But aquatic ecosystems have taken a hard hit with the PCBs
The animal that was hit the hardest was the orcas. A study found that PCBs will interfere with the orcas reproductive system until at least 2030. Though the chemicals have been banned for decades, the orcas retain high levels of PCBs, especially the calves. The figure shows how biomagnification occurs in orcas. PCBs enter the food chain at a low level in the microscopic plants and algae, but by the time the PCBs reach the orca, they are highly concentrated in the blubber. When the salmon population gets low, magnification is increased, since blubber is burned for energy. The PCBs are then released into the bloodstream where they interfere with the immune function, making the orca more susceptible to disease.
Not only does this show my knowledge of half-lives, which relates back to the chemistry unit, it also shows how pollutants climb up the food chain, as well as bioaccumulation and biomagnification.
From the 1930s to the 1970s PCBs or polychlorinated biphenyls were used in industrial products. In 1977 they were banned in North America as concerns about what the PCBs were doing to the environment were growing. But synthetic chemicals, such as PCBs, bioaccumulate, biomagnify, and have a long half-life. PCBs stay in organisms, suppress the immune system, and may cause cancer in humans. But aquatic ecosystems have taken a hard hit with the PCBs
The animal that was hit the hardest was the orcas. A study found that PCBs will interfere with the orcas reproductive system until at least 2030. Though the chemicals have been banned for decades, the orcas retain high levels of PCBs, especially the calves. The figure shows how biomagnification occurs in orcas. PCBs enter the food chain at a low level in the microscopic plants and algae, but by the time the PCBs reach the orca, they are highly concentrated in the blubber. When the salmon population gets low, magnification is increased, since blubber is burned for energy. The PCBs are then released into the bloodstream where they interfere with the immune function, making the orca more susceptible to disease.Not only does this show my knowledge of half-lives, which relates back to the chemistry unit, it also shows how pollutants climb up the food chain, as well as bioaccumulation and biomagnification.
Biology #1
This is a picture of the nitrogen cycle. Nitrogen is an important component of DNA and proteins. It is also essential for muscle function and growth.
This shows the many different stages of the nitrogen cycle, including nitrogen fixation, nitrification, uptake, and denitrification. The picture also shows where nitrogen is stored, the atmosphere, as well as the different ions that nitrogen is changed into.
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