I think the most important level of the food pyramid is the fruit and vegetable group. Vegetables contain many vitamins and minerals; however, different vegetables contain different spreads, so it is important to eat a wide variety of types. Fruits are low in calories and fat and are a source of natural sugars, fiber and vitamins. The fruit food group is sometimes combined with the vegetable food group. I think these are the most important because even if u eat more than what you need to eat it is still fine. Unlike some of the other groups eating more fruits and vegetable is good for you.
Thursday, March 10, 2011
Tuesday, March 1, 2011
Blog #5 There have been 5 major extinction events throughout history, are humans impacting the 6th? Why or why not?
I think humans are imacting the 6th. Humans have been hunting animals, polluting the air, and causing other harmful things to our planet. For the first time since the dinosaurs disappeared, humans are driving animals and plants to extinction faster than new species can evolve, one of the world's experts on biodiversity has warned. Conservation experts have already signalled that the world is in the grip of the "sixth great extinction" of species, driven by the destruction of natural habitats, hunting, the spread of alien predators and disease, and climate change. Speaking in advance of two reports next week on the state of wildlife in Britain and Europe, Simon Stuart, chair of the Species Survival Commission for the International Union for the Conservation of Nature – the body which officially declares species threatened and extinct – said that point had now "almost certainly" been crossed.
Thursday, February 24, 2011
Blog # 4 Describe the three types of selection: directional, stabilizing and disruptive and give an example of each in your own words
Stabilizing selection favors the norm, the common, average traits in a population. Look at the Siberian Husky, a dog bred for working in the snow. Stabilizing selection has chosen a norm for the the size of the Siberian Husky. Directional selection favors those individuals who have extreme variations in traits within a population. For example people pick hounds that were the fastest in their group, from their offspring the breeders again selected the dogs that ran the fastest. By continuing this selection for those dogs, they gradually produced a dog who could run up to 64km/h (40mph). Disruptive selection, like directional selection, favors the extremes traits in a population. Disruptive selection differs in that sudden changes in the environment creates a sudden forces favoring that extreme. Think about the changes in the environment when that meteor crashed into Earth 65mya. If a plague started by the high death rate also hit these stressed animals, they would have been sorely pushed to survive. Evidence shows that they did not. So disruptive selection occurs quickly, selecting for those extreme traits that help organisms survive in the new environmental conditions.
Thursday, February 17, 2011
Blog #3 Explain what microevolution is? What are the three ways that variation occurs?
Microevolution is a change in gene frequency within a population over time. This change is due to four different processes: mutation, selection (natural and artificial), gene flow and genetic drift.
Population genetics is the branch of biology that provides the mathematical structure for the study of the process of microevolution. Ecological genetics concerns itself with observing microevolution in the wild. Typically, observable instances of evolution are examples of microevolution; for example, bacterial strains that have antibiotic resistance. Microevolution can be contrasted with macroevolution, which is the occurrence of large-scale changes in gene frequencies in a population over a geological time period (i.e. consisting of extended microevolution). The difference is largely one of approach. Microevolution is reductionist, but macroevolution is holistic. Each approach offers different insights into the evolution process. Macroevolution can be seen as the sum of long periods of microevolution, and thus the two are qualitatively identical while being quantitatively different. Mutations alter the order of bases in the nucleotides of DNA. Mutations are likely to be rare and most mutations are probably harmful, but in some instances the new alleles can be favored by natural selection. Independent assortment (recombination of chromosomes that occurs during sexual reproduction) and the Crossing over that happens during meiosis.
Population genetics is the branch of biology that provides the mathematical structure for the study of the process of microevolution. Ecological genetics concerns itself with observing microevolution in the wild. Typically, observable instances of evolution are examples of microevolution; for example, bacterial strains that have antibiotic resistance. Microevolution can be contrasted with macroevolution, which is the occurrence of large-scale changes in gene frequencies in a population over a geological time period (i.e. consisting of extended microevolution). The difference is largely one of approach. Microevolution is reductionist, but macroevolution is holistic. Each approach offers different insights into the evolution process. Macroevolution can be seen as the sum of long periods of microevolution, and thus the two are qualitatively identical while being quantitatively different. Mutations alter the order of bases in the nucleotides of DNA. Mutations are likely to be rare and most mutations are probably harmful, but in some instances the new alleles can be favored by natural selection. Independent assortment (recombination of chromosomes that occurs during sexual reproduction) and the Crossing over that happens during meiosis.
Blog # 2 Why is fossil record hard to interpret?
Fossil record is hard to interpret because it is thousands to millions of years old. The older the fossil is the harder it is for paleontologists to identify what it is. Most fossils require all of the bones to figure out what kind of animal it is and the bones could be scatter all over the world. When interpreting fossils u must be careful not to break anything. Fossils can sometimes be hard or easy depending on the size of the fossil and how old it is. Interpreting fossils takes time and one must be careful not to damage/break anything.
Thursday, January 13, 2011
What was you favorite activity/topic this year? Why was it a favorite?What was your least favorite? Why?If you could change one thing (Not the amount of homework) what would it be and how would you change it?
My favorite activity in class is doing labs. All the labs that we did were very exiting and interesting. Learning something is fun but when your actually experimenting something u learned before, that is exiting! Any labs that we did taught me many things and they were all very fun and interesting. My least favorite activity is the karoke project. We had to create our own song about biology and sing it in front of the entire class. This was the worst project i ever got because my group and i cant sing at all. Well we can sing but we sing horribly. If I could change one thing i would change the karoke project to something else like a writing project. Instead of singing a song we could write about what we learned in biology. This would be easier for me because writing a few paragraphs is easy compared to singing a song in front of your class. I would tell our teacher Ms.Malonek that a karoke project would be a bad idea because above all most people are better at writing then singing a song.
Thursday, January 6, 2011
Blog#13 How has DNA changed how we investigate crimes? What are the two main tests? Describe them
DNA has helped people solved crimes more faster and easier. Such as a strand of hair left behind at a crime scene can be used for DNA testing to find out who the strand of hair belongs to. The two main tests are RFLP and PCR testing. RFLP testing requires larger amount of DNA and the DNA must be undegraded. Crime-scene evidence that is old or that is present in small amounts are often unsuitable for RFLP testing. PCR testing often require less DNA than RFLP testing and the DNA may be partially degraded. PCR tests are also extremely sensitive to contaminating DNA at a crime scene and within the test laboratory. PCR is less direct and somewhat more prone to error than RFLP. However, PCR has tended to replace RFLP in forensic testing primarily because PCR based tests are faster and more sensitive.
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