Thursday, March 3, 2011
Blog #5
There have been 5 major extinction events throughout history, are humans impacting the 6th? Why or why not?
Humans are not going to be impacting as the 6th major extintion because our world population of humans is proximately 6,903,000,000. Right now the population is increasing rapidly throughout the year. The population is expected to reach between 7.5 to 10.5 billion on the year of 2050. Even if a major disater occurs on Earth, humans will not be extincted.
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.
Directional selection is a mode of natural selection in which a single phenotype is favored, causing the allele frequency to continously shift in one direction. Stablizing selection is a type of natural selection in which genetic diversity decreasesas the population stablizes on a particular trait value. Disruptive selection describes the changes in population genetics in which extremem values for a trait are favored over intermediate values. An example for directinal selection is breeds of dogs. Dogs are used for this example bcause you can use directional selection to see which dog can run faster. an example for stablizing selection is baby birth weight. Babies with low weight loses heat more quickly and can get ill easily. An example for disruption selection would be if different color skin rabbits were placed in dark or white spots. They would hide from predators and see which rabbits with the same skin would blend in.
Directional selection is a mode of natural selection in which a single phenotype is favored, causing the allele frequency to continously shift in one direction. Stablizing selection is a type of natural selection in which genetic diversity decreasesas the population stablizes on a particular trait value. Disruptive selection describes the changes in population genetics in which extremem values for a trait are favored over intermediate values. An example for directinal selection is breeds of dogs. Dogs are used for this example bcause you can use directional selection to see which dog can run faster. an example for stablizing selection is baby birth weight. Babies with low weight loses heat more quickly and can get ill easily. An example for disruption selection would be if different color skin rabbits were placed in dark or white spots. They would hide from predators and see which rabbits with the same skin would blend in.
Thursday, February 17, 2011
Blog #3
Explain what microevolution is? What are the three ways that variation occurs?
Microevolution is the change in gene frequency within a population. One way that variation occurs is when crossing over occurs during meiosis. It also occurs when mutation alter the order of bases in the nucleotide DNA. Mutations are rare and most mutations are harmful, but some instances the new allele can be favored by natural selection.
Microevolution is the change in gene frequency within a population. One way that variation occurs is when crossing over occurs during meiosis. It also occurs when mutation alter the order of bases in the nucleotide DNA. Mutations are rare and most mutations are harmful, but some instances the new allele can be favored by natural selection.
Blog #2
Why is fossil record hard to interpret?
Fossil record is hard to interpret because the fossil record becomes fragmentary and hard to interpret. Since the fossils have been there for at least 10,000 years or more, it would be very hard to notice the shape of the animal/plant. The fossil has to be broken down in order for the main part to be taken out.
Fossil record is hard to interpret because the fossil record becomes fragmentary and hard to interpret. Since the fossils have been there for at least 10,000 years or more, it would be very hard to notice the shape of the animal/plant. The fossil has to be broken down in order for the main part to be taken out.
Thursday, February 3, 2011
Blog #1
Why is evolution a theory and not a law?
Evolution is the change over time in the proportion of individual organisms differing in one or more inherited traits. Evolution can be observed through changes in traits of a population over time.The theory of evolution is the framework that explains the observed changes of species over time. It best predicts the new observations that continue to be made in evolutionary biology.
Evolution is the change over time in the proportion of individual organisms differing in one or more inherited traits. Evolution can be observed through changes in traits of a population over time.The theory of evolution is the framework that explains the observed changes of species over time. It best predicts the new observations that continue to be made in evolutionary biology.
Thursday, January 13, 2011
Blog #14
What was you favorite activity/topic this year? Why was it a favorite?
I enjoyed doing all those labs in this biology class. Not only were the labs fun but it also taught me many different things. I like to do different biology experiments.
What was your least favorite? Why?
My least favorite activity this year would be doing the fingerprint lab yesterday. Even though I like labs, I hated this one because it got my fingers all black after. Using water and soap together didn't help get the marks away.
If you could change one thing (Not the amount of homework) what would it be and how would you change it?
I didn't get good grades on all of my tests. I wish i could change the grades on my tests. If I knew that I was going to get a bad grade, I would have studied harder than I did.
I enjoyed doing all those labs in this biology class. Not only were the labs fun but it also taught me many different things. I like to do different biology experiments.
What was your least favorite? Why?
My least favorite activity this year would be doing the fingerprint lab yesterday. Even though I like labs, I hated this one because it got my fingers all black after. Using water and soap together didn't help get the marks away.
If you could change one thing (Not the amount of homework) what would it be and how would you change it?
I didn't get good grades on all of my tests. I wish i could change the grades on my tests. If I knew that I was going to get a bad grade, I would have studied harder than I did.
Blog #13
How has DNA changed how we investigate crimes? What are the two main tests? Describe them.
DNA has changed how we investigate crimes by showing us their identity. DNA is part of your blood, saliva, hair, and fingerprints. The two main tests are PCR and RFLP.
PCR(polymerase chain reaction) is a single or few copies of DNA. It generates thousands to millions of DNA sequence. It consists of cycles of repeated heating and cooling of the reaction for DNA melting.
RFLP(restriction fragment length polymorphism) is a technique that exploits variations in homologous DNA sequences. It refers to a difference between samples of homozygous DNA molecules.
DNA has changed how we investigate crimes by showing us their identity. DNA is part of your blood, saliva, hair, and fingerprints. The two main tests are PCR and RFLP.
PCR(polymerase chain reaction) is a single or few copies of DNA. It generates thousands to millions of DNA sequence. It consists of cycles of repeated heating and cooling of the reaction for DNA melting.
RFLP(restriction fragment length polymorphism) is a technique that exploits variations in homologous DNA sequences. It refers to a difference between samples of homozygous DNA molecules.
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