blog #4

Describe the three types of selection: directional, stabilizing and disruptive and give an example of each in your own words.


Stabilizing is when natural selection works against the two extremes of a trait to make the population more uniform. Stabilizing selection might work on the birth weight of human babies to keep them at an intermediate weight, because babies that are too big or too small have less chance of being born healthy.


Directional selection is a type of selection works to select the extreme of one trait. In a population of plants, flowers with the brightest color are selected for in order to attract the most pollinators.


Disruptive type of selection selects against the mean of the population.If there are two types of seeds to eat for a population of birds, either of two different beak shapes (sharp or blunt) might be selected for, but a beak that's the average of the two shapes might not be particularly good at eating either seed, so it would be selected against.

Blog # 2 Why is fossil record hard to interpret?

Fossils are hard to interpret because they take long time to form.  Takes hundreds or even thousands of millions of years to form one.  Thats why fossils are so rare and expensive.  They're hard to find also since most of them vanish or is bury deep.  The animals that are extinct are the ones we learn from.  Like dinosaurs they're hard to find.

blog #3

Microevolution is a change in gene frequency within a population. It is evolution resulting from a succession of relatively small genetic variations that often cause the formation of new subspecies. There are 5 ways microevolution can occur: mutations, selection, migration, genetic drift and nonrandom mating!  Thats what microevolution is and how it occurs.

Semester 2: blog 1

Why is the theory of evolution still a theory and not a law?

 Theories can NEVER become laws. And laws can NEVER become theories. A law is a fact. A theory is an explanation for facts. A theory is an EXPLANATION for observed facts. A good theory explains many facts. A law is a fact that is observed to be universally true. Note that laws are OBSERVED to be true, not proven to be true. A LAW DESCRIBES A FACT.  A THEORY EXPLAINS MANY FACTS.

LAST BLOG OF SEMESTER

What was you favorite activity/topic this year? Why was it a favorite?
My favorite activity this year was burning the chips , it was a lab.  It was my favorite because i got to eat the chips and burning things are fun.  My favorite topic was about DNA fingerprints.  It taught me a lot about fingerprints and what types there are.  My least favorite was when we did the kim chi.  It smelled like crap real nasty  i didn't want to touch it.  If i could change one thing i would change how we don't read the books because they are boring.

DNA changes

DNA changed how we investigate crimes because of blood and fingerprints. It can show who has been here and detect the criminal or show who has been killed.  The 2 main tests are blood tests and fingerprint tests.  DNA has helped us solve lots of crimes especially the methods where they look for blood cells or fingerprints.  It has changed the world a lot.

blog 12

The parents are geno typically heterozygous in all genes.  They all express the dominant trait, while their offspring is homozygous recessive. Homozygous dominant, and heterozygous, with some expressing the dominant traits, others the recessive traits. If the genes are unlinked, so that the traits are independent, you'd have 2^4 = 16 different combinations when experimenting with 4 genes. Thats why P1 is alike and all F1 is different. Those are the reasons.


http://wiki.answers.com/Q/Why_Mendel_perform_experiments_on_pea_plant