1. EOC Packet #3

2. Where is DNA kept in the cell? DNA is found in the nucleus (also called chromatin) What is the name of the little structure of wound up DNA?  Chromosomes

3. What is a mutation? A mutation is a change in DNA sequence. Cause of mutations could be:  Diseases  Environment Types of changes considered mutations:  Insertion (insert extra nucleotide)  Deletion (delete nucleotide)  Substitution (substitute one nucleotide for another)

4. If a piece of DNA is mutated how can that affect future cells? The mutation can be inherited Mutations are not always negative

5. Genetic Variations A genetic variation is a variation in alleles, genes, or both in a population. It is important because it allows the stronger variations to become more prevalent within an environment. Causes of variation: change in environment, mutation, crossing over during meiosis (infinite number of different children)

6. Evolution Defined as a change in a species over time What key scientist is credited with the bulk of out understanding?  Charles Darwin

7. Evidence for Evolution Anatomy:  Homologous- same structure/different function  Example: bone structure in human arm and cat leg Embryology:  Earlier stages of development look similar Biochemical:  Similarity in DNA and proteins  ALL OF THIS EVIDENCE POINTS TO A COMMON ANCESTOR!

8. Natural Selection Organisms with the best traits will survive  Includes:  Overpopulation  Competition for Resources  Variations/Adaptations  Survival of the Fittest Example: An environment used to be very cold/snowy but has become warmer and all the snow melts. Based on the principle of natural selection would a rabbit with white fur or brown fur have a better chance of survival?

9. Genetic Variation Promotes evolution because a variety of species are produced and the environment chooses the trait that is best suited for that environment

10. Does a population have to become a separate species in order to be evolving? No- because traits can evolve but organism will still belong to the same population (ex: fur color may change but still considered to be a rabbit)