1. MP3 Review

2. Gregor Mendel In 1851 a monk named Gregor Mendel entered the University of Vienna to study science After learning about math and science he returned to his monastery and resumed his job as a high school teacher and gardener

3. Gregor Mendel Mendel called his first generation the “P” generation He called the next generation of plants the “F 1 ” generation of plants – P  F 1 The generation after F 1 was called the F 2 generation – P  F 1  F 2 What do you think the next generation was called?

4. Dominance An allele is a possible trait based on genetics Each trait has the same number of alleles from the mother and the father

5. Dominance A round seed is crossed with a wrinkled seed The F1 generation is round Which allele is dominant? A green pod is crossed with a yellow pod The F1 generation has green pods Which allele is dominant?

6. Punnett Squares A genotype is the genetic makeup of a trait A genotype is the makeup of the alleles that makeup a trait A phenotype is the physical result of genetic information It is the physical outcome of the genetic information

7. Punnett Squares A phenotype can be dominant or recessive However a genotype can be double dominant, double recessive or mixed A mixed genotype is called heterozygous A pure genotype is called homozygous

8. Punnett Squares Mendel saw a predictable pattern in the results he was getting These results were predictable because of a small chart that can be easily read The way that we can determine the outcome of any cross is a Punnett square

9. Codominance/Incomplete Dominance There are several genes that have two different dominant traits If these two dominant traits are expressed at the same time we call it codominance Codominant genes are genes that express both alleles in the pairing

10. Codominance/Incomplete Dominance Genes that blend with two dominant alleles are called incomplete dominance genes These genes can be found in many different types of organisms

11. DNA DNA is a long molecule that is made up of nucleotides Each nucleotide is made up of a… – 5 carbon sugar – Deoxyribose – A phosphate group – A nitrogenous base

12. DNA There are four bases – – Guanine – Cytosine – Thymine – Adenine They can be paired as – Guanine and Cytosine – Thymine and Adenine Only these pairings are found in DNA

13. DNA Replication 1.Unzip DNA 2.Add Base Pairs to both unzipped strands 3.Proofread the 2 new strands

14. Transcription There are three main types of RNA – mRNA – tRNA – rRNA They each have a different and specific function when it comes to making proteins

15. Transcription There are two major steps to protein synthesis The first step is to copy the information from DNA This is called transcription It involves mRNA copying the information from DNA

16. Transcription Transcription has 4 major steps 1) Identify a section of DNA to copy 2) Unzip a section of DNA 3) Create a piece of mRNA from DNA 4) Zip back up the DNA

17. Translation Translation is the process of taking mRNA and making proteins Uses all three kinds of RNA – Messenger – Ribosomal – Transfer

18. Translation There are four major steps to Translation 1) mRNA attaches to rRNA 2) mRNA is “read” by rRNA 3) tRNA bring the correct amino acids to the rRNA 4) The completed protein detaches

19. Mutations DNA can however make mistakes When a DNA makes a mistake in its own sequence of base pairs its is called a mutation A mutation can change the base pairs in DNA for the rest of DNA

20. Mutations Mistakes in DNA often present themselves in single base pairs One single base pair can change the message for an entire protein These changes can change the proteins that DNA codes for

21. Evolution Evolution is the change over time of inherited traits in a population It is a hotly debated topic It is a relatively simple definition, however it has many different aspects to it

22. Evolution Lamarck had the idea that most organisms passed on their traits based on use and disuse He believed that organisms changed over time based on their use and disuse of certain characteristics

23. Evolution However a few years later in the 1830’s a young biologist set sail on a voyage on the HMS Beagle Charles Darwin’s voyage was one of the most important events in biology

24. Natural Selection Darwin found on his journey that certain animals were better suited for their environments than other animals Darwin found that some of these animals were better suited to survival than others

25. Natural Selection Natural selection can only happen when one organism has an increased chance to spread its genes The probability that an organism will pass on its genes to the next generation is referred to as fitness

26. Natural Selection The range of traits within a population helps determine how natural selection proceeds Natural selection tends to select for certain traits and have certain other traits die out The range in traits is called genetic variation

27. Natural Selection A trait that makes an individual more likely to survive in an environment is called an adaptation Something like thick fur in a cold environment is a successful adaptation Something like thick fur in a warm environment is not a successful adaptation

28. Evidence For Evolution A fossil is the remains or traces of an organism that died long ago Fossils most often form when a trace of an organism is buried Traces of an organism can be a footprint, droppings, eggs, a corpse, etc.

29. Evidence For Evolution With these fossils we can draw conclusions about the organisms on the earth during different time periods We can line up the fossils and make a timeline of what organisms looked like and how they changed

30. Evidence For Evolution The structures of both the human hand and the bat hand are very similar The bones, the joints and the placement of the bones are all similar This goes across other animals as well

31. Evidence For Evolution Analogous structures have closely related functions but do not derive from similar ancestors A good example of this would be a bird and a butterfly They both have wings, but they are built nothing alike This is because they came from a different ancestor

32. Evidence For Evolution Darwin noticed something on his voyage that is evidence for natural selection Darwin noticed that in different parts of the world there are organisms that are closely related but are geographically far apart

33. Evidence For Evolution With the advent of modern technology we can start to study evolution and natural selection at a genetic level Modern genetics allows us to make comparisons in DNA to other organisms

34. Evidence For Evolution The process of development is similar across many organisms Many organisms have structures when they develop that are not seen in their final form For example humans have tails when they develop