Genetics & Evolution Today’s Goal I can complete a Punnett Square I can name two people and their contributions to genetics Homework Finish Vocab up to and including mutation. Study for Vocab Quiz Warm-up: Explain the quote “If I have seen further, it is by standing on the shoulders of giants” and apply this quote to Darwin’s theory and his influences- Malthus and Lyell 0:40 0:39 0:38 0:42 0:43 0:37 0:41 0:34 0:31 0:30 0:32 0:33 0:35 0:44 0:36 0:47 0:54 0:53 0:55 0:56 0:58 0:57 0:52 0:51 0:29 0:46 0:48 0:49 0:50 0:45 0:27 0:08 0:07 0:09 0:10 0:12 0:11 0:06 0:05 End 2:00 0:01 0:02 0:04 0:03 0:13 0:14 0:23 0:22 0:24 0:25 0:59 0:26 0:21 0:20 0:16 0:15 0:17 0:18 0:19 0:28 1:02 1:41 1:40 1:42 1:43 1:45 1:44 1:39 1:38 1:33 1:32 1:34 1:35 1:37 1:36 1:46 1:47 1:56 1:55 1:57 1:58 2:00 1:59 1:54 1:53 1:49 1:48 1:50 1:51 1:52 1:31 1:30 1:10 1:09 1:11 1:12 1:14 1:13 1:08 1:07 1:03 1:01 1:04 1:05 1:06 1:15 1:16 1:25 1:24 1:26 1:27 1:29 1:28 1:23 1:22 1:18 1:17 1:19 1:20 1:21 1:00

What is Genetics? Genetics – The study of how heredity information is passed from parents to offspring

The Modern Theory of Evolution = What is Genetics? The Modern Theory of Evolution = Genetics + Darwin’s Theory of Natural Selection

Law of Dominance (see above) Gregor Mendel Studied inheritance of traits in pea plants Published research shortly after Darwin’s book (but it was in an obscure journal) He received credit for his work in 1900 (15 years after his death) The pea traits he studied later became known as GENES He became the Father of Genetics Law of Dominance (see above)

What is DNA? DNA = Deoxyribonucleic acid DNA stores information Subunit = nucleotides DNA IS DOUBLE STRANDED Nucleotides contain a nitrogen base 4 different nitrogen bases adenine (A) guanine (G) thymine (T) cytosine (C) Complimentary Strands (A-T) (G-C) DOUBLE HELIX *3,000,000,000 nitrogen base pairs make you who you are*

What is a Gene? Your body is made up of cells Each cell in your body contains a nucleus Each nucleus contains pairs of chromosomes Chromosomes contain your DNA sequence A segment of DNA is called a gene A gene codes for a specific trait Most cells in your body have 46 chromosomes. Sperm and Egg cells have 23 chromosomes.

James Watson & Francis Crick and Rosalind Franklin(1953) Franklin’s x-ray of the DNA molecule – view is above helix, looking down (x pattern is from nucleotide bases) Discovered the structure of a DNA molecule (double helix) which provided details on genes & how they work

What is an Allele? Most organisms have TWO copies of every gene and chromosome (one from each parent) Alleles are the different forms of a gene for a specific trait Ex: Flowers can be violet or white

What is an Allele? REMEMBER genes exist as pairs, so often one allele is considered the dominant allele and the other the recessive allele Dominant: trait observed in the first generation when parents that have different traits are bred Given a capital letter symbol (ex: Purple flower= P) Recessive: a trait that reappears in the second generation after disappearing in the first generation when parents with different traits bred Given a lower case letter symbol (ex: White flower= p) Which is the purple allele? Purple is dominant because it “covers up” the white allele in the offspring

Dominant & Recessive Alleles Since genes are found in pairs, a pea plant could have the following combinations of alleles for flower color PP = purple Pp = purple pp = white The genetic make-up is called the genotype (PP, Pp, or pp) PP and pp is considered homozygous (all one allele type) Pp is considered heterozygous (two different allele types) The outward physical appearance for a gene is called the phenotype (purple or white), which is based on its genotype

LETS DO SOME PRACTICE PROBLEMS! is a diagram that is used to predict an outcome of a particular cross or breeding experiment. Punnett Square P = purple p = white What are the chances of having the white phenotype? What are the chances of carrying the white allele? What is the chance of having a heterozygous genotype? ¼ or 25 % ½ or 50 % ½ or 50 % LETS DO SOME PRACTICE PROBLEMS!

PRACTICE! TT x tt Tt Tt x Tt 25% 50% 25% 100 % offspring = ____

Bb Bb BB Bb Bb bb

Complete Observing Human Traits Lab

Genetics & Evolution Warm-up: Today’s Goal I can complete a Punnett Square I can describe how mutations occur Homework Finish DR How does Evolution occur AND Study for vocab quiz TOMORROW Warm-up: 5 minutes

DNA Code and Mutations The DNA Sequence shows how a species changes over time If a mutation (typo) occurs within the DNA sequence, genes can change causing alleles and traits to change Over time as more mutations accumulate the species changes

A A G A G Normal DNA (gene): Let’s say that “AAAGGG” means that you can break down a chemical in milk called phenylalanine The same sequence is copied to make egg (female) or sperm (male): A G

All egg or sperm cells will have the same sequence of “AAAGGG” so all offspring will be able to break down milk A G Unless something goes wrong when the gene is copied: A A A C G G Now this egg or sperm cell is carrying a mutation of the gene. Offspring who are born with this gene cannot break down phenylalanine from milk, which causes brain damage when it builds up in the body.

This mutation has led to 2 different variations within the population: Some babies will be disease free and can break down phenylalanine in milk Some babies will have a disease (called Phenylketonuria) and cannot break down this protein in milk

Human Genome (2001) All living things are made of genetic information We have similarities in our DNA to all animals including dogs and fruit flies. The more closely related two species are to each other the more similar their DNA code (genome) Find out your genetic code 23andMe (was $999, now $99) Visit: www.23andMe.com Other: deCODE; Navigenics

23 and Me Created by one of the founders of Google Would you use 23 and me?