Regents Biology Welcome to Semester 2 Topics  Genetics  Classification  Viruses/Bacteria  Very brief – plants and fungi  Animal Development  Animal Phyla  Human Body  Fresh Start for your Semester 2 Grade  Full effort, come in for help, get homework done, take notes, study for tests…set goals for a higher grade

Regents Biology Agendas Out  Plan for this week – write down your homework (use your agendas this semester – they help!)  Semester 1 Final Exam – if you want to go through the test, you may come in on your own time to check your answers (you will be given key to check with)

Regents Biology Zebra  Like our fingerprints – no two patterns are exactly the same  3 different species – each species does have a general pattern  Stripes distort distance at dawn and dusk – tricks predators  Social animals – graze together, groom each other  Some herds can have over a thousand members  Look-out for each other and protect the wounded of their group

Regents Biology Cucumber Genetics  In about 2 weeks we will be tasting cucumber cotyledons to determine whether they are the bitter or non-bitter variety – then we will collect data to determine the genes that code for bitter/non-bitter and their frequency  Today, you will be planting 1 seed in a pot of soil – don’t place seed too deep in soil  Water your plant  Label your name and hour on the pot/cup  WASH HANDS AFTER PLANTING

Regents Biology Genetics *study of passing on of characteristics from parents to offspring Why do we look the way we do?

Regents Biology Inheritance of chromosomes  Meiosis = making sex cells (egg and sperm)  Egg + sperm  zygote egg sperm zygote fertilization mitosis & development meiosis

Regents Biology Inheritance of genes  On the chromosomes passed from Mom & Dad to offspring are genes  may be same information  may be different information eye color (blue or brown?) eye color (blue or brown?)

Regents Biology Effect of genes  Genes come in different versions  brown vs. blue eyes  brown vs. blonde hair  alleles

Regents Biology What did we show here?  Genes come in “versions”  brown vs. blue eye color  alleles  Alleles are inherited separately from each parent  brown & blue eye colors are separate & do not blend  either have brown or blue eyes, not a blend  Some alleles mask others  brown eye color masked blue

Regents Biology Genes affect what you look like X BB bb Bb Where did the blue eyes go??

Regents Biology Genes affect what you look like… X Bb bb Bb bb Why did the blue eyes stay??

Regents Biology Genes affect what you look like… X Bb BB or Bb bb Where did the blue eyes come from??

Regents Biology How does this work? eye color (brown?) hair color eye color (blue?)  Paired chromosomes have same kind of genes  but may be different alleles

Regents Biology Yunnan Snub-nosed Monkeys  Old world monkeys  Live in small part of China mountains, and a small colony is found in Tibet  Endangered  Specialist feeders – eat only lichens growing on the bark of pine trees  Named from short, stumpy nose  Live high up in mountain forests, up to 4700 meters up!  World’s highest living non-human primates  Live in groups of  Little is known about them – hard to study!  Not discovered until the 1990’s!

Regents Biology The Father of Genetics  Gregor Mendel – first person to predict how traits pass between generations  Studied pea plants  Self-pollination and cross-pollination  Studies 1 trait at a time - Monohybrid  Studies short vs. tall plants over several generations, then also studies other plant traits separately

Regents Biology Generations  P 1 = Parent  F 1 = First Filial (first set of offspring)  F 2 = Second Filial (second set of offspring)

Regents Biology Extending Mendelian genetics  Mendel worked with a simple system  peas are genetically simple  most traits are controlled by single gene  each gene has only 2 version  1 completely dominant (A)  1 recessive (a)  But its usually not that simple!

Regents Biology Traits are inherited as separate units 1 from Mom 1 from Dad  For each trait, an organism inherits 2 copies of a gene, 1 from each parent  a diploid organism inherits 1 set of chromosomes from each parent  diploid = 2 sets of chromosomes  Sex cells are haploid (1 set of chromosomes) homologous chromosomes

Regents Biology Laws of Genetics  Law of Segregation: - parent has two alleles for a gene - those alleles separate during meiosis - when male and female gametes (sperm and egg) pair, they randomly pair for different combinations

Regents Biology Laws of Genetics 2  Law of Independent Assortment: - genes for different traits are inherited independent of each other - ex. Height and color

Regents Biology Making gametes BB= brown eyes bb= blues eyes Bb= brown eyes BBbbBbBb  brown is dominant over blue  blue is recessive to brown Remember meiosis! B B b b B b

Regents Biology How do we say it? BB= brown eyes bb= blues eyes Bb= brown eyes 2 of the same Homozygous 2 different Heterozygous BB B B bb b b BbBb B b homozygous dominant homozygous recessive

Regents Biology Genetics vs. appearance  There can be a difference between how an organism looks & its genetics  appearance or trait = phenotype  brown eyes vs. blue eyes  genetic makeup = genotype  BB, Bb, bb 2 people can have the same appearance but have different genetics: BB vs Bb

Regents Biology Traits Inventory  Let’s check some of your traits and alleles you have  Traits Inventory Packet

Regents Biology Punnett squares (predict possible offspring) Bb x Bb male / sperm female / eggs X BB BbBbbb BbBb B b Bb

Regents Biology Genetics vs. appearance eye color (brown) eye color (brown) eye color (blue) eye color (brown) vs. BB B B Bb B b How were these brown eyes made?

Regents Biology Woof! Woof! Any Questions?

Regents Biology Dog Genes and Pea Pod WS  Let’s practice what we just went over!  Let’s do one Punnet Square Together – then take 8-10 minutes to complete the rest of the worksheet (both sides)

Regents Biology Monohybrid Cross Worksheet  Due Thursday – you will have some time to work tomorrow if you finish lab early