Presentation on theme: "Do Now: 1. Certain acquired characteristics, such as mechanical or mathematical skill may be inherited. 2. Certain thoughts or experiences of a mother."— Presentation transcript:
1Do Now:1. Certain acquired characteristics, such as mechanical or mathematical skill may be inherited.2. Certain thoughts or experiences of a mother mark or alter the hereditary makeup of an unborn child.3. Color blindness is more common in males than in females.4. A person may transmit characteristics to offspring which he/she does not show.5. Certain inherited traits may be altered by the stars, planets or moon early in development.6. The total number of male births exceeds female births each year.
2Objectives: To distinguish between heredity and inheritance To describe Mendel’s experiments in heredityTo compare heterozygous vs. homozygous and dominant vs. recessive.
8Pollination – transfer of pollen from anthers to stigma in flowers 1) self pollination occurs within the same flower or same plant2) cross pollination occurs between different plants
9Mendel’s Crosses with Pea Plants XPure tallplantsPure shortplantsparentalgenerationP1Cross Pollinationfirst filialgenerationAll Tall plantsF1Self Pollinationsecond filialgeneration787 tall plants, 277 short plantsF23 to ratio
18Example of Genotype and Phenotype TallTTgenotypephenotype
19DO NOWA man with a widow’s peak marries a woman with no widow’s peak. Widow’s peak is a dominant trait. Identify the following:Man’s geneotype:Woman’s genotype:Man’s phenotype:Woman’s phenotype:Use the letter W or w.
20Homozygous – when both alleles of a pair are the same dominantTThomozygousrecessivett
21Heterozygous – when both alleles of a pair are not the same (tall)Tt
22In rabbits, black fur color is dominant over brown fur color B = black furb = brown furbbBBorBb
23Think – Pair - ShareIf Fred Flintstone is heterozygous for black hair.(B=Black, b=blonde)What is Fred’s genotype?What is Fred’s phenotype?Tweety bird is YY. (Y= yellow feathers, y=brown feathers)1. What is his genotype?2. What is his phenotype?3. Is he heterozygous or homozygous? Explain.
24Think – Pair - ShareWorksheet on homozygous/heterozygous and dominant and recessive.Due Tomorrow (or next time I see you!)
25Homework Create flashcards with the definition and an example HeterozygousHomozygousGenotypePhenotypeDominantRecessiveAlleleGeneGenetics
26Do NowSponge Bob Square pants is heterozygous for brown eyes. Sandy is also heterozygous for brown eyes. Create a punnett square to determine the possible outcomes of their children.Show phenotype and genotype ratios.
27**Take Out your Homework!!! Objective:To describe Mendel’s 3 laws of inheritanceComplete a Monohybrid cross**Take Out your Homework!!!
311) Law of DominanceEach trait is controlled by 2 factors, one factor (dominant ) may mask the other factor (recessive ) preventing it from having an effect.P1F1F2
32w W W w 2) Law of Segregation Each allele a person has separates into different gametesEx. Ww – one W goes in one sperm and the other w goes into another spermWwSperm
333) Law of Independent Assortment Gene pairs (homologous) will separate randomly into gametes (metaphase I of meiosis)
34Monohybrid Cross R= Can roll your tongue r= Can’t roll your tongue Genotype Ratio:Phenotype Ratio:Rr
35Genotypic vs. Phenotypic Ratios Phenotype Ratio:Ratio of different physical traitsEx) Brown eyes ¼ or 25%Genotype Ratio:Ratio of the different possible allelesEx) Tt = ¼ or 25%
36Lets Try a Monohybrid together! Daffy Duck is heterozygous for black feathers. Daisy Duck is homozygous for yellow feathers. Set up a punnett square and determine probabilities of their potential offspring. (Both genotype and phenotype ratios!)B = Black b = yellow
37Practice!Get with a partner and work on the sample problems!
38DO NOW:Sleeping Beauty has freckles. Her prince charming is heterozygous for no freckles. What are the chances of her children having freckles? Please show your work.
39Do Now Being able to roll your tongue is a dominant trait. 1. Write down your phenotype and genotype.2. Are you positive that’s your genotype?
40Test cross – an individual with unknown genotype is crossed with a homozygous recessive individual used to determine the genotype of any individual whose phenotype is dominant
41Lets Try a Test CrossSpongebob squarepants doesn’t know whether or not he is Homozygous Dominant or Heterozygous for his yellow color. The recessive trait is a white sponge. Let’s say that we perform a “test cross” on spongebob (spongebob + a white female sponge) and all of the baby sponges are yellow. What would spongebob’s genotype be?
42Objectives:To set up and complete a dihybrid cross.
43What is a dihybrid Cross? A dihybrid cross allows us to predict possible outcomes of offspring that will have 2 traits simultaneously.Ex: what would you get if you crossed a Brown-haired brown-eyed male with a blonde-haired blue-eyed female? How many of the children would have brown hair and brown eyes? Brown hair and blue eyes? Blonde hair and brown eyes? Blonde hair and blue eyes?
45Setting up Dihybrid Crosses 1. Determine parent genotypes2. Determine alleles to be passed down3. Set up punnet square4. Determine outcomePhenotype RatioGenotype Ratio
46More PracticeMickey Mouse is heterozygous for Round ears and homozygous for Black eyes. Minnie Mouse also is homozygous for Floppy ears and heterozygous for Black eyes. Determine genotype and phenotype ratios. (B=black, b=brown, R=round, r= floppy.)
47Dihybrid Crosses Looking at two different traits Ex. Hair color and eye colorB=brown eyesb=blue eyesR=Brown hairr=blonde hairMother is heterozygous for both traitsFather is heterozygous for eye color and homozygous dominant for hair color
48What could the phenotypes and genotypes be of their children?
49Objectives: To define gene linkage and polypoidy. To understand pedigrees and figure out how to use one.
50Pedigree Shows history of a trait in a family Allows researchers to analyze traits within a family
67Sickle Cell DiseaseAffects red blood cells and ability to transport oxygen.Homozygous recessive alleles=Heterozygous=Homozygous dominant alleles=
68Sickle Cell and Malaria People who are heterozygous for sickle cell, have a higher resistance to malaria.
69Do NowA man who is a breeder of roan cows wants to cross two roan cows to produce more roan cows. After the two cows mate, the offspring are one red cow and one white cow. He is very disappointed. Explain why this happened. Provide a punnet square.