slide1 n.
Skip this Video
Loading SlideShow in 5 Seconds..
Have Graphs from Lab out and ready to b e checked PowerPoint Presentation
Download Presentation
Have Graphs from Lab out and ready to b e checked

Loading in 2 Seconds...

play fullscreen
1 / 40

Have Graphs from Lab out and ready to b e checked - PowerPoint PPT Presentation

  • Uploaded on

Have Graphs from Lab out and ready to b e checked. Genetics. Definitions. Heredity- passing of characters from parents to offspring Genetics- branch of biology that focuses on heredity Monohybrid cross-is a cross that involves one pair of contrasting traits

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'Have Graphs from Lab out and ready to b e checked' - jaunie

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

Have Graphs from

Lab out and ready to

be checked

  • Heredity- passing of characters from parents to offspring
  • Genetics- branch of biology that focuses on heredity
  • Monohybrid cross-is a cross that involves one pair of contrasting traits
  • P generation- first two individuals that are crossed
  • F₁ generation- is the offspring of the P generation
  • F₂ generation- is the offspring of the F₁ generation
  • Explains the stability of inheritance and also variations between offspring from one generation to the next
  • How long has Genetics been around?
how old is genetics
How Old is Genetics
  • From the first time man planted plants for food, to the taming of animals
  • Genetics was originally thought of as the Blending concept
    • What changed and what was the Blending concept?
blending concept
Blending Concept
  • Before the late 19th Century
  • Offspring’s genetic makeup was intermediate to that of its parents
    • Ex. Red flower crossed with white flower would yield nothing but pink flowers
    • This could not explain why for example why pink flower plants produced both red and white offspring

This did not help Darwin explain how diverse forms evolve

what changed
What Changed?
  • Gregor Mendel
    • Austrian monk
    • One of the first to use mathematics in experiments
    • Particulate Theory
    • 1860’s Garden Pea experiment
    • Considered the Father of Genetics
particulate theory
Particulate Theory
  • Based on the existence of minute particles or hereditary units
    • These units are now called Genes
  • Two laws came from this theory
    • Law of segregation
    • Law of independent assortment
garden pea pisum sativum
Garden Pea (Pisumsativum)
  • Why was the Garden pea chosen
    • Many easy to identify traits
    • Easy to control pollination
    • Easy to maintain
    • Short generation time
    • Lead to obtaining True-breeding plants
true breeding
  • What is True-Breeding?
    • It is when the offspring are the same and exactly like the parents
  • Started by choosing varieties that only differed by one trait
    • Like tall to short plants
  • Generations
    • P-parents (true-Breeding)
    • F1 is offspring
  • After first cross all offspring resembled tall parents
    • What did this mean
  • F2 generation was ¾ were tall and ¼ was short
    • This lead to Mendel to deduce tall dominate over short
  • This is referred to as a Monohybrid cross
    • Cross of a single trait
    • 3:1 ratio in F2 generation
    • This explains the Law of Segregation
monohybrid cross1
Monohybrid Cross
  • Cross between Aa to Aa
  • Results 3:1
  • Law of Segregation
    • F1 parents contained two separate copies of each hereditary factor, one dominate and the other recessive
    • Factors separated when the gametes were formed, and each gamete carried only one copy of each factor
    • Random fusion of all possible gametes occurred upon fertilization
  • Locus- location of a pair of chromosomes
  • Alleles- alternative versions of same gene
  • Dominant –fully functional protein
  • Recessive-protein with little or no function
  • Homozygous-two identical alleles
  • Heterozygous-two different alleles
  • Genotype –alleles an individual receives at fertilization(DNA)
  • Phenotype-physical appearance of the individual (protein)
    • The protein that makes the phenotype is produced by the DNA that makes up the Genotype
mendel s second experiment
Mendel’s Second experiment
  • Two true-breeding plants with two different traits
    • Ex. Tall with green pods and short with yellow pods
  • This is know as a dihybrid cross (9:3:3:1 phenotypic ratio)
    • Because the plants are hybrid in two ways
experiment 2
Experiment 2
  • Two possible out comes
    • If Dominant factors always segregate into F1 and recessive always stay together than there will be two phenotypes in F2 plants
    • If the four factors segregate into F1 gametes independently, then there would be four phenotypes among the F2 plants
      • Tall Green, Tall yellow, short green, short yellow
experiment 21
Experiment 2
  • Law of Independent Assortment
    • Each pair of factors segregate/assort independently of the other pair
    • All possible combinations of factors can occur in the gametes
      • Note the law of independent assortment applies only to alleles on different chromosomes
  • Dihybrid cross AaBb with AaBb
  • 9 with dominate AB 3With Ab 3with aB and 1 with ab
inheritance of traits
Inheritance of traits
  • Pedigree- family history that shows how a trait is inherited over several generations
  • Sex-linked gene’s- allele is located only on the X or Y chromosomes
  • Incomplete dominance- when a individual displays a phenotype that is intermediate between two parents
  • Multiple alleles- genes with three or more alleles
  • Codominance- when two dominant alleles are expressed at the same time
  • Crossing over- the exchange of genetic material between homologous chromosomes that results in recombinant chromosomes
sex linked gene s
Sex-linked gene’s
  • Most sex-linked genes are carried on the X chromosome
  • Who is most likely to exhibit these conditions?
  • Why are males more likely to exhibit a sex-linked condition?
  • Ex. Red-Green color blindness, Male pattern baldness, hemophilia
incomplete dominance
Incomplete Dominance
  • Predict the out come of a true breeding

red snapdragon with a true breeding white

snapdragon in incomplete dominance

multiple alleles
Multiple Alleles
  • Ex. Blood types
    • Determined by the three alleles (Iᴬ, Iᴮ, i)
  • Codominance and Incomplete dominance deferrer because both traits are displayed in codominance
    • Ex. Type AB blood
genetic disorders
Genetic disorders
  • Sickle Cell Anemia
  • Cystic Fibrosis
  • Hemophilia
  • Huntington’s Disease
  • Abnormalities in Karyotypes
    • Trisomy
    • Monsomy
abnormalities in karyotypes
Abnormalities in Karyotypes
  • Monosomy – chromosome having no homology, especially unpaired X chromosome
    • Turner’s syndrome- missing one sex chromosome
      • Lethal
  • Trisomy- three instances of a particular chromosome, instead of the usually two
    • Ex. Down syndrome there is an extra chromosome 21
    • Klinfelter’s syndrome were there is XXY sex chromosome
sickle cell anemia
Sickle Cell Anemia
  • Recessive genetic disorder occurs in 1out of 500 births (mostly African American)
    • Caused by mutated allele that produces a defective form of the protein hemoglobin
  • Side effects- red blood cells are sickle shaped, rupture easily, tend to get stuck in blood vessels
  • The recessive allele that causes sickle-shaped cells also helps protect the cells of heterozygous individuals from the effects of malaria
sickle cell anemia1
Sickle Cell Anemia
  • malariais a disease caused by a parasitic protozoan that invades red blood cells
cystic fibrosis
Cystic Fibrosis
  • Most common fatal, hereditary, recessive disorder among Caucasians
  • Side effects- airways of lungs become clogged with thick mucus, and ducts of the liver and pancreas become blocked
  • Treatments can relieve some of symptoms, but there is no know cure
cystic fibrosis1
Cystic Fibrosis
  • 1 in 25 Caucasians has at least one copy of a defective gene that makes a protein necessary to move chloride into and out of cells about 1 in 2500 infants in US is homozygous for the cf allele
  • Recessive genetic disorder in hemophilia
  • Impairs the blood’s ability to clot
  • Sex-linked trait
  • Over a dozen genes code for the protein involved in blood clotting
  • Mutation on 1 of these genes on the X chromosome causes hemophilia
  • Most common in Males
  • 1 in 10,000
huntington s disease
Huntington’s Disease
  • Genetic disorder caused by a Dominant allele located on an autosome
  • Symptoms- mild forgetfulness and irritability appears in thirties to forties
  • Over time causes loss of muscle control, physical spasms, severe mental illness, and eventually death
  • 1 in 10,000