Your SlideShare is downloading. ×
Mendelian Genetics
Upcoming SlideShare
Loading in...5

Thanks for flagging this SlideShare!

Oops! An error has occurred.

Saving this for later? Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime – even offline.
Text the download link to your phone
Standard text messaging rates apply

Mendelian Genetics


Published on

Published in: Education

1 Like
  • Be the first to comment

No Downloads
Total Views
On Slideshare
From Embeds
Number of Embeds
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

No notes for slide
  • There are roughly 20,000 genes in the human genome, which accounts for only about 1% of all the DNA found in a cell.
  • "introns" turned on, "exons" are segments that are turned off (not used to code for proteins).
  • P = parental, F1 = first filial, F2 = second filial generation
  • Transcript

    • 1. Mendels Laws of Genetics How traits are passed from parents to offspring.
    • 2. Genetics A gene is a segment of DNA that codes for a protein which determines one particular trait Genetics is the study of how genes are passed on from parents to offspring
    • 3. Differentiation Genes signal different cells to create proteins that give them unique shapes & functions These cells grow & divide to make tissues that form the organs of the developing baby
    • 4. Fertilization: new life is formed Life begins when two gametes (sperm + egg) join A complete set of chromosomes results (23 + 23) The zygote starts as a single cell, but soon begins to divide (via mitosis = identical cells) Genes are "turned" on and off, causing cells to differentiate (change to have different forms/jobs)
    • 5. Heredity & Inherited Traits The chromosomes from your mom and dad have given your cells instructions to make YOU! Each characteristic you inherited from your parents is called a trait (eye color, earlobe shape, height, personality traits, etc.) For each trait, you have a pair of alleles (onefrom your mother andone from your father)
    • 6. Alleles: variations of a gene Gene AllelesEye Color Blue, brown, green, hazelPea height Tall, shortPea color Yellow, greenFlower position Axial, terminal
    • 7. Gregor Mendel  An Austrian scientist-turned-monk noticed patterns in the monasterys garden  Studied the inherited traits of pea plants and found predictable, numerical ratios in the offspring  Observed some traits were dominant over others (i.e. yellow peas overpowered or occurred1822-1884 more often than green pea seeds)
    • 8. Mendels Experiments He wondered if traits seen in different generations of pea plants were • determined by environmental factors (soil composition, temperature, sunlight) OR • "handed down" by parents (chromosomes werent even discovered yet, so he had no idea how) In his highly controlled experiments, he tested the hypothesis that each trait was determined by a set (not one, but TWO) inherited factors from each parent Do you see the Scientific Method at work here?
    • 9. Dominant and Recessive Traits
    • 10. Mendel’s Crosses Observed phenotype, the outward expression of the genes the F1 generation are tall, showing that trait is dominant The dwarf plant has the recessive trait (it is overpowered by the tall allele)
    • 11. Genotypes: Genes and Alleles  The genetic make-up of an organism is its genotype  Every organism is diploid (has 2 copies of each chromosome)  Each trait is designated by a different letter  DOMINANT ALLELES ARE CAPITAL LETTERS  recessive alleles are lowercase letters
    • 12. Genotype determines Phenotype Homozygous means the two alleles are the same Heterozygous means the two alleles are different Genotype Genotype Phenotype Homozygous TT Dominant dominant Homozygous tt Recessive recessive Heterozygous Tt Dominant
    • 13. Punnet Square: Monohybrid Cross Used to predict the outcome of a genetic cross
    • 14. Dihybrid Cross What happens to two genes on different chromosomes? Homologous pairs of meiotic chromosomes line up randomly at the equatorial plane in Metaphase I The two traits separate during meiosis, resulting in offspring with different combinations of traits This results in four different possible combinations of chromosomes and genes in the gametes
    • 15. The Law of Segregation Diploid chromosomes of parents undergo meiosis Alleles separate as they become haploid egg or sperm They are combined again during fertilization to produce a diploid offspring
    • 16. Which traits are dominant?
    • 17. Independent Assortment & Segregation