1 / 25

Genes & Alleles Genotype & Phenotype Homozygous & Heterozygous

Key to Heredity. Genes & Alleles Genotype & Phenotype Homozygous & Heterozygous. Created by Sima Mathew and Jennifer Dietz. Gregor Mendel known as : : T HE FATHER OF GENETICS.

zahi
Download Presentation

Genes & Alleles Genotype & Phenotype Homozygous & Heterozygous

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. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Key to Heredity Genes & Alleles Genotype & Phenotype Homozygous & Heterozygous Created by Sima Mathew and Jennifer Dietz

  2. Gregor Mendel known as:: THE FATHER OF GENETICS. - laid the foundations for the SCIENCE OF GENETICS through his study of inheritance patterns of traits in pea plants.

  3. What is heredity or inheritance? • Passing of traits from parent to offspring or from one generation to the next. • Genes are the coded instructions that define our traits.

  4. How are genes inherited? • Humans have 2 sets of chromosomes for a total of 46 chromosomes. Each parent contributes only 1 set of chromosomes to their child. • When a sperm cell (23 chromosomes) and an egg cell (23 chromosomes) join during fertilization, it results in a zygote (46 chromosomes).

  5. What is a trait? • Notable feature or quality in a person. What are the two types of traits? • Physical traitsare traits that can be seen such as eye or hair color • Behavioral traitsdemonstrate the way one acts such as “the fetching behavior of golden retrievers”.

  6. Phenotype • Phenotype is another word for physical trait (in other words, it describes how someone looks) • Examples of phenotypic words are: tall, short, brown hair, straight hair, fat, skinny, fair skin, freckles, etc. Can you think of anymore? On your notes, write at least 4 phenotypic words that describe YOU!

  7. REMEMBER!! • Phenotype describes things you can see!!!

  8. What do you think person’s phenotype would be?

  9. How would you describe this phenotype?

  10. Remember?? • REMEMBER: Mom gives you one half of your genes, and your dad gives you the other half…. • sperm + egg = YOU! Together, these two genes (one from mom and one from dad) represent your genotype • Each gene is represented by one letter.

  11. Genotype • Genotype is the genetic makeup of an organism’s traits represented by letters Genotype codes for phenotype T = tall t = short

  12. GENE Important vocab to know The factors that carry all traits = ALLELES Two different forms of the same gene =

  13. Example • Gene = height • Alleles = tall; short

  14. Example • Gene = eye color • Alleles = green, blue, brown

  15. Example • Gene – hair texture • Alleles – straight, wavy, curly

  16. Example • Gene – thumb • Alleles – hitchhiker’s thumb, straight thumb

  17. Dominant vs. Recessive • Think of a person who never lets you talk during a conversation – that person DOMINATES the conversation. A Dominant Allele: allele that is expressed (the one that you see). A Recessive Allele: allele that is masked or hidden (not shown)

  18. DOMINANT T RECESSIVE t Mendel's Key Terms Which allele is expressed over another and represented by a capital letter? Which allele is usually masked or appears less in the population and represented by a lowercase letter?

  19. Dominant or Recessive? A F r h G t d

  20. Check Yourself A – dominant F - dominant r – recessive h - recessive G - dominant t - recessive d - recessive

  21. When both alleles are theSAMEit is called When the alleles areDIFFERENTit is called BB B bb homozygous for brown hair heterozygous for brown hair homozygous for red hair Mendel's Key Terms B = brown hair b = red hair b HOMOZYGOUS HETEROZYGOUS

  22. Homozygous or Heterozygous? RR Jj tt Hh aa

  23. Check Yourself RR - homozygous Jj - heterozygous tt - homozygous Hh - heterozygous aa - homozygous

  24. PHENOTYPE – physical characteristics that you SEE Ex. Straight hair, red hair, freckles, lactose intolerant, tall, blue eyes Mendel's Key Terms You inherit two alleles for each gene (trait).1 from MOM! 1 from DAD! • GENOTYPE – genetic makeup represented by letters • Ex. RR, Tt, Ffgg, YyEePp

  25. Mendel’s 1st Law of Inheritance • Principle of Dominance: when there is a dominant allele and a recessive allele inherited together for a particular gene, the dominant allelewill ALWAYS be expressed. B Brown b Dominant Brown hair allele Recessive red hair allele Express the dominant allele for brown hair

More Related