1 / 15

Understanding Dominant and Recessive Alleles in Genetics

Explore the concepts of dominant and recessive alleles and how they influence traits. Learn about alleles, genes, and hybrid organisms through simple genetics problems. Discover why certain traits skip generations and the significance of Mendel's work in genetics.

paytah
Download Presentation

Understanding Dominant and Recessive Alleles in Genetics

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. January 16, 2013 (A Day) Agenda • DSJ #19 • Genetics: Dominant and Recessive Alleles (Notes) • Simple Genetics Problems (Worksheet) • DSR #19

  2. January 17, 2013 (B Day) Agenda • DSJ #19 • Genetics: Dominant and Recessive Alleles (Notes) • Simple Genetics Problems (Worksheet) • DSR #19

  3. DSJ #19 Science Notebook – Page 40B Prompt: When Mendel crossed a tall pea plant with a short pea plant, the result was an entire generation of tall plants. But when those plants self-pollinated, it resulted in the next generation having a mix of both tall and short plants. In 5 sentences or more, describe why you think the short trait “skipped” a generation.

  4. Dominant and Recessive Alleles

  5. Learning Objective • Students will know what alleles are and the two types of alleles.

  6. Dominant and Recessive Alleles • Genes are the factors that control a trait. • Alleles are the different forms of a gene.

  7. Dominant and Recessive Alleles • A trait controlled by a dominant allele always shows up in the organism when the allele is present. • So, a recessive allele will be masked when a dominant allele is present

  8. Dominant and Recessive Alleles 11. A recessive trait will only show up if both alleles are recessive.

  9. Hybrids 12. 13. & 14. • The plants both contain dominant and recessive alleles. Dominant Recessive • But why are they both tall?

  10. Symbols for Alleles 15. A dominant allele is represented by a capital letter. 16. A recessive allele is represented by the lower case version of the letter . • For example, the allele for tall stems is represented by: • T • For example, the allele for short stems is represented by: • t

  11. Symbols for Alleles 17. TT tt Tt Tt

  12. Significance of Mendel’s Work • People used to think that if you mixed traits you would have a blended form. If this were true, all of Mendel’s pea plants would have a medium height. • Mendel’s work wasn’t recognized in his lifetime. • But, in 1900 three different scientists discovered his work and recognized the importance of his ideas. 18. Because of this, he is often called the Father of Genetics.

  13. Glue in SNB • 40A - Genetics: Dominant and Recessive Alleles (Notes) • 41B – Simple Genetics Problems

  14. DSR #19 • Science Notebook – Page 40B (Under DSJ #19) • Prompt: What is a dominant allele and what is it represented by? What is a recessive allele and what is it represented by? What kind of alleles does a hybrid organism have?

More Related