beyond dominant & recessive alleles some alleles are neither dominant nor recessive, and many...

Beyond Dominant & Recessive Alleles • Some alleles are neither dominant nor recessive, and many traits are controlled by multiple genes.

Upload: augustus-rich

Post on 13-Dec-2015

234 views

Category:

Documents

1 download

Report

Download

Embed Size (px):

TRANSCRIPT

Beyond Dominant & Recessive Alleles

• Some alleles are neither dominant nor recessive, and many traits are controlled by multiple genes.

Incomplete Dominance • One allele is not completely dominant over

another. – The offspring has an intermediate (blend) phenotype– Ex: 4 o’clock flowers

• RR (red) X rr (white)• Rr genotype produces a pink flower

Page 3: Beyond Dominant & Recessive Alleles Some alleles are neither dominant nor recessive, and many traits are controlled by multiple genes

Incomplete Dominance

Page 4: Beyond Dominant & Recessive Alleles Some alleles are neither dominant nor recessive, and many traits are controlled by multiple genes

Codominane• Codominance – a condition in which both alleles

contribute to the phenotype of the organism.– Ex: Roan cattle

• RR (red) X WW (white) • RW genotype produces a roan cow, which has both red and

white hair.

Page 5: Beyond Dominant & Recessive Alleles Some alleles are neither dominant nor recessive, and many traits are controlled by multiple genes

Page 6: Beyond Dominant & Recessive Alleles Some alleles are neither dominant nor recessive, and many traits are controlled by multiple genes

Page 7: Beyond Dominant & Recessive Alleles Some alleles are neither dominant nor recessive, and many traits are controlled by multiple genes

Page 8: Beyond Dominant & Recessive Alleles Some alleles are neither dominant nor recessive, and many traits are controlled by multiple genes

Page 9: Beyond Dominant & Recessive Alleles Some alleles are neither dominant nor recessive, and many traits are controlled by multiple genes

Codominance

• Sickle-cell anemia follows codominant inheritance.

Page 10: Beyond Dominant & Recessive Alleles Some alleles are neither dominant nor recessive, and many traits are controlled by multiple genes

Polygenic Inheritance

• Polygenic Inheritance – some traits are determined by the interaction of many pairs of genes.– Ex: Height, weight and skin color in humans

• Skin tone depends on the amount of melanin pigment in skin cells.

• Very dark-skinned people have alleles that code for the production of melanin at many gene positions for skin color.

• Whereas, light-skinned people have alleles that code for the production of melanin at fewer gene positions for skin color.

Page 11: Beyond Dominant & Recessive Alleles Some alleles are neither dominant nor recessive, and many traits are controlled by multiple genes

Pedigrees

• A pedigree is a diagrammed family history that is used to study inheritance patterns of a trait through several generations.

• They can also be used to predict disorders in future offspring.

Page 12: Beyond Dominant & Recessive Alleles Some alleles are neither dominant nor recessive, and many traits are controlled by multiple genes

Pedigrees

• A pedigree uses symbols to illustrate inheritance of the trait.– Males = squares– Females = circles– Expresses the trait = completely shaded

shape– Carries the trait = half shaded shape– Does not express the trait = unfilled shape

Page 13: Beyond Dominant & Recessive Alleles Some alleles are neither dominant nor recessive, and many traits are controlled by multiple genes

Pedigrees

Ch 4: Mendel and Modern evolutionary theory · 2019-04-07 · Mendelian genetics recap. Dominant alleles mask the expression of recessive alleles. Homozygous: allele pairs (TT or

Important Vocabulary Genotype Phenotype Two alleles make up one genotype Alleles are either dominant or recessive There are exceptions to these rules

Not all traits are simply inherited by dominant and recessive alleles (Mendelian Genetics). In some traits, neither allele is dominant or many alleles

Exceptions to Mendelian Genetics Some alleles are neither dominant nor recessive, and some traits are controlled by multiple alleles or multiple genes

Dominant and Recessive. Doesn’t work like this recessive dominant

Mendel and Heredity - Weebly · Mendel’s Conclusions • “Principle of Dominance” –some alleles are dominant and some are recessive •Dominant alleles are expressed over

ESSON Dominant and Recessive Alleles - dvdcheng.weebly.com · Dominant and Recessive Alleles Many human traits follow a pattern of simple dominance. For instance, a gene known as

Beyond Dominant and Recessive Alleles. Incomplete Dominance: when neither allele is completely dominant over the other. · Results in the heterozygous

Allele Expression Allele expression not always as simple as dominant alleles overriding recessive ones. Alleles of a single gene may interact together

4.3 Theoretical genetics. 4.3 Theoretical genetics: Objectives 1- Define genotype, phenotype, dominant allele, recessive allele, codominant alleles, locus,

Genetics. Inheritance Patterns Dominant / Recessive Traits Incomplete Dominance Co-dominance Environmentally Influenced Multiple Alleles Polygenic Sex-linkedSex-Influenced

After Mendel Ch. 8 – 3 (con’t) Beyond Dominant And Recessive Alleles Dominant/recessive inheritance is the simplest type of gene interaction What causes

Pattern Of Inheritance Review. Define the Following Gene Alleles Locus Homozygous Heterozygous Dominant Recessive Phenotype Genotype Monohybrid cros

Mendel and the Gene Idea · Dominant vs. Recessive Alleles • The third concept is that if the two alleles at a locus differ, then: • One allele (the dominant allele) determines

Modern Genetics Genetics since Mendel. Beyond Dominant and Recessive Alleles Some alleles are neither dominant or recessive, and many traits are controlled

More Punnett squares. Complete Dominance Involves dominant and recessive alleles dominant allele always overpowers the recessive allele in appearance

11-3 Exploring Mendelian Genetics › cms › lib8 › OR01001812 › Centricity › D… · Exceptions to Mendelian Genetics! Beyond Dominant and Recessive Alleles Some alleles are

Dominant vs. Recessive Alleles

GENETICS AND INHERITANCEeccurriculum.co.za/Worksheets/Life Sciences Grade... · Dominant vs Recessive alleles An allele may be dominant- written as a capital letter OR recessive written

Beyond Dominant and Recessive Alleles

Lethal Recessive Alleles

Theoretical Genetics 4.3. 4.3.1 Define genotype, phenotype, dominant allele, recessive allele, recessive allele, codominant alleles, locus, homozygous,

There is no dominant allele, There is no recessive allele. Both alleles “blend” to result in a third phenotype

You are Here Review of what we know so far.... Classical Genetics (Mendelian Genetics) Genes and alleles Genes and alleles Dominant v. Recessive Dominant

Genes and Inheritance II Revision: most genes come in more than one form (alleles) New alleles are created by mutation and recombination Dominant and recessive

Chapter 5 (Sections 1 & 2) Heredity Review Game. An organism with two dominant alleles or two recessive alleles is called ______________. (Write both

Beyond Pure Dominance…. Some alleles are not simply dominant or recessive.. A. Incomplete dominance: Alleles are expressed as a blend. Each allele has

Chapters 11-12. * True-breeding * Hybridization * P generation * F 1 generation * F 2 generation * Alleles * Dominant * Recessive * Homozygous * Heterozygous

Recessive, Dominant, and Sex-Linked Trait Dominant, and Sex-Linked Trait Recessive, Dominant, & Sex-Linked Disorders ·some genetic traits depend on dominant and recessive alleles

12.2 Complex patterns of inheritance. Complex patterns of inheritance Mendel’s experiments show simple inheritance with recessive and dominant alleles

Theoretical Genetics Gregor Mendel. Objectives 4.3.1 – Define dominant allele, recessive allele, codominant alleles, locus,homozygous, heterozygous, genotype,

Other Laws of Inheritance Mendelian Genetics: characteristics controlled by dominant and recessive paired alleles –Many traits follow the patterns outlined

Theoretical Genetics Topic 4.3. Assessment Statements 4.3.1 Define genotype, phenotype, dominant allele, recessive allele, codominant alleles, locus,

Beyond Dominant and Recessive Alleles (1)bcsbiology.weebly.com/uploads/4/2/2/0/42205181/beyond...Beyond’Dominant’and’Recessive’Alleles •Some*alleles*are*neither*dominant*

8.1 Studying Inheritance. Lesson Objectives Distinguish between a genotype and phenotype. Understand what dominant, recessive and codominant alleles