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Chapter 11 Genetics STATE FRAMEWORKS 3. Genetics Central Concepts: Genes allow for the storage and transmission of genetic information. They are a set of instructions encoded in the nucleotide sequence of each organism. Genes code for the specific sequences of amino acids that comprise the proteins characteristic to that organism. 3.1 Describe the basic structure (double helix, sugar/phosphate backbone, linked by complementary nucleotide pairs) of DNA, and describe its function in genetic inheritance. 3.2 Describe the basic process of DNA replication and how it relates to the transmission and conservation of the genetic code. Explain the basic processes of transcription and translation, and how they result in the expression of genes. Distinguish among the end products of replication, transcription, and translation. 3.3 Explain how mutations in the DNA sequence of a gene may or may not result in phenotypic change in an organism. Explain how mutations in gametes may result in phenotypic changes in offspring. 3.4 Distinguish among observed inheritance patterns caused by several types of genetic traits (dominant, recessive, codominant, sex-linked, polygenic, incomplete dominance, multiple alleles). 3.5 Describe how Mendel’s laws of segregation and independent assortment can be observed through patterns of inheritance (e.g., dihybrid crosses). 3.6 Use a Punnett Square to determine the probabilities for genotype and phenotype combinations in monohybrid crosses.

Chapter 11 Genetics - duxbury.k12.ma.us · Chapter 11 Genetics STATE FRAMEWORKS 3. Genetics Central Concepts: ... 3.4 Distinguish among observed inheritance patterns caused by several

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Page 1: Chapter 11 Genetics - duxbury.k12.ma.us · Chapter 11 Genetics STATE FRAMEWORKS 3. Genetics Central Concepts: ... 3.4 Distinguish among observed inheritance patterns caused by several

Chapter 11 GeneticsSTATE FRAMEWORKS

3. Genetics

Central Concepts: Genes allow for the storage and transmission of genetic information. They are a set of instructions encoded in the nucleotide sequence of each organism. Genes code for the specific sequences of amino acids that comprise the proteins characteristic to that organism.

3.1 Describe the basic structure (double helix, sugar/phosphate backbone, linked by complementary nucleotide pairs) of DNA, and describe its function in genetic inheritance.

3.2 Describe the basic process of DNA replication and how it relates to the transmission and conservation of the genetic code. Explain the basic processes of transcription and translation, and how they result in the expression of genes. Distinguish among the end products of replication, transcription, and translation.

3.3 Explain how mutations in the DNA sequence of a gene may or may not result in phenotypic change in an organism. Explain how mutations in gametes may result in phenotypic changes in offspring.

3.4 Distinguish among observed inheritance patterns caused by several types of genetic traits (dominant, recessive, codominant, sex-linked, polygenic, incomplete dominance, multiple alleles).

3.5 Describe how Mendel’s laws of segregation and independent assortment can be observed through patterns of inheritance (e.g., dihybrid crosses).

3.6 Use a Punnett Square to determine the probabilities for genotype and phenotype combinations in monohybrid crosses.

Page 2: Chapter 11 Genetics - duxbury.k12.ma.us · Chapter 11 Genetics STATE FRAMEWORKS 3. Genetics Central Concepts: ... 3.4 Distinguish among observed inheritance patterns caused by several

Genetics- the scientific study of heredity.Heredity- passing of genetic traits from parent to offspring.Trait- any characteristic that can be passed from parent to

offspring.The varied patterns of stripes on Zebras are due to differences in their genetic codes.

What are some of your traits?

Page 3: Chapter 11 Genetics - duxbury.k12.ma.us · Chapter 11 Genetics STATE FRAMEWORKS 3. Genetics Central Concepts: ... 3.4 Distinguish among observed inheritance patterns caused by several

Humans have controlled traits for years. ex. Indians with corn, breeding of dairy cows.

Aristotle- pangenes in blood. Bloodlines and Blood Relative.

Gregor Mendel 1822- 1884*Became a priest and studied math and science at the

University of Vienna.*Spent 14 years working in a monastery and teaching

at the high school.*Was in charge of the monastery garden and carried

out his work on garden pea plants.

Page 4: Chapter 11 Genetics - duxbury.k12.ma.us · Chapter 11 Genetics STATE FRAMEWORKS 3. Genetics Central Concepts: ... 3.4 Distinguish among observed inheritance patterns caused by several

Plant ReproductionA flower is the reproductive structure of a plant. It contains the male and female sex organs which produce pollen and eggs by meiosis.

Fertilization results in a zygote which is contained in a seed.

Page 5: Chapter 11 Genetics - duxbury.k12.ma.us · Chapter 11 Genetics STATE FRAMEWORKS 3. Genetics Central Concepts: ... 3.4 Distinguish among observed inheritance patterns caused by several

Mendel's Experiments*Pea plants are easy to grow so he could study many generations.*Self Pollenating*Show several traits in contrasting forms. No blending inheritance.What he did:

Page 6: Chapter 11 Genetics - duxbury.k12.ma.us · Chapter 11 Genetics STATE FRAMEWORKS 3. Genetics Central Concepts: ... 3.4 Distinguish among observed inheritance patterns caused by several

Mendel’s Experiments

Dominant Trait Recessive Trait F1 Generation F2 Generation Ratio

Red Flowers White Flowers All Red 705 Red/224 White 3.15 : 1

Smooth Seeds Wrinkled Seeds All Smooth 5474 Smooth/1850 Wrinkled 2.96 : 1

Yellow Seeds Green Seeds All Yellow 6022 Yellow/2001 Green 3.01 : 1

Inflated Pods Constricted Pods All Inflated 882 Inflated/299 Constricted 2.95 : 1

Green Pods Yellow Pods All Green 428 Green/152 Yellow 2.82 : 1

Axial Flowers Terminal Flowers All Axial 651 Axial/207 Terminal 3.14 : 1

Tall Stems Short Stems All Tall 787 Tall/277 Short 2.84 : 1

Page 7: Chapter 11 Genetics - duxbury.k12.ma.us · Chapter 11 Genetics STATE FRAMEWORKS 3. Genetics Central Concepts: ... 3.4 Distinguish among observed inheritance patterns caused by several

Mendel's Conclusions: Vocab: alleles are different forms of a gene.

i.e. red flower allele and white flower allele*Parent plants contain two alleles (genes) for each trait. *Parent plants pass only one allele (gene) to their offspring. Therefore, gametes

contain only one gene for each trait.Mendel's 3 Principles:The Principle of Dominance: some alleles are dominant and others are recessive.The Principle of Segregation: alleles for each trait segregate independently into

gametes. Dominant alleles get passed equally to recessive alleles.

The Principle of Independent Assortment: alleles for one trait are sorted independently of the alleles for other traits during

gamete formation.

Page 8: Chapter 11 Genetics - duxbury.k12.ma.us · Chapter 11 Genetics STATE FRAMEWORKS 3. Genetics Central Concepts: ... 3.4 Distinguish among observed inheritance patterns caused by several

ProbabilityExpected vs. Observed

Page 9: Chapter 11 Genetics - duxbury.k12.ma.us · Chapter 11 Genetics STATE FRAMEWORKS 3. Genetics Central Concepts: ... 3.4 Distinguish among observed inheritance patterns caused by several

Mendel's Experiments: Monohybrid Crosses

Page 10: Chapter 11 Genetics - duxbury.k12.ma.us · Chapter 11 Genetics STATE FRAMEWORKS 3. Genetics Central Concepts: ... 3.4 Distinguish among observed inheritance patterns caused by several

Test Cross- Allows you to determine the genotype of an unknown phenotype.

Trait: Rabbit Fur Color

B=brown fur allele b= white fur allele

If you have a brown furred rabbit, do you know its genotype for sure?

Page 11: Chapter 11 Genetics - duxbury.k12.ma.us · Chapter 11 Genetics STATE FRAMEWORKS 3. Genetics Central Concepts: ... 3.4 Distinguish among observed inheritance patterns caused by several

Incomplete Dominance (Blending Inheritance) when a heterozygous genotype results in an intermediate phenotype. There are no dominant nor recessive alleles.

Ex. Trait: Snap Dragon Flower Color

ALLELES GENOTYPES PHENOTYPES

R= red flower allele RR Red flowered plants

W= white flower allele WW White flowered plants

RW Pink flowered plants (incomplete dominance)

Page 12: Chapter 11 Genetics - duxbury.k12.ma.us · Chapter 11 Genetics STATE FRAMEWORKS 3. Genetics Central Concepts: ... 3.4 Distinguish among observed inheritance patterns caused by several

Cross a red flowered snap dragon with a white flowered snap dragon. What are the genotypic and phenotypic ratios in the F1 generation?

Page 13: Chapter 11 Genetics - duxbury.k12.ma.us · Chapter 11 Genetics STATE FRAMEWORKS 3. Genetics Central Concepts: ... 3.4 Distinguish among observed inheritance patterns caused by several

Multiple Alleles and Co-dominance Ex. Trait: Human Blood Types

ALLELES GENOTYPES PHENOTYPES

IA = Type A allele IA IA and IA i Type A Blood

IB = Type B allele IB IB and IB i Type B Blood

i = Type O allele i i Type O Blood

*multiple alleles (3) in IA IB (co-dominance) Type AB Blood the population

Page 14: Chapter 11 Genetics - duxbury.k12.ma.us · Chapter 11 Genetics STATE FRAMEWORKS 3. Genetics Central Concepts: ... 3.4 Distinguish among observed inheritance patterns caused by several

Sex-linked or X-linked traits- genes that appear on the X chromosome.

The color vision gene is located on the X chromosome.

B = Normal color vision allele GENOTYPES PHENOTYPES

b = Color Blind allele XB XB Normal Color Vision Female XB Xb Normal Color Vision Female (carrier) Xb Xb Color Blind Female

XB Y Normal Color Vision Male

Xb Y Color Blind Male

Page 15: Chapter 11 Genetics - duxbury.k12.ma.us · Chapter 11 Genetics STATE FRAMEWORKS 3. Genetics Central Concepts: ... 3.4 Distinguish among observed inheritance patterns caused by several

Sex-linked or X-linked traits- genes that appear on the X chromosome.

The color vision gene is located on the X chromosome.

B = Normal color vision allele GENOTYPES PHENOTYPES

b = Color Blind allele XB XB Normal Color Vision Female XB Xb Normal Color Vision Female (carrier) Xb Xb Color Blind Female

XB Y Normal Color Vision Male

Xb Y Color Blind Male

Page 16: Chapter 11 Genetics - duxbury.k12.ma.us · Chapter 11 Genetics STATE FRAMEWORKS 3. Genetics Central Concepts: ... 3.4 Distinguish among observed inheritance patterns caused by several

Cross a normal color vision man with a normal color vision woman, whose father was colorblind. What are the male and female genotypic and phenotypic ratios of their children?

Page 17: Chapter 11 Genetics - duxbury.k12.ma.us · Chapter 11 Genetics STATE FRAMEWORKS 3. Genetics Central Concepts: ... 3.4 Distinguish among observed inheritance patterns caused by several

Dihybrid Crosses- crosses that involve two traits.

Traits: Mendel's Pea Plant Height and Flower Color.

T = Tall Plant Allele R = Red Flower Allele

t = Short Plant Allele r = White Flower Allele

Cross a pure bred tall, purebred red flowered plant with a short plant with white flowers.

Page 18: Chapter 11 Genetics - duxbury.k12.ma.us · Chapter 11 Genetics STATE FRAMEWORKS 3. Genetics Central Concepts: ... 3.4 Distinguish among observed inheritance patterns caused by several

F.O.I.L.-USED TO FIND ALL THE POSSIBLE COMBINATIONS OF ALLELES FOR TWO TRAITS.