Final concepts for chapter 11 mendelian genetics
This presentation is the property of its rightful owner.
Sponsored Links
1 / 38

Final Concepts for Chapter 11 Mendelian Genetics PowerPoint PPT Presentation


  • 74 Views
  • Uploaded on
  • Presentation posted in: General

Final Concepts for Chapter 11 Mendelian Genetics. Codominance Complete dominance Dihybrid cross Genotype Genotypic ratio Heterozygous Homozygous Incomplete dominance Monohybrid cross Phenotype Phenotypic ratio Probability Punnett square Testcross. Expected/predicted results

Download Presentation

Final Concepts for Chapter 11 Mendelian 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.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Final concepts for chapter 11 mendelian genetics

Final Concepts for Chapter 11Mendelian Genetics

  • Codominance

  • Complete dominance

  • Dihybrid cross

  • Genotype

  • Genotypic ratio

  • Heterozygous

  • Homozygous

  • Incomplete dominance

  • Monohybrid cross

  • Phenotype

  • Phenotypic ratio

  • Probability

  • Punnett square

  • Testcross

  • Expected/predicted results

  • Actual/observed results

  • Karyotype

  • Amniocentesis

  • Linked genes

  • Sex-linked disorders

  • Autosomal disorders

Allele

Dominant

Recessive

P-generation

F1 generation

F2 generation

Law of independent assortment

Law of segregation

Chromosomes

Pure breed

Trait


Independent assortment vs linked genes

Independent Assortment vs. Linked Genes

  • Mendel did not know about chromosomes when he proposed the Law of Independent Assortment.

  • The pea traits he studied happened to be located on different chromosomes – so they did assort independently.


Independent assortment vs linked genes1

Independent Assortment vs. Linked Genes

  • Question: How many traits do you have?

  • Question: How many chromosomes (per cell) do you have?

  • Question: Is it possible to have only one trait per chromosome?

    • No, lots of genes are carried or linked together on the same chromosome.


Independent assortment vs linked genes2

Independent Assortment vs. Linked Genes

  • Do the punnett square for the following cross – assume independent assortment.

    Cross two heterozygous tall, heterozygous red flowered plants

    T=tallR=red flower

    t= shortr = white flower


Independent assortment vs linked genes3

Independent Assortment vs. Linked Genes

What is the phenotypic ratio?

TtRr x TtRr

TR

Tr

tR

tr

TR

Tr

tR

tr


Independent assortment vs linked genes4

Independent Assortment vs. Linked Genes

9:3:3:1 ratio

9 = tall and red

3 = tall and white

3 = short and red

1 = short and white

  • PROBABILITY:

  • From this cross, 48 offspring were produced.

  • How many offspring would you expect to be tall and red?

  • How many would expect to be tall and white?

  • How many would you expect to be short and white?


Independent assortment vs linked genes5

Independent Assortment vs. Linked Genes

Now, do the following cross BUT the genes for tallness and red flowers are linked.

Cross two heterozygous tall, heterozygous red flowered plants

T=tallR=red flower

t= shortr = white flower


Independent assortment vs linked genes6

Independent Assortment vs. Linked Genes

  • Hint

    Tt

    Rr

TtRr X TtRr

Is it possible to produce a Tr gamete?


Independent assortment vs linked genes7

Independent Assortment vs. Linked Genes

TtRr X TtRr

What is the phenotypic ratio?

tr

TR

3:1

3 = Tall and Red

1 = Short and white

TR

tr


Independent assortment vs linked genes8

Independent Assortment vs. Linked Genes

  • So… out of the 48 offspring, if the genes are linked, how many would be

    • 1. tall and red?

    • 2. tall and white?

    • 3. short and red?

    • 4. short and white?

      Answer:

      tall and red = 36tall/white = 0

      short and white = 12short/red = 0

EXPECTED RESULTS!


Independent assortment vs linked genes9

Independent Assortment vs. Linked Genes

Is it possible for our Actual Results to show any flowers that are tall/white or short/red?

Yes – how?

Crossing over


Crossing over occurs in meiosis

Crossing over occurs in meiosis

Pieces of the chromosomes actual switch places.


Complete vs incomplete dominance

Complete vs Incomplete Dominance


Codominance the alleles are equally dominant

Codominance – the alleles are equally dominant

Roan CowHuman Blood Type


Sex linked traits

Sex-linked Traits

  • Traits carried on the X chromosome

Fill in the genotypes on the pedigree.


Autosomal disorders

Autosomal disorders

  • Disorders carried on non-sex chromosomes (first 22 pairs)

  • Some are autosomal dominant

    • Huntington’s disease

  • Most are autosomal recessive

    • Sickle-cell anemia

    • Cystic fibrosis


Final concepts for chapter 11 mendelian genetics

Question: How do you know if the pure bred dog you just paid big bucks for is actually pure?

GG?

Gg?


Test cross

Test Cross

  • Cross using a homozygous recessive individual with a dominant individual to determine if the dominant individual is heterozygous or homozygous dominant (pure)

  • Why use a homozygous recessive individual?


Test cross1

Test Cross

Do the punnett squares for each case:

GG x ggGg x gg


Test cross2

Test Cross

  • All offspring produced should show the dominant characteristics if the dominant parent is pure (GG) for the trait.


9 1 mendel s legacy

9-1 Mendel’s Legacy

  • F1 generation are the offspring produced from the original parental group whereas


Final concepts for chapter 11 mendelian genetics

  • The dominant factor gets expressed in the individual and the recessive factor can only be expressed when the dominant factor is absent.

    Ex. Pure Mendelian traits such as Pea Seed Shape S= smooth

    s = wrinkled


Final concepts for chapter 11 mendelian genetics

3. An allele is a hereditary factor whereas a gene is a segment of DNA that dictates a trait. Two alleles for every trait: one from mom and one from dad


Multiple choice

Multiple Choice

  • 1. C

  • 2. A

  • 3. D

  • 4. B


Final concepts for chapter 11 mendelian genetics

SHORT ANSWER

  • Strain = the body of descendants of a common ancestor, genetic crosses show how “strains” display family traits

  • Meiosis accounts for both the Law of independent assort. and Law of Segregation because the chromosomes are pulled apart randomly during anaphase 1 and 2 of meiosis


Final concepts for chapter 11 mendelian genetics

  • 3. F= orange and f = red, then orange is the dominant color

    • All flowers in the F1 generation would be orange.


Final concepts for chapter 11 mendelian genetics

  • 4 Critical Thinking: If Mendel studied traits that were linked on the same chromosomes his observations would have led him to very different conclusions. For example, he would not be able to conclude that heredity factors are independent of one another because some would always be displayed together.

  • EX: round seeds would be produced by red flowering plants only


Final concepts for chapter 11 mendelian genetics

R r B b

r b

R B

R b

r B


9 2 genetic crosses

9-2 Genetic Crosses

  • Complete dominance – one allele completely masks the expression of another

  • Incomplete dominance – both alleles are partially dominant causing an intermediate phenotype (Ex. red and white flower produce a pink flower)

  • Codominance – both alleles are expressed equally Ex. blood type AB, both A and B antigens are produced


Multiple choice1

Multiple Choice

  • 1. B

  • 2. A 266 short/ total possible of 1,064

  • 3. C

  • 4. D (test cross)

  • 5. C


Short answer

Short Answer

  • 1. A homozygous individual has two of the same alleles for a trait (AA or aa) whereas a heterozygous individual has two different alleles for a trait (Aa)

  • 2. .25 X 80 = 20 individuals

  • 3. AA, Aa are the possible genotypes, 100% of offspring will show dominant phenotype


Critical thinking

Critical Thinking

  • 4. One offspring is not sufficient enough to show if the cow is pure bred or not. The larger the sample size the more accurate the conclusion.


Wwrr x wwrr

WwRr X WwRr

  • 9 – dominant for both traits

  • 4 will have same genotype as parents

  • 1 will be homozygous dominant for both traits

  • 1 will be homozygous recessive for both traits


Gregor mendel father of genetics

Gregor Mendel: Father of genetics


  • Login