Heredity Mendelian Genetics Ch 14 Mendelian Genetics Modern

Heredity Mendelian Genetics Ch. 14

Mendelian Genetics � Modern genetics began in the mid-1800 s in an abbey garden, where a monk named Gregor Mendel documented inheritance in peas • Known as the Father of Genetics • The first person to predict how traits are transferred from parents to offspring ü Good Experimental design and analysis ü Excellent example of scientific method Pisum Sativum

Why Pea Plants? � Small area for growing � Speedy, bountiful reproduction. � Control their fertilization – artificial cross pollination � Self pollinate

Other traits with similar patterns… Height Flower color Seed color Pod color Flower position Seed position Pod position *Always testing one trait at a time.

�P (parental) generation = true breeding plants �F 1 (first filial) generation = offspring �F 2 (second filial) generation = F 1 offspring

Mendel's Conclusions • 1. Alternative versions of genes, variations in inherited characters (alleles) at a specific locus Allele for purple flowers Locus for flower-color gene Allele for white flowers Copyright © 2008 Pearson Education Inc. , publishing as Pearson Benjamin Cummings Homologous pair of chromosomes

• 2. For each characteristic an organism inherits two alleles, one from each parent • may be identical, true-breeding P gen • may differ, hybrids, F 1 gen Copyright © 2008 Pearson Education Inc. , publishing as Pearson Benjamin Cummings

• 3. If the two alleles at a locus differ, • Dominant allele: determines the organism’s appearance (functional) • Recessive allele: no noticeable effect on appearance Copyright © 2008 Pearson Education Inc. , publishing as Pearson Benjamin Cummings

� 4. The law of independent assortment says that the combinations of alleles in the gamete will be random.

Genotype vs. phenotype �Difference between how an organism “looks” & its genetics � phenotype �description of an organism’s trait, how it LOOKS Purple, tall, curly � genotype �Description of an organism’s genetic makeup Pp, Tt, CC Always 2 alleles or letters, in pairs, capital first

Homozygous Dominant Homozygous Recessive Heterozygous Pure/True Hybrid

Monohybrid Cross: One trait at a time P = purple, p = white FLOWERS What would be the genotypes of one heterozygous parent crossed with another heterozygous parent?

Punnett squares: Punnett squares use mathematical probability to help predict the genotype and phenotype combinations in genetic crosses. Heterozygous x Heterozygous Cross F 1 generation (hybrids) Pp x Pp % genotype male / sperm female / eggs P p P PP Pp pp PP Pp % phenotype 25% PP 75% 50% Pp Purple 25% pp 25% White 3: 1 Pp pp 1: 2: 1

Writing Results �Genotype Percent �Genotypic Ratio �Phenotype Percent �Phenotypic Ratio PP Pp Pp pp

�Monohybrid cross: study 1 character �eg. flower color �Dihybrid cross: study 2 characters �eg. flower color & seed shape

Setting up a Di. Hybrid (Two traits at once) �Cross a Heterozygous Tall, Green parent with a Homozygous Tall, Hybrid Green parent �Genotypes: �Gametes:

Di-hybrid cross Yy. Rr x Yy. Rr YR Can write your results using Fractions. Yr y. R yr YR YYRr Yy. RR Yy. Rr Yr YYRr YYrr Yy. Rr Yyrr y. R Yy. Rr yy. RR yy. Rr yr Yy. Rr Yyrr yy. Rr yyrr 9/16 yellow round 3/16 green round 3/16 yellow wrinkled 1/16 green wrinkled

Dihybrid Cross �Example: Aa. Bb x Aa. Bb

The laws of probability govern Mendelian inheritance �Rule of Multiplication: � probability that 2+ independent events will occur together in a specific combination multiply probabilities of each event �Ex. 1: probability of throwing 2 sixes � 1/6 x 1/6 = 1/36 �Ex. 2: probability of having 5 boys in a row � ½ x ½ x ½ = 1/32 �Ex. 3: If cross AABb. Cc x Aa. Bb. Cc, probability of offspring with Aa. Bbcc is: � Answer: ½ x ¼ = 1/16

If cross AABb. Cc x Aa. Bb. Cc, probability of offspring with Aa. Bbcc is:

The laws of probability govern Mendelian inheritance �Rule of Addition: � Probability that 2+ mutually exclusive events will occur add together individual probabilities �Ex. 1: chances of throwing a die that will land on 4 or 5? � 1/6 + 1/6 = 1/3

Segregation of alleles and fertilization as chance events

Summary - FIX � 1. Give an example of a homozygous dominant allele (Use any letters from the alphabet) � 2. Give an example of a homozygous recessive allele (Use the same letters as in number one) � 3. Give an example of a heterozygous allele (Use the same letters as in number one) � 4. The totality of all of the genes in an organism is known as the ____.

Assignment: �Practice Worksheet Day 1 Monohybrid and Di. Hybrid Crosses - Show all work.

January 15, 2016 Happy 8 th Birthday Agenda: � Review HW � Co. Dominant and Incomplete Dominant Inheritance Patterns � Practice Worksheet � Poster Presentations Learnerator Due Tuesday! Logan!

Going over misconceptions: Tell me if the following are heterozygous or homozygous: HH Hh hh Are any of these purebred? Why or why not?

Extending Mendelian Genetics The relationship between genotype and phenotype is rarely simple Complete Dominance: heterozygote and homozygote for dominant allele are indistinguishable • Eg. YY or Yy = yellow seed Incomplete Dominance: F 1 hybrids have appearance that is between that of 2 parents • Eg. red x white = pink flowers

Codominance: phenotype of both alleles is expressed • Eg. red hair x white hairs = roan horses Multiple Alleles: gene has 2+ alleles • Eg. human ABO blood groups • Alleles = IA, IB, I • IA, IB = Codominant • ii = recessive

Blood Typing Phenotype (Blood Group) Genotype(s) Type A IAIA or IAi Type B IBIB or IBi Type AB I AI B Type O ii

Blood Transfusions �Blood transfusions must match blood type �Mixing of foreign blood clumping death �Rh factor: protein found on RBC’s (Rh+ = has protein, Rh- = no protein)

Blood Typing Problem: �A man who is heterozygous with type A blood marries a woman who is homozygous with type B blood. What possible blood types might their children have?

Polygenic Inheritance: the effect of 2 or more genes acting upon a single phenotypic character (eg. skin color, eye color, weight, height, intelligence)

Nature and Nurture: both genetic and environmental factors influence phenotype Hydrangea flowers vary in shade and intensity of color depending on acidity and aluminum content of the soil.

Summary �What is the difference between incomplete and codominance? �Blood type is an example of…. �Hair color is an example of…. �What is the difference between heterozygous and homozygous? �What is the different between pure and hybrid?

Tuesday 1/19/2016 Agenda: - Check Co. Dom/Inc Prac. - Blood Typing Activity - Begin Sex Linked Traits �New Learnerator �Due January 25 th � Theme 2 �Lab 4 #1 -10 �Lab 5 #1 -12 �Lab 6 #1 -9 � Theme 4 �Lab 13 #1 -10 �HW: Sex Linked Practice Theme 3 Learnerator DUE Today

Boy Girl

�Gene is linked to gender � Baldness � Color-blindness � Hemophilia

Sex-Linked Practice �Colorblind man vs. Carrier woman �Writing percents: (Based on gender)

Barr Bodies (Page 291 Edition 10) � Females do not make twice the number of proteins encoded by genes on the X chromosome because they have two � During fetal development, somatic cells shut off one X chromosome. � Different cells shut off the X chromosome at random, so some cells might express the genetic code contributed from the mother and some from the father. � However, once the X chromosome is shut off, all of the offspring from those original cells share the same inactive copy. � Inactive X= Barr Body � Random and Independent Process � Mosaic

Wednesday 1/20/2016 �Re-Do Blood Typing �Review Sex-Linked �Begin Pedigrees BRING TEXTBOOK TOMORROW! �HW: Are Men the Weaker Sex? Article and Questions �HW: Pedigree Practice Word Problem Worksheet 3

Review Sex Linked Worksheet �Extra Credit: Lethal Alleles

Fun Fact! (That you should know) �Dominant Alleles are not necessarily the most common allele � 1/400 babies in the USA – polydactyly � The frequency of this allele is affected by natural selection which we will learn about in a future chapter

Mendelian Inheritance in Humans Pedigree: diagram that shows the relationship between parents/offspring across 2+ generations

Pedigree Analysis Clues �Autosomal Recessive � Can skip generations �Autosomal Dominant � Every affected person has at least one affected parent, each generation will be affected �X-linked recessive �X-linked dominant � No father-son transmission � Mostly males � Can skip generations Trial and Error

Looks at Labels and Numbering

Practice

Practice

Today's Assignment �Due before you leave: First two pedigree worksheets �Homework: � Pedigree word problem worksheet � Are Men the Weaker Sex? Article and Questions � CORRECTIONS DUE BY TOMORROW!

Turn it in. com IS YOUR NAME ON ALL OF YOUR PAPERS? ! �Any corrections on your codom/inc dom worksheet �Are Men the Weaker Sex? Questions �Pedigree word problem worksheet

Thursday 1/21/16 �Bring Textbook! �Research: Genetic Disorders, Prenatal Testing, Mutations �HW: The Scent of Your Thoughts Article and Questions �HW: Learnerator Due Monday

Friday 1/22/2016 ** Turn in your homework. ** Article and Research Lecture and Practice Today: �Chapter 14 Epistasis �Chapter 15 Linked Genes - Recombination and Gene Mapping Reminder: Learnerator due Monday Cumulative “Quiz” on Monday

Epistasis �The phenotypic expression of a gene at one locus alters a gene at a second locus �Labrador Retrievers: Black coat color (B) is dominant to brown (bb) Dominant allele (E) determines if the pigment will be deposited in their hair ee = golden lab Regardless if they have a B or b

Practice Worksheet

What is a linked gene? � When two genes are close together on the same chromosome, they do not assort independently and are said to be linked. � Have a recombination frequency that is less than 50% � Whereas genes located on different chromosomes assort independently and have a recombination frequency of 50%

How can we decide how close two genes are on a chromosome? � When two genes physically close together on a chromosome, the lower the percentage of recombinant phenotypes will be seen in the offspring. � By definition, one map unit (m. u. ) is equal to one percent recombinant phenotypes. � In honor of the work performed by Morgan, one m. u. is also called one centimorgan (c. M).

Practice Female Wild Type vg+ bl+ Male vg vg bl bl Vestigial wings, Black Body

Parent Cross Female (Wild Type) Vg+ vg + bl+ vg+bl+ vgbl Male vg vg bl bl vg+bl+

Drosophila Simulation

F 1 Cross Daughter Female Dad (Test Cross) Vg+ vg bl+ bl vg vg bl bl vg+bl+ vg+bl vgbl+ vgbl No linkage: ¼ ¼ 50% Recombinant, 50% Parental ¼ ¼

Drosophila Simulation

F 2 Generation vg+bl+ vg+bl vgbl+ vgbl Actual Results: Recombinant Chromosomes: < 50% Not linked, >50% Occurrence = Linked

Bozeman 12: 05

�The closer the genes are found on the chromosome, the less likely crossing over will occur between them

Your turn! What would the relationship be between those two genes: �If a frequency of. 1% recombination occurred? �If a frequency of 50% recombination occurred?

A Linkage Map �Shows the actual distance of the genes on the chromosomes Genes A, B, and C are located on the same chromosome. Testcrosses show that the recombination frequency between A and B is 28% and between A and C is 12%. Can you determine the linear order of these genes?

Two SNOW DAYS

Wednesday 1. 27. 16 Agenda: �Cumulative Quiz �Review Linked Genes Packet (Friday) �Packet: Chromosome Mapping (HW if not completed) HW: (Due 2. 2. 16) 1. Study Tool with Practice 2. Learnerator: Theme 3: Cell Division & Heritability #16 -42

Thursday 1. 28. 16 Agenda: 1. Warm-Up Questions 2. PTC - Chi Square 3. Textbook Questions HW: (Due 2. 2. 16) 1. Study Tool with Practice 2. Learnerator: Theme 3: Cell Division & Heritability #16 -42

Warm. Up Question #1 �Use Chapter 14 (Textbook P. 276 Edition 10) for assistance: �Three characters (seed color, flower color, and pod shape) are considered in a cross between two pea plants Pp. Yy. Ii x Pp. Yy. Ii. What fraction of the offspring are predicted to be homozygous recessive for at least two of the three characters?

Multiplication Rule � Probability that 2+ independent events will occur together in a specific combination multiply probabilities of each event � Example: Black hair AND tall Addition Rule � The probability that either one of two independent events will occur � Example: Black hair OR tall

Warm. Up Question #2 How many unique gametes could be produced through independent assortment by an individual with the genotype Ff. Gg. HHJJ

Warm. Up Question #3 � Sometimes one gene can control multiple phenotypic traits in an individual. � A classic example is the human disease PKU (phenylketonuria). � This disease can cause mental retardation and reduced hair and skin pigmentation, and can be caused by any of a large number of mutations in a single gene that codes for an enzyme (phenylalanine hydroxylase) that converts the amino acid phenylalanine to tyrosine, another amino acid. � Depending on the mutation involved, this results in reduced or zero conversion of phenylalanine to tyrosine, and phenylalanine concentrations increase to toxic levels, causing damage at several locations in the body.

Warm-Up #4 �This inheritance patterns occurs when � one characteristic is controlled by two or more genes. �Often the genes are large in quantity but small in effect. �Examples are height, skin color, eye color and weight.

Warm. Up #5 A male fruit fly with a gray body and long wings is crossed with a female fruit fly having black body and apterous wings. Offspring traits: Gray body, long wings Black body, apterous wings Gray body, apterous wings Black body, long wings 42 41 9 8 a. The alleles for gray body and long wings are dominant b. The alleles for gray body and long wings are recessive c. Genes for the two traits are located on two different chromosomes and assorted independently d. Genes for the two traits are located on the same chromosome and crossing over occurred between the loci

29 th – Pd 1 and 2 1 st – Pd 3 AGENDA: �Review Hw and Midterm �Practice Test �FRQ Practice REMINDERS: �There is a good powerpoint review on my class page! Genetics Folder under Resources �Learnerator and Study Tool Practice Ques: Due 2/2/16

Di. Hybrid Linked

Sex Linked Pedigrees

Question 1 1 Point - Gene Map order is BACD - Map distance between C and D is 10 MU 1 point - Synapsis brings together homologous chromosomes during prophase of meiosis I - Crossing over is the exchange between homologous chromosomes and creates genetic variation - Crossing over creates genetic variation - Genetic variation allows for a mixture of adaptations that may prove beneficial for organism survival

Question 2 A. Math - 1: 1: 1: 1 - choosing 5 of correct expected values for each color (5) - using the correct observed values (10, 5, 7, 1, 2) Interpretation - the critical valueat 0. 05 is 9. 49 - there are 4 df - number is greater than critical value, reject, not due to chance

B. 1 Point - Birds fed more freq. on conspicuous colors - Camouflaged caterpillars not easily detected C. 1 Point - Populations drastically shift with great reduction in yellow, red, white OR majority green, brown - Camouflage provides advantage to caterpillars

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. Dd x Dd, 75% dwarf 25% normal Aa x Aa, Aa x aa or AA x aa Bb man, Bb and bb kids 0% Have it Pp x Pp 0% Have it Most people have the recessive alleles 100% wavy 50% straight 0% – all have sickled and norm cells 25% AA, 50% AB, 25% BB, 0% O 12. BB and ii 13. 50% AB, 50% Bi 14. 50% girl, 50% boy 15. Not possible 16. Xry and XRXr 17. 0% 18. 100% norm girls 50/50 boys 19. 50% colorblind boy 50% colorblind girl

Study Tool 1. 2. 3. 4. 5. 6. 7. C A or D D C 17% A 27/64 A 1/128 C 1/64

Happy Testing!