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Topic : Genetics Aim : How do we use pedigree charts to follow a trait through generations of a family? Do Now : Take out your punnett square notes sheet . HW : Reproduction Exam Review Sheet Castle Learning due TUESDAY!. Example #3:
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Topic: Genetics Aim: How do we use pedigree charts to follow a trait through generations of a family? Do Now: Take out your punnett square notes sheet. HW: Reproduction Exam Review Sheet Castle Learning due TUESDAY!
Example #3: Red is dominant in flowers & whiteis recessive. Cross a heterozygous flower with a homozygous dominant flower. • R = redr = white • Rr x RR
Rr x RR R r Genotype = R r R R R 50% homozygous dominant R R R R r 50% heterozygous Phenotype= 100% red
One dog carries the heterozygous, black fur trait and the other carries homozygous recessive white traits. What are the chances of having a puppy with black fur? B = black, b = white Bb x bb
B b Bb x bb b b b B b Answer: 50% chance of having a puppy with black fur b B b b b
Humans have 46 chromosomes in EVERY somatic cell in the body. Out the 46 chromosomes, 2 of them are sex chromosomes that determine gender. The other 44 chromosomes are called autosomes.
Sex chromosomes • XY - male • XX - female
Male chromosomes Female chromosomes
How is the sex of an individual determined? • Eggs = X • Sperm = X or Y
The X chromosome carries a couple of thousand genes but few, if any, of these have anything to do directly with sex determination. The X chromosome likely contains genes that provide instructions for making proteins. These proteins perform a variety of different roles in the body.
The Y chromosome likely contains genes that provide instructions for making proteins. The genes on this chromosome tend to be involved in male sex determination and development. Sex is determined by the SRY gene, which is responsible for the development of a fetus into a male. Other genes on the Y chromosome are important for male fertility.
1. What are pedigree charts used for? • To follow a trait through generations of a family
Male withoutthe trait. Male withthe trait. Female withoutthe trait. Female withthe trait. Female and male carriers
Diagonal line = deadfrom inherited condition Marriageline connects people Offspringline going down Offspring(oldest to the left)
Topic: Genetics Aim: How do we use pedigree charts to follow a trait through generations of a family? Do Now: Take out your pedigree chart notes and your punnett square notes sheet. HW: Castle Learning!!!!
One dog carries the heterozygous, black fur trait and the other carries homozygous recessive white traits. What are the chances of having a puppy with black fur? B = black, b = white Bb x bb
B b Bb x bb b b b B b Answer: 50% chance of having a puppy with black fur b B b b b
3. What does the pedigree chart below show? How the British Queen Victoria’s family was affected by a disease called hemophilia. 4. Describe hemophilia. A disease that causes the body to make too little of a certain protein that stops bleeding from damaged blood vessels.
The shape of earlobes is inherited. The letter “E” stands for the gene (allele) for unattached or “free” earlobes. The letter “e” stands for the gene (allele) for attached earlobes. Free earlobes 6. Identify the allele represented by “E.” 7. Identify the allele represented by “e.” Attached earlobes
The shape of earlobes is inherited. The letter “E” stands for the gene (allele) for unattached or “free” earlobes. The letter “e” stands for the gene (allele) for attached earlobes. • 8. James and Yolanda are a married couple. • Identify the kind of earlobes James has. • Identify the kind of earlobes Yolanda has. Attached earlobes Free earlobes
The shape of earlobes is inherited. The letter “E” stands for the gene (allele) for unattached or “free” earlobes. The letter “e” stands for the gene (allele) for attached earlobes. c. How many children do James and Yolanda have? What are their names? d. Identify Tony’s children and the types of earlobes each child has. TWO Tony and Jasmine Andrew - unattached Maria - unattached
The shape of earlobes is inherited. The letter “E” stands for the gene (allele) for unattached or “free” earlobes. The letter “e” stands for the gene (allele) for attached earlobes. e. Identify Jasmine’s children and the types of earlobes each child has. T.J. - unattached Caroline - attached
The shape of earlobes is inherited. The letter “E” stands for the gene (allele) for unattached or “free” earlobes. The letter “e” stands for the gene (allele) for attached earlobes. ee f. Identify Caroline’s genotype. g. Why does Caroline have attached earlobes? Her parents must be heterozygous for the train. (Ee x Ee)
9. Person # 1 is: a carrier for the trait. 10. Identify the difference between #7 and #9. #7 is a carrier and #9 is not. 11. What is the relationship between individuals #1 and #2? #1 and #2 are married. 12. Which statement about individual #3 is true? #3 is married to #4
13. What is the meaning of the line through #4? The person dies from the inherited trait. 14. What is the relationship between #4 and #5? #4 is the sister of #5 15. How is it possible for #9, #10 and #11 to not have the trait? The trait is recessive.
1 2 3 5 9 4 8 6 11 10 12 13 7 • Identify the genotypes of 1 and 2. Heterozygous 2. How many offspring did 1 and 2 have? Six 3. Identify the genotype of 5. Homozygous recessive 22 19 15 16 17 18 25 14 20 23 21 24
heterozygous • Identify the genotype of the father. 2. Identify the genotype of the mother. Homozygous recessive
4 3. How many children did the first generation have? 4. How many children have the trait? 2
1. How many offspring did the first generation have? 4 2. How many offspring from the first generation were born with the trait? None 3. How many females did the first generation have? TWO 4. How many males did the first generation have? TWO
1. How many offspring did the 1st generation have? 3 2. How many offspring from the 1st generation were born with the trait? 1
3. Individual 3 had children with individual 4. a. How many children did 3 and 4 have? 2 b. Which child was born with the trait? male c. What were the genotypes of individuals 3 and 4? heterozygous
T = tall t = short Cross two heterozygous plants. Tt x Tt T t T T T T t T t t t t
T t T Phenotype %: 75% tall 25% short Genotype %: 25% homozygous dominant 50% heterozygous 25% homozygous recessive T T T t T t t t t
G = green g = yellow Cross a pure green plant with a hybrid plant. G G GG X Gg G G G G G G g g G g
G G G G G G G Phenotype percentages: 100% green Genotype percentages: 50% heterozygous 50% homozygous dominant G g g G g