genetics & inheritence. genetics – the study of heredity. heredity – the transmission of...
TRANSCRIPT
![Page 1: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/1.jpg)
GENETICS & INHERITENCE
![Page 2: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/2.jpg)
GENETICS & INHERITENCE
![Page 3: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/3.jpg)
GENETICS & INHERITENCE
![Page 4: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/4.jpg)
GENETICS & INHERITENCE
![Page 5: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/5.jpg)
GENETICS – the study of heredity.
HEREDITY – the transmission of genes from parents to offspring.
![Page 6: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/6.jpg)
Hey genetics… who’s your daddy?
Gregor Mendel – the father of genetics
Austrian monk in the 1840’s
![Page 7: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/7.jpg)
MENDEL’S EXPERIMENTS:
He studied characteristics of garden pea plants.
WHY PEAS?Easy to growProduce many offspringMature very quicklyCould allow:
SELF-FERTILIZATION – reproduction in the same organism.
CROSS-FERTILIZATION – reproduction between two different organisms.
![Page 8: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/8.jpg)
MENDEL’S EXPERIMENTS
STEP 1SELF-FERTILIZED pea plants for many generations until they produced pure-breeding plants.
PURE BREEDING – trait observed in parent plants shows up in offspring of the offspring.AKA true-breeding / pure breedExample: White flowered plants produce only white flowered offspring.
He called these P1 generationP1 GENERATION – parental generation
![Page 9: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/9.jpg)
MENDEL’S EXPERIMENTS
STEP 2Crossed a purple flowered plant from the P1 generation with a white flowered plant from the P1 generation.He called the offspring of those plants the F1 generation
F1 GENERATION – first filial generation; first generation of offspring
All flowers on plants in the F1 generation turned out to be purple
![Page 10: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/10.jpg)
MENDEL’S EXPERIMENTS
STEP 3He allowed the F1 generation plants to self- fertilize
He called this next generation of resulting plants the F2 generation
He notice that white flowers reappeared.
![Page 11: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/11.jpg)
MENDEL’S CONCLUSIONS
1. Traits are controlled by genes
GENE – small segment of DNA on a chromosome that codes for a trait.
![Page 12: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/12.jpg)
MENDEL’S CONCLUSIONS
2. Genes have alternative forms.ALLELE – alternative forms of a gene
Every individual has 2 alleles for each trait
One from momOne from dad
Example:Purple flowers = PWhite flowers = p
![Page 13: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/13.jpg)
MENDEL’S CONCLUSIONS
3. Alleles can be dominant or recessive
Dominant alleles are always expressed
Recessive alleles can be masked by Dominant ones.
Recessive alleles are expressed only when there are two copies
EXAMPLES:
T- tall TT - tall
t – short Tt – tall
tt – short
![Page 14: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/14.jpg)
MENDEL’S CONCLUSIONS
4. An individual is said to be Homozygous if both of its alleles are the same.
TT or tt
DD or dd
5. An individual is said to be Heterozygous if its alleles are different.
Aa Tt
Bb Dd
![Page 15: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/15.jpg)
MENDEL’S CONCLUSIONS6. LAW OF SEGREGATION - alleles are separated
during the formation of gametes (sex cells—sperm or egg). A gamete can only have ONE allele or THE OTHER
T = Tall
t = short
If a plant has Tt, gametes can either have a T or t in them
If a plant has TT, gametes can only have T in them
If a plant is tt, gametes can only have a t in them
**Remember—letters represent forms of a gene!
![Page 16: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/16.jpg)
MENDEL’S CONCLUSIONS
7. LAW OF INDEPENDENT ASSORTMENT - alleles for different characteristics are distributed to gametes independently.
EXAMPLE: Just because you have one dominant trait (Ex: Brown eyes), does not mean that you have ALL dominant traits.
![Page 17: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/17.jpg)
PUNNETT SQUARESDiagrams used for:
Predicting the result of a cross.Determining the probability of a certain result.
PROBABILITY – the likelihood that something will happen (it is not definite)
Example: Flipping CoinsWhat is the probability of HEADS? 1/2What is the probability of TAILS? 1/2What is the probability of 2 HEADS in a row
1/2 x 1/2 = 1/4Each flip is an independent eventPrevious outcomes DON’T affect future outcomes
![Page 18: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/18.jpg)
MORE VOCAB
Genotype – Refers to the genetic makeup of a specific set of genes
Phenotype – refers to the physical characteristics or traits of an individual.
![Page 19: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/19.jpg)
Essential VOCAB:
DOMINANT
RECESSIVE
HOMOZYGOUS
HETEROZYGOUS
YOU MUST KNOW THESE WORDS TO BE SUCCESSFUL FOR THE
REMAINDER OF THIS CHAPTER: Pop Quiz soon…
![Page 20: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/20.jpg)
Pop Quiz:
1. Phenotype
2. Genotype
3. Heterozygous
4. Homozygous
5. Dominant
6. Recessive
7. Gene
8. Allele
1. Small section of DNA coding for a protein
2. Genetic makeup; ex. Tt
3. Gene that is masked by another; represented by a lower case letter; ex. t
4. Gene that covers up or masks another gene; represented by a capital letter; ex T
5. Two identical forms of a gene: ex TT or tt
6. Two different forms of a gene: Tt
7. Physical appearance of expression of a gene; ex. Brown eyes
8. Different forms of a gene; ex red or white flowers
![Page 21: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/21.jpg)
Pop Quiz:
1. Phenotype
2. Genotype
3. Heterozygous
4. Homozygous
5. Dominant
6. Recessive
7. Gene
8. Allele
1. Small section of DNA coding for a protein
2. Genetic makeup; ex. Tt
3. Gene that is masked by another; represented by a lower case letter; ex. t
4. Gene that covers up or masks another gene; represented by a capital letter; ex T
5. Two identical forms of a gene: ex TT or tt
6. Two different forms of a gene: Tt
7. Physical appearance of expression of a gene; ex. Brown eyes
8. Different forms of a gene; ex red or white flowers
![Page 22: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/22.jpg)
Incomplete Dominance and Co-Dominance
![Page 23: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/23.jpg)
Incomplete Dominance
• Neither allele is dominant over the other.
• Heterozygous individuals have a phenotype that is in between the homozygous individuals
• Don’t use CAPS and lower case b/c neither is DOM/rec*
• Example: Blue and Red (B and R, or B and B´) BR=purple
![Page 24: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/24.jpg)
SnapdragonsIn snapdragons, flower color can be red, pink, or white. The heterozygous condition results in pink flowers
WW RWRR
![Page 25: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/25.jpg)
![Page 26: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/26.jpg)
![Page 27: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/27.jpg)
Hair texture can follow the incomplete dominance pattern.Curly: _______________Straight: _______________Wavy: _______________Cross wavy with wavy_______________ X _______________
Complete a Punnett Square
![Page 28: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/28.jpg)
Co-dominanceBoth alleles are expressed equally
Neither allele is recessive
Both expressed as if they are a mixed dominance.
Erminette chickens
Roan Cows/Horses
![Page 29: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/29.jpg)
Co-Dominance Erminette Chicken
P generation
Black chicken X White chicken
F1 generation = erminette (checkered patterned)
Key:B =BlackB1 (or W)=White
B B
B1
B1
B
BB
B B1
B1
B1
B1
Phenotype: 4:0 or 1:0100% erminette
Genotype: 4:0 or 1:0100% heterozygous
![Page 30: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/30.jpg)
Multiple Alleles
• So far every trait has had only 2 variations (like tall or short)
• Some traits have more than two versions
ex. Blood types, coat color in rabbits
• Individuals still have only 2 alleles (1 from mom, 1 from dad), there are just more choices available
• Hierarchy of dominance (one is most dominant, another is second most dominant, etc.)
![Page 31: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/31.jpg)
What other genotypes could result in Chinchilla fur?
![Page 32: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/32.jpg)
Multiple Alleles
C= full color Dominant to all other alleles
cch = Chinchilla recessive to C dominant to c
ch = Himalayan recessive to both C and cch. Dominant to c allele
c= albino, no color recessive to all other alleles.
C > cch > ch > c
Dominant Recessive
![Page 33: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/33.jpg)
What’s your type?
![Page 34: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/34.jpg)
Blood Type Percentages
Data from CDC 2002
![Page 35: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/35.jpg)
in
![Page 36: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/36.jpg)
Codominance AND Multiple Alleles: Blood Types
Blood type refers to the antigens on the surface of your red blood cells. You can have 2 different antigens (___ or ___), or none. (3 choices=multiple alleles)
Antigens A and B are both seen when present. Neither is dominant over the other and there is no mixture or blending of phenotypes. (______________________)
![Page 37: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/37.jpg)
Blood Type Inheritance
Key can change:
Dominant: I with superscript A or B or just A and B (for A or B antigens, respectively)
Recessive: i or O (for no antigens)
![Page 38: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/38.jpg)
Blood type
Cross a male type A with a female type AB.
Complete 2 Punnett Squares (the father has two possible genotypes).
Cross 1: _____X_____
Cross 2: _____X_____
Analyze the possible offspring phenotypes and genotypes for each cross.
![Page 39: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/39.jpg)
Richardson is of mixed race, with Nigerian and English heritage, while the father is white. A genetics expert at Oxford University says such births are rare, as the genes that cause skin color normally mix together. In this case, he says, it appears the genes for skin color didn't combine for some reason and the boys may have inherited different genetic codes from their mother.
AP updated 7:15 p.m. ET, Fri., Oct . 27, 2006
LONDON - A pair of British twin boys has been born with different skin color, a rare genetic occurrence according to experts.In an interview with Britain's Sky News program, mother Kerry Richardson said that the boys were both born white but as they've gotten older one of the boys got darker and the other lighter.Today, she says, the twins attract attention wherever they go.
![Page 40: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/40.jpg)
Polygenic traits--Traits that are controlled by more than 1 gene.-Example—there are at least 4 different genes that code for skin color.-Multiple genes controlling a single trait produce a wide variety of phenotypes
![Page 41: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/41.jpg)
Which karyotype is from a male? Female?Which symbol represents male? Female?
A B
![Page 42: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/42.jpg)
Sex ChromosomesSex chromosomes determine gender.
X and Y chromosomes both contain genes to develop into a male or a female.
There are other genes found on the sex chromosomes… we call those sex-linked traits.
X X X Y
![Page 43: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/43.jpg)
The Classic Baldness in Males
![Page 44: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/44.jpg)
What they try to do to cover it up!
![Page 45: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/45.jpg)
What they should do.
![Page 46: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/46.jpg)
Sex linked traits
XB Xb
Xb XBXb
XbXb
Y XBY XbY
B = normal hairb = baldness
XBXb x XbY
½ females normal½ females carrier ½ males normal½ males bald
![Page 47: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/47.jpg)
Hemophilia H = normal bloodh = hemophilia
XH Xh
XH XHXH XHXh
Y XHY XhY
XHXh x XHY
2/2 females normal½ males normal½ males hemophilia
![Page 48: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/48.jpg)
Think!
So, where do sons get sex-linked, recessive traits from?
Why is it more common to have males with hemophilia (or any other sex linked gene) than females?
![Page 49: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/49.jpg)
A Little Info on Hemophilia•Hemophilia occurs when a factor (protein) in the blood is missing.
•The factor is needed to clot blood.
•Hemophiliacs bruise very, very, easily.
![Page 50: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/50.jpg)
![Page 51: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/51.jpg)
Most common is red/green colorblindness.
What number do you see to the right?
![Page 52: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/52.jpg)
Color blindness
![Page 53: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/53.jpg)
![Page 54: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/54.jpg)
CALICO CATS… another sex-linked trait
![Page 55: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/55.jpg)
Let’s see what you’ve learned!
In cats there is a gene for coat color, which is codominant and sex linked. There is one gene for brown and one gene for black. The heterozygote has a coat that is brown and black which is called tortoise-shell or calico.
Cross a black female with a brown male.
![Page 56: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/56.jpg)
Need some help?
BB-black
WW-brown
BW- tortoise or black & brown
XBXB x XWY
![Page 57: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/57.jpg)
XB XB
XW XBXW XBXW
Y XBY XBY
Two female tortoise-shell and two black males.
•Only females can express both colors at the same time according to the Punnett Square. •Can male cats ever be calicos or tortoise?
•Hint: Think back to meiosis and how Down Syndrome occurs.
![Page 58: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/58.jpg)
Another one…. Ear hair in older men!
![Page 59: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/59.jpg)
![Page 60: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/60.jpg)
![Page 61: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/61.jpg)
![Page 62: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/62.jpg)
![Page 63: GENETICS & INHERITENCE. GENETICS – the study of heredity. HEREDITY – the transmission of genes from parents to offspring](https://reader035.vdocuments.net/reader035/viewer/2022062305/5697bfdb1a28abf838cb054b/html5/thumbnails/63.jpg)
Albino people occur approximately 1 in 17,000. Most have serious eye problems.