CHAPTER 5 “HEREDITY” P. 126.
-
Upload
rachel-mccarthy -
Category
Documents
-
view
238 -
download
5
Transcript of CHAPTER 5 “HEREDITY” P. 126.
![Page 1: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/1.jpg)
CHAPTER 5 “HEREDITY“HEREDITY”
P. 126
![Page 2: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/2.jpg)
Chapter Five “I Cans” Heredity
1. I can draw a Punnett Square and determine the possible
outcomes of the crosses.
2. By using a pedigree, I can track a trait over several generations.
3. I can distinguish between genotypes / phenotypes and
heterozygous / homozygous traits.
4. I can identify dominant and recessive traits and use a Punnett
Square to identify the possible traits of the offspring.
![Page 3: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/3.jpg)
Heredity- is the passing of traits from parent to offspring.
Genetics- the study of how traits are inherited through the action of alleles.- are different forms of the same trait
![Page 4: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/4.jpg)
If the trait is If the trait is hair colorhair color,,
- are possible alleles.
blonde
brunette
red
![Page 5: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/5.jpg)
If the trait is If the trait is eye color,eye color,
- are possible alleles.
blue
brown
hazel
![Page 6: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/6.jpg)
Genetics was ‘started’ by Gregor Mendel.- he experimented
with pea plant traits in the 1800’s.
- is considered the ‘father’ of genetics. (p. 127 -128)
![Page 7: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/7.jpg)
![Page 8: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/8.jpg)
Purebred- an organism that
always produces the same traits in its offspring.Ex. St. Bernards produce St. Bernards
Ex. Siamese cats produce Siamese kittens
![Page 9: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/9.jpg)
Mendel “crossed” traits and discovered that some traits appear more often.
- called dominant
Ex. Brown eyes over blue eyes.Ex. Tall pea plants over short plants.
![Page 10: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/10.jpg)
The dominant trait “masks” the hidden trait:
Ex. Blue eyesEx. Red hairEx. Attached ear lobes
- called recessive.
![Page 11: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/11.jpg)
![Page 12: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/12.jpg)
Mendel then allowed the “crossed” tall and short plants to reproduce.
- surprising results.- out of 4 plants =
3 tall / 1 short(because the tall
were dominant)- always got a 3:1
ratio.
![Page 13: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/13.jpg)
What is the ratio of girls to boys in your row?
What is the ratio of plants to people in this room?
![Page 14: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/14.jpg)
Because of ratios, Mendel could create probabilities of what the offspring would be.- he could predict which
traits would appear.Ex. The offspring of the
tall and short plant cross75% chance of tall25% chance of short Coin
FlipProbability = 50% heads / 50% tails Ratio = 1:1
![Page 15: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/15.jpg)
PUNNETT SQUARES
Purebred tall and purebred short cross= All Tall offspring
T T
t tTt TtTt Tt
The crossed offspring produce
3 talls and 1 short
![Page 16: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/16.jpg)
Ratio? Probability? 4:0100% tall 0% short
T T
t tTt TtTt Tt
Tt is a hybrid - or mix.
Notice the 3:1 ratio
![Page 17: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/17.jpg)
Ratio of short to tall?
1:3Probability of
having tall offspring?
75%Probability of
having short offspring?
25%
![Page 18: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/18.jpg)
![Page 19: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/19.jpg)
A punnett square shows the genotype of an organism.
- actual genetic traits (can’t see)
Ex. Bb, TT. -the alleles.
B bBb
BB Bb
Bb bb
![Page 20: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/20.jpg)
phenotype - the visible traits. (can see or touch)
Hazel eyes
Attached ear lobes
![Page 21: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/21.jpg)
![Page 22: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/22.jpg)
If the alleles are the same (BB or tt)- they are called homozygous.
If the alleles are different (Bb or Tt)- they are called heterozygous.
(or purebred) (or hybrid)
(for animals only!)
![Page 23: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/23.jpg)
ASSIGNMENT:WORKSHEET
“WHAT IS GENETICS?P. 132 SELF CHECK
1 - 4 (ON BACK)
![Page 24: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/24.jpg)
Incomplete dominance - when one trait is not dominant over another.
Ex. four o’clock flowers
RR = redrr = white
R R
rr
Rr RrRr Rr
Results:
4 Pink! (Rr)Ratio:
Red:white:pink 0:0:4
![Page 25: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/25.jpg)
Ratio: red/pink/white1:2:1
R r
Rr
RR RrRr rr
Results:1 red, (RR)2 pink, (Rr)1 white (rr)
Probability of a red flower?25%
Probability of a pink flower?50%Probability of a white flower?
25%
![Page 26: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/26.jpg)
Ratio: red/pink/white2:2:0
R R
Rr
RR RRRr Rr
Results:2 red, (RR)2 pink, (Rr)0 white (rr)
Probability of a red flower?50%
Probability of a pink flower?50%Probability of a white flower?
0%
![Page 27: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/27.jpg)
Polygenic inheritance - when a group of genes -not just two -combine to form a trait.
Ex. blood type, eye color, skin color, height, etc.
![Page 28: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/28.jpg)
Codominance- a phenotype that is blended or
“mixed”
![Page 29: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/29.jpg)
![Page 30: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/30.jpg)
Sex Determination- the male determines the sex of the
offspring.XX = female (two X chromosomes)XY = male (one X, one Y chromosome)
![Page 31: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/31.jpg)
Probability of having a girl?
50%Probabilty of having
a boy?50%Ratio of boys to girls?2:2 or 1:1
X X
XY
XX XX
XY XY
![Page 32: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/32.jpg)
WORKSHEET
“PUNNETT SQUARES”
![Page 33: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/33.jpg)
Sex-linked Disorders- inherited “conditions”
linked to the X chromosome.Ex. color blindness, hemophilia.
- these disorders are carried on the females’ X chromosome.
(the female is a carrier)
![Page 34: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/34.jpg)
![Page 35: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/35.jpg)
Results:XX - 1 normal girlXY - 1 normal
boyXXc - 1 carrier girlXcY - 1 colorblind boy
X Xc
XY
XX XXc
XY XcY
For a girl to be colorblind, the trait must appear on both alleles. (XcXc)
![Page 36: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/36.jpg)
Colorblind TestsColorblind Tests
![Page 37: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/37.jpg)
How a colorblind person would see a strawberry plant:
![Page 38: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/38.jpg)
Hemophilia - a disease where the blood will not clot. It was common in the royal families of Europe.
![Page 39: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/39.jpg)
Hemophilia Results:XXh =
two carrier femalesXY =
two normal malesXh
Y
X XXXh
XYXXh
XYProbability of having a hemophilic child?
0%
Probability of having a female carrier?
100%
![Page 40: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/40.jpg)
Hemophilia Ratio of carrier females to normal males?
2:2or 1:1Xh
Y
X XXXh
XYXXh
XYProbability of having a hemophilic female?
0%
Probability of having a normal male?
100%
![Page 41: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/41.jpg)
Hemophilia Results:XXh
= carrier femaleXY
= unaffected maleXhXh
= hemophilic femaleXhY
= hemophilic male
Xh
Y
X XhXXh
XYXhXh
XhY
Probability of having a hemophilic child?
50%
![Page 42: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/42.jpg)
- a record of an organism’s ancestors.- it traces the occurrences of a trait.
(p. 139 in text)
Pedigree
![Page 43: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/43.jpg)
Results:1 normal male1 normal female1 carrier female1 affected male
PedigreeIs the pedigree correct?
Do the punnett!
X XhX
YXXXY
XXh
XhY
![Page 44: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/44.jpg)
The Symbols of a Pedigree:
Read pp. 137 - 138. “Human Genes and Mutations”.
?!!
Female (normal)Male (normal)Female with traitMale with trait
Female carrierMale carrier
![Page 45: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/45.jpg)
ASSIGNMENT:WORKSHEET“GENETICS”
![Page 46: CHAPTER 5 “HEREDITY” P. 126.](https://reader034.fdocuments.us/reader034/viewer/2022051318/5a4d1ad07f8b9ab059970ffd/html5/thumbnails/46.jpg)
Chapter Five “I Cans” Heredity
1. I can draw a Punnett Square and determine the possible
outcomes of the crosses.
2. By using a pedigree, I can track a trait over several generations.
3. I can distinguish between genotypes / phenotypes and
heterozygous / homozygous traits.
4. I can identify dominant and recessive traits and use a Punnett
Square to identify the possible traits of the offspring.