Download presentation
Presentation is loading. Please wait.
Published byBryan Wilkins Modified over 8 years ago
1
Unit 12 - Heredity
3
father of genetics
4
Austria Italy Gregor Mendel Germany Poland Austria Czech Republic was born in 1822 in Heinzendorf, Austria, to a peasant farming family.
5
When he was 21, one of Mendel’s teachers took note of his exceptionally bright mind and persuaded him to join the Augustinian monks. St.Thomas Church, (now Brno, Czechoslovakia)
6
Rather than study every characteristic of the garden pea, Mendel narrowed his observations to 7 traits For 8 years, Mendel experimented with over 28,000 peas in the large gardens attached to the monastery. Mendel conducted numerous experiments on plants. Mendel narrowed his focus to one particular type of garden pea.
7
Garden Pea Traits Observed
8
Seed shape Seed color Pod shape Flower color Flower location Plant size smooth wrinkled yellow green smooth bumpy green yellow Pod color purple white Along stem at tip tall short
9
In 1866 when Mendel was 44, his experimental results were published... and ignored long after he died.
10
In 1900, 3 scientists - Carl Correns, Hugo de Vries, and Erich von Tschermak - all independently rediscovered and verified Mendel's principles, marking the beginning of modern genetics. He is now considered the father of genetics.
11
Genetics & Heredity Heredity-The passing of characteristics from parents to offspring Genetics -The branch of biology that focuses on heredity
12
Are these inherited traits? Your eye color Your hair color and texture Your height
13
Are these inherited traits? Your personality Your musical, athletic, and artistic abilities
14
Think about this…. My parents have brown eyes, why are mine blue?” “My brother is tall. Why am I short?” “Why does my sister have blonde hair while mine is brown?”
15
Mendel’s studies led to… Alleles- the different versions of a gene (an individual receives one allele from each parent)
16
Mendel’s studies led to… Dominant- the expressed form of the trait ex. H Recessive- the trait that is not expressed if a dominant allele is present ex. h
17
Mendel’s studies led to… Genotype- the genetic makeup of an organism (the set of alleles an individual has) ex: Ff or FF Phenotype- the physical appearance of an organism ex. has freckles
18
Mendel’s studies led to… Homozygous- the two alleles present for a characteristic are the same Ex: hh or HH Heterozygous- the two alleles present for a characteristic are different Ex: Hh
19
Tongue Roller R = Tongue Roller r = Unable to Roll Tongue
20
Widow’s Peak W = Widows Peak w = Lack of Widow’s Peak
21
Free Ear Lobe Attached Ear Lobe E = Free Ear Lobe e = Attached Ear Lobe
22
Hitchhiker’s Thumb H = Straight Thumb h = Hitchhiker’s Thumb
23
Bent Little Finger B = Bent Little Finger b = Straight Little Finger
24
Mid-digital Hair M = Mid-Digital Hair m = Absence of Mid-Digital Hair
25
Dimples D = Dimples d = Absence of Dimples
26
Short Hallux H = Short Hallux h = Long Hallux
27
Short Index Finger S = Short Index Finger s = Long Index Finger
28
The Theory of Heredity Inherited allele for purple P HOMOZYGOUS purple flower (PP)
29
The Theory of Heredity Inherited allele for purple P for pink flower (p) HETEROZYGOUS purple flower (Pp)
30
The Theory of Heredity Inherited allele for pink flower (p) HOMOZYGOUS pink flower (pp)
31
PREDICTING HEREDITY
32
Probability The likelihood that a specific event will occur Probability = # of 1 kind of possible outcome Total number of possible outcomes Example: What is the probability that a tossed coin will be heads? ½ or 50%
33
Probability What is the probability that a couple will have four boys? ½ x ½ x ½ x ½ = 1/16 What is the probability you will win the lottery? 6/50 x 5/49 x 4/48 x 3/47 x 2/46 x 1/45…
34
Aa x Aa Monohybrid Cross: a cross that shows the possible offspring for one trait Aa A a AA Aa aa Genotypic Ratio: 1:2:1Phenotype: 3 white:1 brown A: White fur a: Brown fur
35
*genotypic ratio: *phenotypic ratio: *What is the probability of having smooth-nosed offspring? *What is the probability of having two smooth-nosed offspring? Dragons have either smooth or wrinkled noses. Wrinkled is dominant over smooth. If a smooth-nosed female dragon is crossed with a heterozygous wrinkle-nosed male, how many of their offspring are likely to have smooth noses? __ _ _
36
Fur Color:Coat Texture: B: Black R: Rough b: White r: Smooth BbRr x BbRr Dihybrid Cross: a cross that shows the possible offspring for two traits
37
BbRr x BbRr First, you must find ALL possible gametes that can be made from each parent. Remember, each gamete must have one B and one R. Dihybrid Cross:
38
Dihybrid Crosses: a cross that shows the possible offspring for two traits Fur Color: B: Black b: White Coat Texture: R: Rough r: Smooth BbRr x BbRr BR bR br bR Br BR br Br BBRRBbRRBbRr BBRrBBrrBbRrBbrr BbRRBbRrbbRRbbRr BbRrBbrrbbRrbbrr BBRr Phenotypic Ratio: 9:3:3:1
39
Dihybrid Crosses: a cross that shows the possible offspring for two traits BR bR br bR Br BR br Br BBRRBbRRBbRr BBRrBBrrBbRrBbrr BbRRBbRrbbRRbbRr BbRrBbrrbbRrbbrr BBRr How many of the offspring would have black, rough coat? How many of the offspring would have a white, smooth coat? How many of the offspring would have a white, rough coat? 16 1
40
More Complex Patterns of Heredity –Codominance –Multiple Alleles –Sex-Linked Traits 16 1
41
Codominance: two dominant alleles are expressed at the same time 16 1 CRCRCRCR CWCWCWCW CRCWCRCW
42
Codominance 16 1 Sickle-Cell Anemia is another codominant trait. NANA NANA NSNS NANA NSNANSNA NSNANSNA NANANANA NANANANA N A =Normal RBC N S =Sickle Cell RBC
43
Pedigree Analysis
44
Pedigree Used to show genetic inheritance over generations in a family
45
Pedigree Example male female Female Carrier Marriage Offspring
46
Royal Family Hemophilia People affected by the disease People who are “carriers” for the disease, but do not have symptoms—can pass on to children
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.