Download presentation
Presentation is loading. Please wait.
Published byTyrone Tyler Modified over 9 years ago
1
Chapter 4: Heredity Section1- Genetics Life Science Lesson Plan
2
Inheriting Traits Create a short list of characteristics about yourself… What is another name for these characteristics? TRAITS
3
Heredity Heredity is the passing of traits from parents to offspring. Inherited Traits- Traits that are passed from parents to their offspring (through fertilization)
4
Genes are passed… but what are genes? Genes are sections of DNA on a chromosome. These genes on chromosomes control the traits that show up in an organism. –There are thousands of genes on a chromosome
5
Alleles are different forms of a trait that a gene may contain. –There are 2 alleles for each gene –1 from mom and 1 from dad Example: Height –1 allele is tall –1 allele is small
6
Alleles alleles a gene
7
B. Genetics- is the study of inherited traits. 1. Gregor Mendel- The Father of Genetics “The Man”
9
Mendel’s Experiment Mendel studied the traits of Pea Plants –Look Page 105 Crossed 2 Plants with different expressions of the trait –Example- Tall (T)& Short (t) –Round R & Wrinkled r
10
Mendel’s Experiment When the plants were crossed he discovered that the new plant formed looked like one of the two parents. Take a look… Mendel’s Tall vs. Short Plants
11
VOCABULARY 3. Purebreds- offspring receives the two same alleles for a trait (TT or tt)
12
VOCABULARY 4. Hybrids- offspring receives two different alleles for a trait (Tt)
13
2 Types of Alleles a.Dominant allele- covers up or dominates the other trait Represented by a Capital Letter b. Recessive allele- the trait seems to disappear Represented by a lower-case letter
14
“Homo”zygous – an organism with 2 alleles for one trait that are the same (written TT) “Hetero”zygous – an organism with 2 alleles for one trait that are different (written Tt)
15
Genotype- the genetic- makeup of an organism (types of letters used)
16
Phenotype- the way an organism physically looks/behaves as a result of its genotype. Types of Words used: Tall, Short, Blonde, Brown, etc.
17
The Use of Punnett Squares A Punnett Square can help you predict what an offspring will look like. “What’s the Probability of the baby’s gender?”
18
A Punnett Square can help you predict what an offspring will look like 1. Monohybrid: Offspring of parents that differ in only one genetic characteristic
19
Monohybrid Cross: GG x gg
20
DYHIBRID CROSSES 2. Dyhybrid: Offspring of parents that differ in TWO genetic characteristic ***USE FOIL to separate the combinations F – FIRST O – OUTSIDE I – INSIDE L – LAST
21
DIHYBRID EXAMPLE Tall & Green TtGg x TtGg
22
DIHYBRID EXAMPLE #2 Brown hair vs Blonde hair AaBb x aaBb
24
Chapter 4 Part 2- Genetics Since Mendel Life Science
25
Question… If you crossed Purebred Red four- o’clock flower with Purebred White four-o’clock flower, what would the offspring look like?
26
Actually… they were PINK!?!?!
27
Incomplete Dominance- when two homozygous parents combine, the offspring results in a blended phenotype Combining Purebred Red & White and produced Pink
28
Neither allele for a trait is Dominant. The phenotype produced is mixed between the two homozygous parents. –The combining of Purebred Red & Purebred White produced PINK plants.
29
What would happen if you crossed a Red horse and a White horse?
30
PINK!?!?!
31
Just kidding… ROAN
32
Although Mendel studied peas that were controlled by two alleles, many traits can be controlled by more than two alleles…
33
Multiple Alleles A trait that is controlled by Having more than two alleles is controlled by Multiple Alleles. Traits controlled by Multiple Alleles produce more than three phenotypes of that trait.
34
Example (Flip to Page) Example of Multiple Alleles… Blood Types: A, B, AB, and O. –The O allele is recessive to both A and B
35
Other Worksheet… Phenotype A - AA or AO Genotype Phenotype B – BB or BO Genotype Phenotype AB – AB Genotype Phenotype O – OO Genotype
37
Polygenic Inheritance Polygenic Inheritance- when a group of gene pairs acts together to produce one trait. –Which creates more variety in phenotypes
38
What would be an example? Many traits such as…Skin Color, Eye Color, Hair Color, and Handspan are traits produced by a combination of genes.
39
Human Genes & Mutations Mutations : a permanent change in the DNA sequence A mutation can be helpful, harmful, or cause no effect.
49
Mutations Chromosome disorders- caused by more or fewer chromosomes than normal Downs Syndrome- caused by an extra copy of chromosome 21
50
Recessive Genetic Disorders There are human genetic disorders that are caused by Recessive Genes. How could this occur? Both parents contain the recessive allele
51
Because parents are Heterozygous, they do not show any symptoms –(Called “carriers” for the trait.) Cystic Fibrosis is a homozygous recessive disorder.
52
Sex-Linked Disorders An allele inherited on a sex chromosomes ( X or Y ) is called a sex-linked gene. Inherited conditions are linked with the X and Y chromosomes.
53
Example- Color Blindness is a sex- linked disorder caused by recessive allele on the X chromosome.
56
Where did you get your genes from?
57
Pedigrees Pedigree- used to follow or trace traits through generations of a family.
58
No… not the dog food…
59
Section 3 III. Advances in Genetics A. Genetic Engineering- experimentations that changes the arrangement of DNA that makes up a gene.
60
Types: 1. Recombinant DNA Inserting a useful section of DNA into a bacteria Example- Creating Insulin (Page 143)
61
2. Gene Therapy- When a “normal allele” is placed into a virus, the virus then delivers the normal allele when it infects a specific cell. (Figure 13 Page 144) May be used to control Cystic Fibrosis and other disorders.
62
3. Genetically Engineering Plants- Plants are created by genetically inserting the desired genes of one plant into another plant you want to show those genes. Also genetically engineered: ANIMALS “Cloning”
63
Works Cited www.coolclips.com www.coolclips.com http://kentsimmons.uwinnipeg.ca/cm15 04/mendel.htm http://kentsimmons.uwinnipeg.ca/cm15 04/mendel.htm www.classzone.com www.classzone.com www.dkimages.com www.dkimages.com www.virtualsciencefair.org www.virtualsciencefair.org www.scienceray.com
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.