Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in...
-
Upload
roy-rogers -
Category
Documents
-
view
232 -
download
1
description
Transcript of Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in...
![Page 1: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/1.jpg)
Introduction to Genetics
![Page 2: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/2.jpg)
![Page 3: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/3.jpg)
How are traits passed from parent to offspring?
• Traits– Traits are physical
or physiological characteristics of an organism
– Ex. Height or blood type
– Picky Eater????
![Page 4: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/4.jpg)
How are traits passed from parent to offspring?
• Traits– The term
phenotype is used to describe the physical expression of the trait
– Ex. Short/tall or Type A/Type B
![Page 5: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/5.jpg)
Chemical basis of traits• DNA is the
molecule that contains the information to make proteins, which control our traits
![Page 6: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/6.jpg)
Chemical basis of traits• A section of DNA
that is used to make a protein is called a gene.
• There are many genes (hundreds) on a single chromosome.
![Page 7: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/7.jpg)
Fill It In …How are the following terms related? gene, DNA, chromosome
![Page 8: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/8.jpg)
Chemical basis of traits• Eukaryotic organism’s
chromosomes exist in pairs.
• One is inherited from the sperm and one is inherited from the egg.
• Each chromosome, in a pair, contains genes for the same traits.
• This is why we call them homologous pairs.
![Page 9: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/9.jpg)
Chemical basis of traits• Although the genes on
homologous chromosomes may code for the same trait, slight differences in the DNA sequences may lead to different forms of the protein.
![Page 10: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/10.jpg)
Chemical basis of traits• This creates slightly
different versions of the same trait.
• Each version is called an allele.– Ex. Blue and brown
are two alleles of the eye color trait.
![Page 11: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/11.jpg)
Fill It In …• Draw a homologous pair of
chromosomes showing a different allele for eye color on each:
![Page 12: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/12.jpg)
Chemical basis of traits• Genotype is the term
used to describe the combination of alleles present in an organism’s chromosomes.
• An allele is usually represented by a single letter.
• Thus a genotype is usually represented by two letters.
![Page 13: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/13.jpg)
Chemical basis of traits• If an individual inherits
identical copies from each parent the individual is considered homozygous (pure breeding)– Ex. AA or aa
• If an individual inherits a different copy from each parent the individual is considered heterozygous (hybrid)– Ex. Aa
![Page 14: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/14.jpg)
Fill It In …WORD HELP:Pheno - ________________
Geno - _________________
Homo - _________________
Hetero - _________________
![Page 15: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/15.jpg)
Check Yourself!1. Give an example (not in the notes) of a human
trait.
2. What is a phenotype?
3. From where did you get each of the chromosomes in the homologous pair?
4. What is an allele?
5. What is a genotype?
![Page 16: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/16.jpg)
Check Yourself!1. Give an example (not in the notes) of a human
trait. ANSWERS WILL VARY
2. What is a phenotype?
3. From where did you get each of the chromosomes in the homologous pair?
4. What is an allele?
5. What is a genotype?
![Page 17: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/17.jpg)
Check Yourself!1. Give an example (not in the notes) of a human
trait. ANSWERS WILL VARY
2. What is a phenotype? PHYSICAL EXPRESSION OF A TRAIT
3. From where did you get each of the chromosomes in the homologous pair?
4. What is an allele?
5. What is a genotype?
![Page 18: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/18.jpg)
Check Yourself!1. Give an example (not in the notes) of a human
trait. ANSWERS WILL VARY
2. What is a phenotype? PHYSICAL EXPRESSION OF A TRAIT
3. From where did you get each of the chromosomes in the homologous pair? ONE FROM MOM AND ONE FROM DAD
4. What is an allele?
5. What is a genotype?
![Page 19: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/19.jpg)
Check Yourself!1. Give an example (not in the notes) of a human
trait. ANSWERS WILL VARY
2. What is a phenotype? PHYSICAL EXPRESSION OF A TRAIT
3. From where did you get each of the chromosomes in the homologous pair? ONE FROM MOM AND ONE FROM DAD
4. What is an allele? DIFFERENT VERSIONS OF A PARTICULAR TRAIT
5. What is a genotype?
![Page 20: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/20.jpg)
Check Yourself!1. Give an example (not in the notes) of a human
trait. ANSWERS WILL VARY
2. What is a phenotype? PHYSICAL EXPRESSION OF A TRAIT
3. From where did you get each of the chromosomes in the homologous pair? ONE FROM MOM AND ONE FROM DAD
4. What is an allele? DIFFERENT VERSIONS OF A PARTICULAR TRAIT
5. What is a genotype? COMBINATION OF ALLELES FOR AN ORGANISM
![Page 21: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/21.jpg)
How was the path of inheritance discovered …
• in a garden in Austria?• Gregor Mendel
– The father of genetics• Using pea plants, Mendel
proved experimentally the link between meiosis, genes, and inheritance (long before we knew about DNA!)
• He developed 3 basic conclusions:
![Page 22: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/22.jpg)
The Principle of Dominance
• Certain alleles (forms of a trait) can hide/mask other alleles.
• These alleles are called dominant alleles and are represented by a capital letter (A).
• The alleles that may be hidden are called recessive alleles and are represented by the lower case of the same letter (a)
![Page 23: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/23.jpg)
The Principle of Dominance
• Thus, homozygous dominant is AA and will express the dominant phenotype.
• Heterozygous individuals are Aa and will also express the dominant phenotype.
• Only homozygous recessive (aa). individuals will express the recessive phenotype
![Page 24: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/24.jpg)
Fill It In …Draw a picture of a dominant and recessive
trait. Write the possible genotypes under each:
![Page 25: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/25.jpg)
The Principle of Segregation
• Alleles are not passed in pairs from one parent to an offspring.
• Each parent only donates half of each offspring’s genotype (typically one allele per trait).
![Page 26: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/26.jpg)
The Principle of Segregation
• This is because during meiosis only one of each homologous pair of chromosomes is passed to the gamete (sperm or egg)
![Page 27: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/27.jpg)
Fill It In …Based on the parent cell:
What are the possible gametes (after segregation in meiosis)?
A a
![Page 28: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/28.jpg)
The Principle of Independent Assortment• The way one pair
of chromosomes is separated during meiosis does not affect the way the next pair separates.
![Page 29: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/29.jpg)
The Principle of Independent Assortment
• A gene for one trait is only passed in connection with a gene for a different trait if the two genes are on the same chromosome.
• Genes on separate chromosomes are passed independently of each other.
![Page 30: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/30.jpg)
Fill It In …Mendel’s Three Laws:
1. D_______________
2. S_______________
3. I_______________ A_______________
![Page 31: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/31.jpg)
Check Yourself!1. Name Mendel’s three principles of heredity:
2. What cell process allows the principle of segregation to take place?
3. When would a gene for one trait be passed with a gene for a different trait?
![Page 32: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/32.jpg)
Check Yourself!1. Name Mendel’s three principles of heredity:
PRINCIPLE OF DOMINANCE PRINCIPLE OF SEGREGATION PRINCIPLE OF INDEPENDENT ASSORTMENT
2. What cell process allows the principle of segregation to take place?
3. When would a gene for one trait be passed with a gene for a different trait?
![Page 33: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/33.jpg)
Check Yourself!1. Name Mendel’s three principles of heredity:
PRINCIPLE OF DOMINANCE PRINCIPLE OF SEGREGATION PRINCIPLE OF INDEPENDENT ASSORTMENT
2. What cell process allows the principle of segregation to take place? MEIOSIS
3. When would a gene for one trait be passed with a gene for a different trait?
![Page 34: Introduction to Genetics. Are some traits more common in men or women? Human chromosomes exist in pairs: 23 pairs for a total of 46 chromosomes The.](https://reader031.fdocuments.us/reader031/viewer/2022020103/5a4d1acb7f8b9ab05996f970/html5/thumbnails/34.jpg)
Check Yourself!1. Name Mendel’s three principles of heredity:
PRINCIPLE OF DOMINANCE PRINCIPLE OF SEGREGATION PRINCIPLE OF INDEPENDENT ASSORTMENT
2. What cell process allows the principle of segregation to take place? MEIOSIS
3. When would a gene for one trait be passed with a gene for a different trait?
INDEPENDENT ASSORTMENT