Do Now 2.8 Objectives: 1.Define karyotype, polyploidy, monosomy, trisomy, and nondisjunction...
-
Upload
alicia-allen -
Category
Documents
-
view
212 -
download
0
Transcript of Do Now 2.8 Objectives: 1.Define karyotype, polyploidy, monosomy, trisomy, and nondisjunction...
![Page 1: Do Now 2.8 Objectives: 1.Define karyotype, polyploidy, monosomy, trisomy, and nondisjunction 2.Analyze karyotypes to determine what, if any, chromosomal.](https://reader036.fdocuments.us/reader036/viewer/2022080914/56649ce15503460f949ab378/html5/thumbnails/1.jpg)
Do Now 2.8Objectives:
1. Define karyotype, polyploidy, monosomy, trisomy, and nondisjunction
2. Analyze karyotypes to determine what, if any, chromosomal disorders an individual has.
Task:1. List three processes that produce variation and
diversity in sexually reproducing organisms.
![Page 2: Do Now 2.8 Objectives: 1.Define karyotype, polyploidy, monosomy, trisomy, and nondisjunction 2.Analyze karyotypes to determine what, if any, chromosomal.](https://reader036.fdocuments.us/reader036/viewer/2022080914/56649ce15503460f949ab378/html5/thumbnails/2.jpg)
Karyotypes: Chromosome Pictures
![Page 3: Do Now 2.8 Objectives: 1.Define karyotype, polyploidy, monosomy, trisomy, and nondisjunction 2.Analyze karyotypes to determine what, if any, chromosomal.](https://reader036.fdocuments.us/reader036/viewer/2022080914/56649ce15503460f949ab378/html5/thumbnails/3.jpg)
Polyploidy = more than 2n (i.e. 3n, 4n etc.)• In many organisms,
(especially plants), polyploidy is common and normal. Every banana you eat is triploid, for example.
• In humans and most animals, polyploidy is a dangerous condition associated with tumors and cancer.
• The tetraploid mouse karyotype shown is from a tumor.
![Page 4: Do Now 2.8 Objectives: 1.Define karyotype, polyploidy, monosomy, trisomy, and nondisjunction 2.Analyze karyotypes to determine what, if any, chromosomal.](https://reader036.fdocuments.us/reader036/viewer/2022080914/56649ce15503460f949ab378/html5/thumbnails/4.jpg)
Monosomy and Trisomy
• Monosomy refers to a missing chromosome from the typical diploid set
• Trisomy refers to an extra chromosome
![Page 5: Do Now 2.8 Objectives: 1.Define karyotype, polyploidy, monosomy, trisomy, and nondisjunction 2.Analyze karyotypes to determine what, if any, chromosomal.](https://reader036.fdocuments.us/reader036/viewer/2022080914/56649ce15503460f949ab378/html5/thumbnails/5.jpg)
Nondisjunction: The cause of trisomy and monosomy
• Nondisjunction: a mutation that occurs during meiosis I. Homologous chromosomes do not separate, which produces gametes with extra and missing chromosomes
![Page 6: Do Now 2.8 Objectives: 1.Define karyotype, polyploidy, monosomy, trisomy, and nondisjunction 2.Analyze karyotypes to determine what, if any, chromosomal.](https://reader036.fdocuments.us/reader036/viewer/2022080914/56649ce15503460f949ab378/html5/thumbnails/6.jpg)
Monosomy and Trisomy Disorders in Humans
• Most instances of monosomy and trisomy produce an unviable zygote that spontaneously aborts (miscarries) very early in pregnancy.
• With a few exceptions, the effects of nondisjunction mutations are very serious.
![Page 7: Do Now 2.8 Objectives: 1.Define karyotype, polyploidy, monosomy, trisomy, and nondisjunction 2.Analyze karyotypes to determine what, if any, chromosomal.](https://reader036.fdocuments.us/reader036/viewer/2022080914/56649ce15503460f949ab378/html5/thumbnails/7.jpg)
Sex Chromosome Nondisjunction is the Least Debilitating
• 47 XXX female: “super female.” Most individuals are unaware of the condition. They are at a high risk of producing offspring with sex chromosome trisomy however.
• 47 XYY males: “double Y males.” Many are unaware of the condition. Is associated with increased height, acne, and- perhaps- aggressive behavior
• 45 X females: “Turner Syndrome.” The only viable monosomy in humans
• 47 XXY: “Klienfelter Syndrome.” Male, with female secondary sex characteristics (breasts, less body hair, small testes, etc.)
![Page 8: Do Now 2.8 Objectives: 1.Define karyotype, polyploidy, monosomy, trisomy, and nondisjunction 2.Analyze karyotypes to determine what, if any, chromosomal.](https://reader036.fdocuments.us/reader036/viewer/2022080914/56649ce15503460f949ab378/html5/thumbnails/8.jpg)
Autosomal Trisomy Disorders• Trisomy 21: “Down Syndrome.” Significantly
reduced IQ, characteristic features.• Trisomy 18: “Edwards Syndrome.” Severe disorder
of heart and kidneys. If a fetus survives to birth, the median lifespan is 5-15 days
• Trisomy 13: “Patau Syndrome.” Severe birth defects, including heart and kidney disorders, as well as malformations. 80% of infants do not survive beyond 1 year.
![Page 9: Do Now 2.8 Objectives: 1.Define karyotype, polyploidy, monosomy, trisomy, and nondisjunction 2.Analyze karyotypes to determine what, if any, chromosomal.](https://reader036.fdocuments.us/reader036/viewer/2022080914/56649ce15503460f949ab378/html5/thumbnails/9.jpg)
Recap
• Karyotype: a picture of an organism’s chromosomes, arranged for analysis.
• Polyploidy: a condition of three or more copies of each chromosome. Common in plants, associated with cancer in animals
• Nondisjunction: the failure of a pair of homologous chromosomes to seperate during meiosis, producing gametes where n=22 or n=24
• Monosomy – missing a chromosome (1 of a pair)• Trisomy – extra chromosome (3 of a pair)
![Page 10: Do Now 2.8 Objectives: 1.Define karyotype, polyploidy, monosomy, trisomy, and nondisjunction 2.Analyze karyotypes to determine what, if any, chromosomal.](https://reader036.fdocuments.us/reader036/viewer/2022080914/56649ce15503460f949ab378/html5/thumbnails/10.jpg)
Viable Nondisjunction Disorders
• 47 XXX female: “super female.”• 47 XYY males: “double Y males.”• 45 X females: “Turner Syndrome.”• 47 XXY males: “Klienfelter Syndrome.”• Trisomy 21: “Down Syndrome.”• Trisomy 18: “Edwards Syndrome.”• Trisomy 13: “Patau Syndrome.”