Genetics Chapter 29. Essential Must Know Terminology Chromosome Homologous (homologs) chromosomes...
-
date post
19-Dec-2015 -
Category
Documents
-
view
220 -
download
0
Transcript of Genetics Chapter 29. Essential Must Know Terminology Chromosome Homologous (homologs) chromosomes...
![Page 1: Genetics Chapter 29. Essential Must Know Terminology Chromosome Homologous (homologs) chromosomes – Autosomes – Sex chromosomes – Karyotype Gene Alleles.](https://reader031.fdocuments.net/reader031/viewer/2022032201/56649d2c5503460f94a02b65/html5/thumbnails/1.jpg)
Genetics
Chapter 29
![Page 2: Genetics Chapter 29. Essential Must Know Terminology Chromosome Homologous (homologs) chromosomes – Autosomes – Sex chromosomes – Karyotype Gene Alleles.](https://reader031.fdocuments.net/reader031/viewer/2022032201/56649d2c5503460f94a02b65/html5/thumbnails/2.jpg)
Essential Must Know Terminology
• Chromosome• Homologous (homologs) chromosomes
– Autosomes– Sex chromosomes– Karyotype
• Gene• Alleles
– Dominant (A)– Recessive (a)
• Genotype– Homozygous dominant (AA)– Heterozygous (Aa)– Homozygous recessive (aa)
• Phenotype
![Page 3: Genetics Chapter 29. Essential Must Know Terminology Chromosome Homologous (homologs) chromosomes – Autosomes – Sex chromosomes – Karyotype Gene Alleles.](https://reader031.fdocuments.net/reader031/viewer/2022032201/56649d2c5503460f94a02b65/html5/thumbnails/3.jpg)
Sources of Genetic Variation
• Segregation – 1 set of genes to each gamete
• Independent assortment– 1 allele per trait to a gamete
• Crossing over– Equal gene exchange at
chiasmata• Random fertilization– Only takes 1 of each gamete
![Page 4: Genetics Chapter 29. Essential Must Know Terminology Chromosome Homologous (homologs) chromosomes – Autosomes – Sex chromosomes – Karyotype Gene Alleles.](https://reader031.fdocuments.net/reader031/viewer/2022032201/56649d2c5503460f94a02b65/html5/thumbnails/4.jpg)
Punnett Squares
• Predict probability– Parent alleles on sides– Cross over & down
• Accuracy increased w/ occurrences– Independent events– Multiply w/ multiple events
![Page 5: Genetics Chapter 29. Essential Must Know Terminology Chromosome Homologous (homologs) chromosomes – Autosomes – Sex chromosomes – Karyotype Gene Alleles.](https://reader031.fdocuments.net/reader031/viewer/2022032201/56649d2c5503460f94a02b65/html5/thumbnails/5.jpg)
Dominant – Recessive Inheritance
• Either or situation• Common examples– Dominant: tongue rolling, freckles, and widow’s
peak– Recessive: hitchhiker’s thumb, attached earlobes,
and long palmar muscle• Disorders– Dominant less common, but exceptions exist– Recessive more frequent b/c carriers
![Page 6: Genetics Chapter 29. Essential Must Know Terminology Chromosome Homologous (homologs) chromosomes – Autosomes – Sex chromosomes – Karyotype Gene Alleles.](https://reader031.fdocuments.net/reader031/viewer/2022032201/56649d2c5503460f94a02b65/html5/thumbnails/6.jpg)
Incomplete Inheritance
• Heterozygote w/ own phenotype
• Sickle-cell anemia– SS normal– ss w/ condition– Ss situation specific
• Common w/ African descent
![Page 7: Genetics Chapter 29. Essential Must Know Terminology Chromosome Homologous (homologs) chromosomes – Autosomes – Sex chromosomes – Karyotype Gene Alleles.](https://reader031.fdocuments.net/reader031/viewer/2022032201/56649d2c5503460f94a02b65/html5/thumbnails/7.jpg)
Codominance
• 2+ alleles varies genotypic/phenotypic relationship
• ABO blood type
![Page 8: Genetics Chapter 29. Essential Must Know Terminology Chromosome Homologous (homologs) chromosomes – Autosomes – Sex chromosomes – Karyotype Gene Alleles.](https://reader031.fdocuments.net/reader031/viewer/2022032201/56649d2c5503460f94a02b65/html5/thumbnails/8.jpg)
Sex-linked Inheritance
• Genes on sex chromosomes• X-linked when on X only (most)– Males only need 1– Females need 2; 1 = carrier
• Colorblindness and hemophilia
![Page 9: Genetics Chapter 29. Essential Must Know Terminology Chromosome Homologous (homologs) chromosomes – Autosomes – Sex chromosomes – Karyotype Gene Alleles.](https://reader031.fdocuments.net/reader031/viewer/2022032201/56649d2c5503460f94a02b65/html5/thumbnails/9.jpg)
Polygenic Inheritance
• 2+ genes w/ continuum of phenotypes
• Skin color (3 genes)– AABBCC = darkest– aabbcc = lightest, others = in
between
![Page 10: Genetics Chapter 29. Essential Must Know Terminology Chromosome Homologous (homologs) chromosomes – Autosomes – Sex chromosomes – Karyotype Gene Alleles.](https://reader031.fdocuments.net/reader031/viewer/2022032201/56649d2c5503460f94a02b65/html5/thumbnails/10.jpg)
Environmental Relationships
• Maternal drug use/environment during embryonic development
• Nutrition and diet
• Hormonal alterations
![Page 11: Genetics Chapter 29. Essential Must Know Terminology Chromosome Homologous (homologs) chromosomes – Autosomes – Sex chromosomes – Karyotype Gene Alleles.](https://reader031.fdocuments.net/reader031/viewer/2022032201/56649d2c5503460f94a02b65/html5/thumbnails/11.jpg)
• Pedigrees trace traits through generations
• Fetal testing w/ known risk– Amniocentesis• Most common; after 14th week• Check for genetic markers, enzymes, or
karyotypes
– Chorionic villus sampling• 8th week possible, 10th recommended• Karyotypes
Genetic Screening
![Page 12: Genetics Chapter 29. Essential Must Know Terminology Chromosome Homologous (homologs) chromosomes – Autosomes – Sex chromosomes – Karyotype Gene Alleles.](https://reader031.fdocuments.net/reader031/viewer/2022032201/56649d2c5503460f94a02b65/html5/thumbnails/12.jpg)
Autosomal Disorders
• Dominant– Rare because always expressed embryo/fetal death– Huntington’s disease: impairs motor functioning
• Onset after reproductive age, increase probability of passing
• Recessive– More frequent, because of masking – Albinism: lack of pigmentation– Cystic fibrosis: thick mucus build up in lungs and GI
tract
![Page 13: Genetics Chapter 29. Essential Must Know Terminology Chromosome Homologous (homologs) chromosomes – Autosomes – Sex chromosomes – Karyotype Gene Alleles.](https://reader031.fdocuments.net/reader031/viewer/2022032201/56649d2c5503460f94a02b65/html5/thumbnails/13.jpg)
Abnormal Chromosome Number Disorders
• Normally due to nondisjunction• Turner syndrome: female w/ 45 chromosomes (X0)– Underdeveloped reproductive organs = sterile, short,
broad neck, lack 2° sex characteristics• Klinefelter syndrome: male w/ 47 chromosomes
(XXY)– Underdeveloped reproductive organs = sterile, lack facial
hair, some breast enlargement, long appendages• Down syndrome: 47 chromosomes (trisomy 21)– Slanted eyes, flattened face, short stature, gradient of
mental retardartion