Download Chapters 14 and 15 Anthony Todd http://by123si

Chapters 14 and 15
Anthony Todd
[email protected]
http://by123si.yolasite.com/
Part 1: Warm-Up for Chapter 14
Please define the following terms…
I GET ALL DEFINITIONS FROM THE GLOSSARY AT THE END OF THE BOOK!!!
1. Character:
2. Trait:
3. True-breeding:
4. Allele:
5. Law of segregation:
6. Punnett square:
7. Phenotype:
8. Genotype:
9. Testcross:
10. Law of independent assortment:
11. Incomplete dominance:
12. Codominance:
13. Pleiotropy:
14. Epistasis:
Part II: Applications for Chapter 14
Just a few short-answer questions. You can work alone or with your neighbor…
1. Give the phenotypic and genotypic ratios of a NON-true-breeding widow’s peak
individual with a continuous hairline individual.
Ww x ww
W
w
w Ww ww
w Ww ww
Phenotypic: 2 widow’s peak : 2 continuous hairline
Genotypic: 0 homozygous dominant : 2 heterozygous : 2 homozygous recessive
2. A purple flower (dominant allele) is testcrossed, and half of the offspring are white and
the other half are purple. What is the genotype of the purple flower?
Pp; if PP, all offspring would be purple
3. Show two generations of crossing a true-breeding purple flower with a white flower.
Parent: PP x pp
F1: All Pp
F2: 1 homozygous dominant : 2 heterozygous : 1 homozygous recessive
4. Do a dihyrbid cross of PpWw and PpWw. What are the phenotypic ratios?
PW
Pw
pW
PW
PPWW
PPWw
PpWW
Pw
PPWw
PPww
PpWw
pW
PpWW
PpWw
ppWW
pw
PpWw
Ppww
ppWw
pw
PpWw
Ppww
ppWw
ppww
Both dominant: P_W_ = 9
1 dom./1 rec: P_ww = 3
1 rec./1 dom.: ppW_ = 3
Both recessive: ppww = 1
5. Describe the autosomal recessive disorders. (Must be homozygous recessive)
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Cystic fibrosis – caused by a recessive allele for a chloride channel protein;
characterized by an excessive secretion of mucus and consequent vulnerability
to infection; fatal if untreated; European descent
Albinism – individuals can’t make melanin
Tay-Sachs Disease – caused by a dysfunctional enzyme, leading to accumulation
of certain lipids in the brain; seizures, blindness, and degeneration of motor and
mental performance usually arise a few months after birth; Jewish descent.
Sickle-cell anemia – results in the substitution of a single amino acid in a globin
polypeptide that is part of the hemoglobin protein; characterized by deformed
red blood cells (due to protein aggregation) that can lead to numerous
symptoms (African-descent)
Phenylketonuria – individuals can’t breakdown phenylalanine, so it must be
limited in the diet (accumulation could lead to mental retardation)
6. Describe the autosomal dominant disorders. (Heterpzygotes express disorder)
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Achondroplasia – a form of dwarfism; heterozygotes have the dwarf phenotype
Hypercholesterolemia – causes cholesterol level to be around 500, causing
cardiovascular problems
Huntington’s Disease – characterized by uncontrollable body movements and
degeneration of the nervous system; symptoms usually appear in your 40’s
Polydactyly – causes one to have extra fingers or toes
Part III: Introduction to Chapter 15
Just a few terms to get you thinking about Chapter 15…
1. Chromosome theory of inheritance:
2. Wild type:
3. Sex-linked gene:
4. Linked gene:
5. Genetic recombination:
Part IV: Closing
We are short on time because of this short summer semester. BE SURE to go over these items at
home, in your dorm, at the library – basically anywhere you study:
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Chapter 14
o Know who the father of genetics is (p. 262)
o Understand the basic genetics terms (p. 263-264)
o Understand Mendel’s Law of Segregation and its parts (p. 264-267)
o Understand how to use a Punnett Square and perform a testcross (p. 266-267)
o Understand Mendel’s Law of Independent Assortment (p. 268-269)
o Become acquainted with the multiplication and addition rules to solve genetics
problems (p. 269-270)
o Know the difference between complete dominance, incomplete dominance, and
codominance (p. 271-272)
o Understand pleiotropy, epistasis, and polygenic inheritance (p. 273-274)
o Understand how a pedigree is used (p. 276)
o Understand the autosomal recessive and dominant disorders (p. 277-279)
o Understand the different types of fetal testing (p. 280)
Chapter 15
o VERY IMPORTANT TO UNDERSTAND FIGURE 15.2 (p. 287)
o Understand Morgan’s experiment with the fruit fly (p. 288; Figure 15.4, p. 289)
o Know the chromosomal basis of sex and the inheritance of sex-linked genes (p.
289-290)
o Understand the X inactivation of females (p.291-292)
o Know what linked genes are (p. 292)