Unit 5 Meiosis and Genetics
Chapter 13 – Homework
Meiosis and Sexual Life Cycles
Level 1 Items
AP Biology students will be able to:
1. Recognize the general relationships between Genes, DNA, and Chromosomes.
2. Identify characteristics, advantages, and limitations of asexual and sexual reproduction.
3. Recognize several sexual life cycles differing in the timing of meiosis and fertilization.
4. Recognize the stages and characteristics of the meiosis cell division process.
5. Contrast and compare meiosis to mitosis.
6. Identify sexual sources of genetic variation.
Outline
A. Genes, DNA, and Chromosomes: Overview
1. Definitions
a. Heredity
b. Genetics
c. Genes
d. Locus
2. Linkages between these terms
3. Relationships to Sexual Reproduction
B. Sexual vs Asexual Reproduction
1. Asexual Reproduction
a. Definition
b. Examples
c. Advantages/Limitations
2. Sexual Reproduction
a. Definition
b. Examples
c. Advantages/Limitations
C. The Variety of Sexual Life Cycles
1. Human Life Cycle
a. Chromosome Number
1. Diploid
2. Haploid
3. Polyploids
b. Gametes
1. Sperm
2. Egg
c. Fertilization
d. Zygote
2. Life Cycle Comparisons
a. Animals
b. Some Fungi and Algae
c. Plants - Alternation of Generations
1. Sporophyte Phase
2. Gametophyte Phase D. Meiosis
1. Meiosis I
AP Biology students will understand:
a. Prophase I
1. General Characteristics
2. Synapsis - Tetrad formation
3. Chiasma
b. Metaphase I
1. Characteristics
2. Chromosome Alignment
c. Anaphase I
1. Tetrad Separation
2. Fate of Duplicate Chromosomes
d. Telophase I
1. Characteristics
2. Cytokinesis
2. Interkinesis
a. Characteristics
b. Duration
3. Meiosis II
a. Prophase II
b. Metaphase II
c. Anaphase II
d. Telophase II
e. Cytokinesis
4. Results of Meiosis
E. Comparison of Meiosis and Mitosis
1. DNA Replication
2. Number of Divisions
3. Synapsis
4. Number of Daughter Cells
5. Ploidy Levels
6. Importances and Uses
F. Sexual Sources of Genetic Variation
1. Independent Assortment of Chromosomes
a. Definition/mechanism
b. Importances
c. Human Example
2. Crossing Over
a. Definition/mechanism
b. Importance
3. Random Fertilization
a. Definition/mechanism
b. Importance
Unit 5 Meiosis and Genetics
Chapter 13 – Homework
Meiosis and Sexual Life Cycles
1. Describe the advantages and disadvantages of asexual and sexual reproduction.
2. Discuss which type of reproduction is “best” for continuing a species through time.
Be sure to defend and explain your logic.
3. Contrast and compare meiosis to mitosis. Be sure to include several factors of
similar/differences in your discussion. (This question could be set up in a table format.)
4. A horse breeder claims that the future offspring from a prize stallion and mare will be identical
to the award winning offspring they’ve already produced. In fact, he’s willing to sell you an
investment opportunity on their next offspring. Assuming you had the money, discuss why
you would or would not invest it this way.
5. The Genetic Genie in the DNA bottle has granted you just one wish for hybridizing “widgets”.
You can create variation in your widgets by random assortment of chromosomes, random
fertilization, or crossing-over. Which method do you choose? Explain.
6. Discuss how does the karyotype of a human female differs from that of a human male.
7. Describe how the chromosomes in a cell at metaphase of mitosis are similar to and/or
different from the chromosomes in a cell at metaphase of meiosis II.
8. The diploid number for fruit flies is 8 while that for grasshoppers is 46. If no crossing over took
place, would the genetic variation among offspring from a given pair of parents be greater in
fruit flies or grasshoppers? Explain.
9. Describe under what circumstances crossing over during meiosis would NOT contribute to
the genetic variation among daughter cells.
Unit 5 Meiosis and Genetics
Chapter 14-Outline/Homework
Mendel and the Gene Idea
Level 1 Items
AP Students should be able to:
1. Recognize Mendel's experiments and their role in the scientific discovery of genetic principles.
2. Identify Mendel's Laws of Genetics.
3. Recognize the use and application of probability in genetics.
4. Recognize the basic Mendelian crosses and genetic terminology.
5. Recognize various extensions of Mendelian genetics and their effect on inheritance patterns.
6. Identify human traits that exhibit Mendelian inheritance patterns.
7. Recognize methods used in genetic screening and counseling.
Outline
A. Mendel's Model as a Case Study in Scientific Process
1. Mendel's Experimental Approach
a. Historical Overview of Genetics
b. Mendel's Pea Experiments
1. Peas and their Traits
2. Pea Flowers Structure
3. Example Cross
4. Results and Importance
2. Mendel's Law of Segregation
a. Mendel's Hypothesis
1. Alleles
2. Equal Parental Contributions
3. Dominant and Recessive
4. Gamete Production
b. Law of Segregation Defined
c. Useful Terminology
1. Heterozygous and Homozygous
2. Phenotype and Genotype
d. The Basic Mendelian Crosses Summarized
1. Six Basic Crosses
2. Expected Ratios
e. Test Cross
1. Definition
2. Applications
3. Inheritance and Probability
a. Definition of Probability
b. Multiplication Rule
c. Application to Genetics
4. Mendel's Law of Independent Assortment
a. Dihybrid Cross Example
b. Definition of the Law
c. Application in Genetics
B. Extending Mendelian Genetics
1. Incomplete Dominance
a. Definition
b. Example
Answer the following questions on a separate sheet of
paper.
1. Pattipan squash are either white or yellow. In
growing pattipans, you notice that in order to
produce white squash, at least one parent
must be white. Which color is dominant?
Explain.
2. In rabbits, the homozygous CC is normal, Cc
results in rabbits with deformed legs, and cc is
lethal. For coat color, BB produces black, Bb
brown, and bb a white coat. Give the
phenotypic proportions of offspring from a
cross of a deformed-leg, brown rabbit with a
deformed-leg, white rabbit.
3. Polydactyly (extra fingers and toes) is due to a
dominant gene. A father is polydactyl, the
mother has the normal phenotype and they
have had one normal child. What is the
genotype of the father? Of the
mother? What is the probability that a second
child will have the normal number of digits?
4. The ability to taste phenylthiocarbamide (PTC)
is controlled in humans by a single dominant
allele (T). A woman nontaster married a man
taster and they had three children, two boy
tasters and a girl
nontaster. All the grandparents were tasters.
Create a pedigree chart for this family for this
trait. (Solid symbols should signify nontasters
(tt).) Where possible, indicate whether tasters
are TT or Tt.
5. John and Sue each has a sibling with cystic
fibrosis (CF), but neither John nor Sue nor their
parents have the disease.
a) Calculate the probability that John or Sue
have the trait for CF.
b) Calculate the probability that John or Sue
will have a child with CF.
c) If genetic testing shows that John is not a
carrier for CF, what is the probability that they
will have a child with CF?
Unit 5 Meiosis and Genetics
c. Effect on Mendelian Ratios
2. Codominance
a. Definition
b. MN Blood Group Example
c. Effect on Mendelian Ratios
3. Multiple Alleles
a. Definition
b. ABO Blood Group Example
c. Effect on Mendelian Ratios
4. Pleiotropy
a. Definition
b. Example
5. Epistasis
a. Definition
b. Examples
c. Effect on Mendelian Ratios
6. Polygenic Inheritance
a. Definition
b. Methods of Detection
c. Examples
d. Effect on Mendelian Ratios
C. Mendelian Inheritance in Humans
1. Human Pedigree Charts
a. Why Used
b. Basic Symbols
c. Dominant Inheritance Pattern
d. Recessive Inheritance Pattern
2. Recessive Traits - Human Examples
a. Albinism
b. Cystic Fibrosis
c. Tay-Sachs
d. PKU
e. Sickle-Cell Anemia
3. Dominant Traits - Human Examples
a. Huntington's Disease
b. Other Examples
4. Multifactorial Disorders
a. Genetic Influence
b. Environmental Influence
5. Genetic Screening and Counseling
a. Fetal Testing
1. Amniocentesis
2. Chorionic Villi Sampling
b. Newborn Screening
c. Counseling Calculations
1. General Formula
2. Example Calculations
Unit 5 Meiosis and Genetics
Chapter 15 –Outline
The Chromosomal Basis of Inheritance
Level I Items
AP Students should be able to:
1. Recognize the relationships between Mendelian Inheritance patterns and chromosomes.
2. Identify linked genes and their effect on inheritance patterns.
3. Recognize the chromosomal basis of recombination in unlinked and linked genes.
4. Recognize how crossover data is used to construct a genetic map.
5. Identify the chromosomal basis of sex in humans.
6. Recognize examples of sex-linked disorders in humans.
7. Identify X-inactivation and its effect in females.
8. Recognize sources and examples of chromosomal alterations in humans.
9. Identify examples of abnormalities in sex chromosome number in humans.
10. Recognize the basis and effects of parental imprinting of genes in human inheritance patterns.
11. Recognize the basis and effect of extranuclear inheritance on genetic inheritance patterns.
Outline
A. The Chromosomal Theory of Inheritance
1. Historical Overview
2. Theory Definition
3. Linked Genes
a. Definition
b. Examples
c. Effect on Inheritance
d. Effect of Crossing Over
B. The Chromosomal Basis of Recombination
1. The Recombination of Unlinked Genes
a. Dihybrid Cross Example
b. Genetic Results
2. The Recombination of Linked Genes
a. Crossing Over Review
b. Genetic Results
C. Genetic Maps
1. Map Construction Theory
2. Example of Map Construction
3. Fruit Fly Map Example
D. Sex Chromosomes and Sex-Linked Inheritance
1. The Chromosomal Basis of Sex in Humans
a. X Chromosome
b. Y Chromosome
c. XX and XY Genotypes and Phenotypes
2. Sex-Linked Disorders in Humans
a. Basis for Sex-Linkage
b. Inheritance Patterns
c. Examples
1. Color Blindness, Duchenne's
Muscular Dystrophy, Hemophilia
AP students will understand;
3. X-Inactivation in Females
a. Lyon Hypothesis
b. Barr Bodies
c. Females as Mosaics
E. Chromosomal Alterations
1. Chromosome Number
a. Aneuploidy
1. Monosomy
2. Trisomy
b. Polyploidy
c. Causes of Number Change
2. Chromosome Structure
a. Deletions
b. Duplications
c. Translocations
d. Inversions
3. Human Examples
a. Trisomy 21
b. Turner Syndrome
c. Kleinfelter Syndrome
d. Metafemale
e. Supermale
f. Philadelphia Chromosome
F. Parental Imprinting of Genes
1. Definition
2. Prader-Willi/Angelman Enigma
3. Fragile-X syndrome
G. Extranuclear Inheritance
1. Definition
2. Effects on Inheritance Patterns
3. Mitochondria Example
4. Chloroplast Example
Unit 5 Meiosis and Genetics
Chapter 15 – Homework
The Chromosomal Basis of Inheritance
1. Recombination frequency is given below for several gene pairs. Create a linkage map (the order
of the genes on the chromosome) for these genes, showing the map unit distance between loci.
j-k 12%, j-m 9%, k-l 6%, l-m 15%
2. Mendel’s law of independent assortment applies to genes that are on different homologous
chromosomes. However, two of the traits Mendel studied were actually located on the same
chromosome.
a) Explain why genes located more than 50 map units apart behave as if they are not linked.
b) Discuss how one can determine whether these genes are linked and what the relative distance
is between them?
3. In guinea pigs, black (B) is dominant to brown (b), and solid color (S) is dominant to spotted (s).
A heterozygous black, solid-colored pig is mated with a brown, spotted pig. The total offspring for
several litters are: 16 black solid, 5 black spotted, 5 brown solid and 14 brown spotted.
a) Determine if the genes are linked.
b) If the genes are linked, calculate how many map units are they apart.
4. A woman is a carrier for a sex-linked lethal gene that causes an embryo with the gene to
spontaneously abort. She has nine living children, but has lost several embryos to spontaneously
abortions. How many of the living children do you expect to be boys?
5. A dominant sex-linked gene (B) produces white bars on black chickens, as seen in the Barred
Plymouth Rock breed. A clutch of chicks has equal numbers of black solid and barred chicks.
(Remember that sex is determined by the Z-W system in birds: ZZ are males and ZW are females)
a) If only the females are found to be black solid, what were the genotypes of the parents?
b) If males and females are evenly represented in the black solid and barred chicks, what were the
genotypes of the parents?
6. Mrs. Talley once had a female student that was color-blind. Explain what he was able to state say
immediately about her father.
7. Women who are carriers for color-blindness usually have patches of color-blind and normal
color vision areas on the retinas (the area at the back of the eye that receives light). Explain why
this would be so.
8. Explain the relationship between Mendel’s Law of Segregation and the Independent Assortment
of Chromosomes.
9. Neither Steve or Ruth are have colorblindness, but their firstborn son does have it.
a) Calculate the probability that a second child of this couple will have the condition.
b) Calculate is the probability of colorblindness if the second child is a boy.
c) Calculate the probability of colorblindness if the second child is a girl.
Unit 5 Meiosis and Genetics