Cell Cycle

DATE___________________

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings

ABCD

 

2. Describe the differences between the somatic cell s and gametes in your body.

	Somatic cell	Gamete
Number of chromosomes
Ploidy (haploid or diploid)
Example

3. Phases of Meiosis– An organism’s body cells have 4 chromosomes (2 pairs)

A. Identify the major characteristics of each phase that differs from Mitosis.

B. OPTIONAL –Draw a picture to illustrate these characteristics.

Meiosis Phase	A. Characteristics of phase that differs from Mitosis	B. OPTIONAL-Illustration of phase
Interphase
Prophase I
Metaphase I
Anaphase I
Telophase I & cytokinesis
Prophase II
Metaphase II
Anaphase II
Telophase II & cytokinesis

#4 OPTIONAL PRACTICE

4. Phases of Meiosis– An organism’s body cells have 2 chromosomes (1 pair)

A. Identify the major characteristics of each phase that differs from Mitosis.

B. Draw a picture to illustrate these characteristics.

Meiosis Phase	A. Characteristics of phase that differs from Mitosis	B. Illustration of phase
Interphase
Prophase I
Metaphase I
Anaphase I
Telophase I & cytokinesis
Prophase II
Metaphase II
Anaphase II
Telophase II & cytokinesis

5. Fruit flies have a diploid number of 8, and honeybees have a diploid number of 32. Assuming no crossing over, is the genetic variation among offspring from the same two parents likely to be greater in fruit flies or honeybees? Explain.

Chapter 14-Mendel and the Gene Idea

1. Genetics Terminology

Match each commonly used genetics term with its appropriate definition or example.

TERMS: DEFINITIONS AND EXAMPLES:

​__ heterozygous a. Blue-eyed blonde mates with brown-eyed brunette

__ homozygous b. BB or bb

__ monohybrid cross c. not on sex chromosomes

__ autosomal d. blue or brown eyes

__ genotype e. Bb

___ phenotype f. locus on a chromosome that codes for a given polypeptide

__ gene g. Blonde mates with brunette.

__ allele h. BB, Bb, or bb

__ dihybrid cross i. Males have only one for each gene on the X chromosome

2. Make a punnett square using the following information.

Traits: Oval eyes = A, Round eyes = a

Parents: Mom Aa, Dad aa

-What eye shape does Mom have?

-What eye shape does Dad have?

-What fraction of the offspring will have oval eyes?

-What fraction of the offspring will have round eyes?

-What fraction of the offspring will have the Homozygous Dominant genotype AA?

-What fraction of the offspring will have the Heterozygous genotype Aa?

-What fraction of the offspring will have the Homozygous Recessive genotype aa?

3. Make a punnett square using the following information.

Traits: Brown eyes = B, Blue eyes = b

Parents: Mom Bb, Dad Bb

-What eye color does Mom have?

-What eye color does Dad have?

-What fraction of the offspring will have brown eyes?

-What fraction of the offspring will have blue eyes?

-What fraction of the offspring will have the Homozygous Dominant genotype BB?

-What fraction of the offspring will have the Heterozygous genotype Bb?

-What fraction of the offspring will have the Homozygous Recessive genotype bb?

4. Multi-hybrid cross #1:

3 characters = trihybrid cross

Parent 1: Purple flowers (Pp), Yellow (Yy), Round (Rr)

Parent 2: Purple flowers (Pp), green (yy), wrinkled (rr)

Parents: PpYyRr X Ppyyrr

Question: What percentage of the offspring from this cross would be predicted to have the following genotypes: Ppyyrr, PPyyrr

1. Consider each character separately (make a punnett square for each character)

Parents: PpYyRr X Ppyyrr:

Pp X Pp =

Yy X yy =

Rr X rr =

2. Calculate probability for each genotype using the Rule of Multiplication

Ppyyrr ½ x ½ x ½ = 2/16

PPyyrr

3. Use the Rule of Addition to determine the probability of offspring that have the following genotypes:

Ppyyrr =2/16

PPyyrr =

5. Multi-hybrid Cross #2

3 characters = trihybrid cross

Parent 1: White flowers (pp), Yellow (Yy), Wrinkled (rr)

Parent 2: Purple flowers (Pp), Green (yy), Round (Rr)

Parents : ppYyrr X PpyyRr

Question: What percentage of the offspring from this cross would be predicted to have the following genotypes: ppyyrr (phenotype: white flowers and green and wrinkled seeds)?

1. Consider each character separately (make a punnett square for each character)

Parents: ppYyrr X PpyyRr:

pp X Pp =

Yy X yy =

rr X Rr =

2. Calculate probability for the genotype using the Rule of Multiplication

ppyyrr=

3. Use the Rule of Addition to determine the probability of offspring that have the genotype ppyyrr (phenotype: white flowers and green and wrinkled seeds)?

6. Pedigree for a recessive trait . Determine the genotype and phenotype of each individual in the pedigree shown below. Use A for dominant, a for recessive.

7. Joan was born with six toes on each foot, a dominant trait called polydactyly. Two of her five siblings and her mother, but not her father, also have extra digits. Draw a pedigree inclucing all family members mentioned in the question. Use D and d to symboloze the alleles for this character. What is Joan’s genotype for the “number-of-digits” character?

Chapter 15-The Chromosomal Basis of Inheritance

1. A heterozygous brown-eyed human female who is a carrier of color blindness marries a blue-eyed male who is not color-blind. Color blindness is a sex-linked trait. Assume that eye color is an autosomal trait and that brown is dominant over blue. What is the probability that any of the offspring produced have the traits listed? Construct two punnett squares, one for hair color and one for color blindness.

Eye color (autosomal trait):

	B	b
b
b

Color blindness (sex-linked trait):

	XA	Xa
XA
Y

a. Brown eyes

b. Blue eyes

c. Color blind OFFSPRING?

d. What fraction of the MALE OFFSPRING will be color-blind?

e. What fraction of the FEMALE OFFSPRING will be color-blind?

f. What fraction of the FEMALE OFFSPRING will be carriers for colorblindness?

g. What fraction of the MALE OFFSPRING will be carriers for colorblindness?

h. What fraction of the TOTAL OFFSPRING will have Brown-eyes and be color-blind?

i. Why do males show sex-linked traits more often than females?

2A. Describe the process of X inactivation in female mammal body cells.

2B. Why does this process not occur in male mammal body cells?

2C. Discuss at least one possible reason for this phenomenon.

3. Construct a linkage map using the following gene recombination frequencies.

The Recombination Frequency between characters:

A and B = 30%, A and C = 20%, and B and C = 10%.

4. Rip two long strips of paper from a piece of scrap paper. On the end of each strip of paper write “A B C D”. These letters represent gene alleles on non-sister chromosomes that are crossing over during prophase I of meiosis. Rip one strip between the B and C and Rip the other strip between the C and D. Transfer the pieces you ripped off to the other non-sister. Record the sequence of alleles on each non-sister below.

Sequence on non-sister 1:

Sequence on non-sister 2:

-What type of chromosome alterations have occurred?