Genetics ReviewCompletion1._____ is the passing of traits from one generation to another.•Heredity

2. A plant that receives different genetic information from each parent is•Hybrid/heterozygous

3. A _______ trait covers up other traits.•Dominant

4. In a Punnett square, a small letter (t) stands for a ______ allele.•Recessive

5. A tool used to predict the possible offspring of a mating is called a •Punnett Square

6. The genetic makeup of an organism is called its•Genotype7. ______ is a way an organism looks and behaves as a result of its genotype.•Phenotype8. The study of how traits are inherited through the interactions of alleles•Genetics9. An organism with 2 alleles that are exactly the same is •Homozygous10. An organism that has 2 different alleles for a trait is•Hybrid/heterozygous11. Describe the cause of genetic disorders.•Mutations – a change in a chromosome or gene

12.An organism having two different alleles for a trait is called a. heterozygote  b. homozygous dominant     c. genotype    d. monohybrid cross

  

a

13. The phenotype of an organism a. represents its genetic composition b. reflects all the traits that are actually expressed c. occurs only in dominant pure organisms d. cannot be seen

b

R = round r = wrinkled

14. Give the allele combinations (letters) for the following genotypes:

1. Heterozygous round seeds2. Homozygous dominant seeds3. Wrinkled seeds15. Give the phenotypes for the

followinggenotypes:4. RR5. Rr6. rr

RrRRrr

Homozygous/pure recessive

Homozygous/pure dominant

Heterozygous/hybrid

• A. Is the trait for attached earlobes, dominant or recessive?

• Recessive• B. How do you know?• Only 2 people out

of 14 have attached earlobes.

16. The pedigree shows the inheritance of attached earlobes for 4 generations.

17. Give the phenotypes and genotypes for all possible offspring if a hybrid brown eyed male is crossed with a blue eyed woman.

GenotypeGenotype::

Bb x bbBb x bb b b

B

b

bb

bb

Bb Bb

50% hybrid50% pure recessive

PhenotypePhenotype::50% brown 50% blue

Each has a dominant gene.

Bb - hybrid

18.

19. Use the diagram below to answer the questions that follow.

a. Circle the sex chromosomes.

male

b. What is the sex of this person?

100%

50%

They both have at least 1 dominant gene.

2.

20. Study the pedigree chart below that shows the occurrence of color blindness in three generations of a family.

a. Is there anyone with colorblindness in the first generation?

No

b. Describe the condition of the mother in the first generation.

She is a carrier

c. How many children did the parents in generation 1 have?

2

1 2

3 4 5

6 7

d. Did any of these children get married? If so, which one?

Yes, #4e. Identify which people were colorblind in these 3 generations.

3 & 4

Is this trait dominant or recessive? Why?•Dominant•10 out of 14 people can roll their tongue.

21. The pedigree shows the inheritance of tongue rolling.

22. T = Tall t = shortGive the genotype for each gene combination:

TT:tt: Tt:

Homozygous/pure dominantHomozygous/pure recessiveHeterozygous/Hybrid

23. If an individual possesses two recessive alleles for the same trait, the individual is said to be a. homozygous for the trait            b. haploid for the trait c. heterozygous for the trait          d. mutated

a

  24. Mendel hypothesized that each trait is controlled by a factor, now called a a. gene    b. mate  c. hybrid    d. dominance  

a

25. A heterozygous fire-breathing dragon is crossed with one that does not breathe fire. What kind of offspring might they have? Give phenotype and genotype.

Ff x ff Ff x ff F f

f

f

Ff ff

Ff ffGenotypeGenotype::

50% hybrid50% pure recessive

PhenotypePhenotype::50% fire breathing50% no fire breathing

26. Also in dragons, wings are a dominant trait.  If you crossed two wingless dragons, what kind of offspring

might they have? Give phenotype and genotype.

ww x ww x ww ww w w

w

w

ww ww

ww wwGenotypeGenotype::

100% pure rec

PhenotypePhenotype::100% wingless

27. Which sequence shows the most complex structure to the least complex structure?

1.gene – DNA – chromosome2.DNA – gene – chromosome3.gene – chromosome – DNA4.chromosome – gene – DNA

4

28. Combining DNA from two different organisms is an example of

29. Combining the desirable qualities of 2 different organisms into one is referred to as

30. The process in which genetically identical offspring are produced by using the cells of an organism is called

genetic engineering

selective breeding or hybridization

cloning

31. The type of selective breeding in which organisms with different traits are crossed is called

32. The type of selective breeding in which organisms with similar traits are crossed to preserve the trait is called

Hybridization.

inbreeding.

a. What does structure A represent?

b. What does structure B represent?

c. What technique is illustrated in the diagram?

d. What is this technique used for?

Gene / DNA

Genetic engineering

To produce insulin, growth hormone, clotting factors, genetically modified foods

Recombinant DNA

33.

a. The letter X most likely represents (1.)   bacterial cells that are unable to synthesize insulin (2.)   human cells that are able to synthesize antibodies (3.)   bacterial cells that are able to synthesize insulin (4.)   human cells that are unable to resist antibiotics

b. What is this process an example of?

Genetic engineering

34.

3

35. Genetic engineering has been utilized for the production of

(1)salivary amylase (2)human growth hormone(3)hydrochloric acid (4)uric acid crystals

2

36. Two heterozygous fire breathing dragons are crossed. What kind of offspring might they have? Give phenotype and genotype.

Ff x Ff Ff x Ff F f

F

f

Ff ff

FF FfGenotypeGenotype::

50% hybrid25% pure rec25% pure dom

PhenotypePhenotype::75% fire breathing25% no fire breathing

37. When humans first domesticated dogs, there was relatively little diversity in the species. Today, there are many variations such as the German shepherd and the dalmation. This increase in diversity is most closely associated with

(1) cloning of selected body cells (2) selective breeding (3) mitotic cell division (4) environmental influences on inherited traits

2

a. What technique is represented above?

b. Which sheep is the source of the nucleus in the fused cell?

c. Which animal is a clone?

d. Which sheep provided an egg cell?

e. Which 2 animals are genetically identical? Why?

Cloning

A

The lamb

B

Sheep A and the lamb because the lamb’s chromosomes came from Sheep A’s nucleus.

38.

39. What does this pedigree chart show?

a. How many people are unaffected “carriers”?

b. How many people are affected by the disorder?

c. How many carriers are female?

8

2

5

40. What does this pedigree chart show?

a. How many people are unaffected “carriers”?

b. How many people are affected by the disorder?

c. Is the disorder dominant or recessive?

0

6

recessive

41. One cat carries heterozygous, long-haired traits (Ss), and its mate carries homozygous short-haired traits (ss). Use a Punnett square to determine the phenotype and genotype of this cross.

GenotypeGenotype::

Ss x ssSs x ss S s

s

s

Ss ss

Ss ss

50% hybrid50% pure recessive

PhenotypePhenotype::50% long50% short

42. One flower is heterozygous red and it is crossed with a homozygous dominant plant. Use a Punnett square to determine the phenotype and genotype of this cross.

GenotypeGenotype::

Rr x RRRr x RR R r

R

R

RR Rr

RR Rr

50% hybrid50% pure dominant

PhenotypePhenotype::100% red

43. KARYOTYPES 

•A. Number of sex chromosomes

B. Sex of this person

2

male

44. KARYOTYPES

 

A. Number of sex chromosomes

B. Sex of this person

2

female

45. PEDIGREE CHARTS

 

a. Is this trait dominant or recessive? Explain.

b. How many children did #’s 1 & 2 have?

c. How many generations are represented?

d. How many people have fast twitch muscles?

Recessive because only 4 out of 14 people have the trait.

4

3

10

46. If an egg is fertilized by a sperm with an X chromosome, the offspring will be A. female, XX B. female, XY C. male, YY D. male, XX

47. In a pedigree chart _____. A. a shaded circle represents a normal (unaffected) female B. a square represents an affected male C. a line between a circle and a square represents a union D. all of the above

A

C

48.

49.

4

1

50.

51.

3

2

52.

53.

1

4

100%

R r

R

r

RR Rr

Rr

rr

54.

50

55.

56.

57.

2

3

4

2

58.

59.

3

60.

61.

2

1

62.

2

1

4

Tt x Tt

When these 2 are crossed using a Punnett Square, there is a 25% chance that their offspring will be short (tt)

63.

64.

3

1

65.

3

1

They both have a dominant gene (G) so they are both Green.

66.

Rr rr

Rr rr

67.

68. 69.

4 3

70.

71.

3

3

GG

Gg

GG

Gg

100%

gg x gg

72.