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Unit 10: Genetics Packet
Ms. Leone
Name: ______
Period: ______
Do NOT lose this packet! It contains all of your notes, worksheets, labs, and study sheets to be successful on the exam!
Word / Book Definition / In My Own Words (Please Add Examples / Ms. Leone’s Definition (with example)
Trait
Allele
Homozygous
Heterozygous
Dominant
Recessive
Phenotype
Genotype
Hybrid
Heredity
Genetics
Gene
Segregation
Word / Book Definition / In My Own Words (Please Add Examples / Ms. Leone’s Definition (with example)
Gregor Mendel
P Generation
F1 Generation
F2 Generation

Heredity Exercises – Plants

Dominant Recessive

T = Tall Stem Y = Yellow Seeds t = Short stem y = green seeds

Q = Colored Seed Coat R = Round Seeds q = White Seed Coat r = Wrinkled Seeds

G = Green Pods A = Axial Flowers g = Yellow Pods a = Terminal Flower

  1. Write the correct symbols for the 6 dominant and 6 recessive genes controlling each of the traits above.
    DOMINANT: ______
    RECESSIVE: ______
  1. Write the correct symbols for zygotes that would be homozygous for:
    Tall Stem: _____ Green Seeds: _____

Wrinkled Seeds: _____ Axial Flowers: _____

Round Seeds: ____ Yellow Pods: _____
Yellow Seeds: _____ Short Stem: _____

Terminal Flowers: _____

  1. Write the correct symbols for zygotes that would be heterozygous for:
    Green Pods: _____ Axial Flowers: _____
    Round Seeds: _____ Yellow Seeds: _____
    Tall Stem: _____ Colored Seed Coat: _____
  1. What is the phenotype of the following garden pea monohybrids?
    Gg: _____ Aa: _____ Yy: _____
    Rr: _____ Cc: _____ Tt: _____
  1. What is the genotype of the following garden pea monohybrids?
    Yellow-seeded hybrid: _____ Green pod hybrid: _____
    Tall stem hybrid: _____ Round seed hybrid: _____
    Axial flower hybrid: _____ Color seed coat hybrid: ______

Genetics Vocabulary and Probability

1.  In pea plants, round seeds are dominant over wrinkled seeds.

·  First assign a letter to use for your traits. Then…

·  Write the genotype for a heterozygous, round parent: _____

·  Write the genotype for a wrinkled parent: _____

·  What is the probability that the round parent will contribute a wrinkled allele: _____

·  What is the probability that the wrinkled parent will contribute a wrinkled allele: _____

·  What is the probability that crossing these plants would produce a wrinkled offspring: _____

2.  In humans, brown eyes are dominant over blue eyes.

·  First, assign a letter for the traits. Then…

·  Write the genotype for a homozygous dominant parent: _____

·  Write the genotype for a heterozygous dominant parent: _____

·  What is the probability that the homozygous parent will contribute a blue allele: _____

·  What is the probability that the heterozygous parent will contribute a blue allele: _____

·  What is the probability that a cross of these parents would produce a child with blue eyes: _____

Complete Dominance Test Crosses – Homework Problems

Do the following problems on a separate sheet of paper! Make sure if you need to, you are using the “four step” method I taught you in class!

1.  Define complete dominance.

2.  Plant height represents complete dominance. A tall pea plant is crossed with a short pea plant. All 55 of the offspring are tall. What is the genotype of the tall parent?

3.  In squash, white fruit color is completely dominant to yellow fruit color. If a cross between a white-fruited plant and a yellow-fruited plant yielded 43 white and 37 yellow offspring, what is the white parent’s genotype?

4.  In hair, blond hair is recessive to brown hair. A blonde-haired man marries a brown-haired woman. They have four children, all of whom have brown hair. What is the genotype of their mother? If the mother is heterozygous, what is the probability that the couple will have a blonde child?

5.  You find a seed of a pea plant. You plant it and a purple-flowered plant grows. How could you find out if the genotype of this plant, knowing that purple (P) is dominant and white (p) is recessive?

6.  In jelly fish, long tentacles are dominant to short tentacles. Two jelly fish have 4 baby jellies. One has short tentacles and the other three have long tentacles. What are the ONLY possible genotypes of the parents? HINT: You need to not only work backwards but write down everything you know before you can start the problem!

Should This Dog Be Called Spot

Imagine this microscopic drama. A sperm cell from a male dog fuses with an egg cell from a female dog. Each dog’s gamete carries 39 chromosomes. The zygote that results from the fusion of the gametes contains 78 chromosomes – one set of 39 chromosomes from each parent. One pair of the zygotes chromosomes are shown below.

Each chromosome of the homologous pair contains alleles for the same traits. But one chromosome may have a dominant allele and the other a recessive allele. Use the picture to answer the questions.

TRAIT / DOMINANT GENES / RECESSIVE GENES
Hair Length / Short (L) / Long (l)
Hair Texture / Wiry (T) / Silky (t)
Hair Curliness / Curly (H) / Straight (h)
Coat Pattern / Spotted (A) / Solid (a)

1.  Will the new puppy have spotted hair? Explain.

2.  Does the female dog have a spotted coat? Explain how you know.

3.  Does the male dog have a spotted coat? Explain how you know.

4.  What will the texture of the puppy’s coat be?

5.  Will the texture of the puppy’s coat resemble that of either of its parents? Explain.

6.  Will the puppy have straight or curly hair?

7.  Does the female dog have curly hair? Explain how you know.

8.  Does the male dog have curly hair? Explain how you know.

9.  Define the term HETEROZYGOUS.

10.  For which traits is the puppy heterozygous?

11.  Define the term HOMOZYGOUS.

12.  For which traits is the puppy homozygous?

13.  Explain why you cannot completely describe the parent’s traits but you can describe the puppy’s traits completely.

Determining Genotype from Phenotype Lab

An organism can be thought of as a large collection of phenotypes. A phenotype is the appearance of a trait and is determined by pairs of genes. The pairs of genes represent the genotype for the trait. If you were told a large enough number of phenotypic traits that belonged to another person, you would be able to recognize that person.

In this exploration, you will determine some of your own phenotypic traits. From these, you will be able to determine what your genotypes are for some of the traits. If a trait is dominant and you possess that trait, you will not be able to tell determine your exact genotype because you could be either homozygous dominant or heterozygous for the gene. However, if a trait is determined by incomplete dominance, you can tell it you are homozygous or heterozygous. Genotypes of recessive traits can be identified. By comparing your genotypes and phenotypes with other people in your class, you will see why you are a unique individual. Given the almost limitless number of gene combinations, it is almost impossible that anyone would have all the same traits as you.

Objectives

·  Determine your phenotype for nine different characteristics

·  Determine your possible genotypes for the nine different characteristics

·  Compare your phenotypes and genotypes with those of other students in the class

·  Evaluate your uniqueness as an individual

Materials

·  PTC Taste Paper

·  Untreated Taste Paper

Procedure

  1. Obtain one piece each of the PTC paper and untreated paper from your teacher. First, place the untreated paper on your wet tongue to see how it tastes. Then dispose of it in the garbage, and place the PTC paper on your wet tongue to see if you can taste phenylthiocarbamide – PTC.
  2. PTC is quite bitter and you will notice immediately if you have the ability to taste this chemical. If you can taste PTC, enter “taster” in the proper place in the “Your Phenotype” column in the table. If you cannot taste the chemical, enter “no- taster” in the table. Discard the taste paper in the garbage.
  3. Now that you have determined your phenotype, enter in the column marked “Your Possible Genotypes” what your genotype could be. Tasters are either TT or Tt. Non-tasters are tt.
  4. For each of the following traits, observe and record your phenotype in the table. Then record your possible genotypes.

Part A – Hairline

The widow’s peak hairline comes to a point in the center of the forehead (WW or Ww). Individuals without a widow’s peak are ww.

Part B – Eye Shape

Almond-shaped eyes (AA or Aa) are dominant to round eyes (aa).

Part C – Eyelash Length

Long Eyelashes (EE or Ee) are dominant to short eyelashes (ee).

Part D – Tongue Rolling

The ability to roll the tongue (CC or Cc) is dominant to not having this ability (cc).

Part E – Thumbs

One whose thumb tip bends backwards more than 30 degrees is called a hitch-hiker’s thumb. It is a dominant trait (BB or Bb) to having a straight thumb (bb).

Part F – Lip Thickness

Thick lips (LL or Ll) are dominant to thin lips (ll).

Part G – Hair Texture

Curly hair (HH) is incompletely dominant to straight hair (SS). Those that have wavy hair are HS.

Part H – Inter-Eye Distance

The distance between the eyes is an example of incomplete dominance. Close set eyes are DD, eyes set far apart are FF and medium set eyes are DF.

Part I – Lip Protrusion

Protruding lips (PP) are incompletely dominant to no protruding lips (NN). Slightly protruding lips are PN.

Human Phenotypes and Genotypes
Traits / Your Phenotype / Your Possible Genotypes
Dominant / Recessive
PTC Taste / Taster / Non-Taster
Hair Line / Widows Peak / Straight Line
Eye Shape / Almond / Round
Eyelash Length / Long / Short
Tongue Dexterity / Can Roll / Can’t Roll
Thumb / Hitchhiker’s Thumb / Straight Thumb
Lip Thickness / Thick / Thin
Hair Texture / Curly / Wavy / Straight
Inner-Eye Distance / Close Together / Medium Distance / Far Apart
Lip Protrusion / Protruding / Slightly Protruding / Not Protruding

Analysis

  1. Which traits do you have that are dominant?
  1. Which traits do you have that are recessive?
  1. Which of your traits are governed by incomplete dominance
  1. Which of your traits do you share with one or more classmates?
  1. Which traits are unique to you?
  1. If you and a particular classmate shared all of the same traits examined in this exploration, what traits could you describe to prove your uniqueness?
  1. What determines your traits?
  1. With knowledge of the phenotype of a human, how can a person’s genotype be determined?
  1. Why was untreated paper used in the PTC taste test?

Bikini Bottom Genetics

1.  For each genotype below, indicate whether it is heterozygous (HE) or homozygous (HO).

TT ______Pp ______dd ______

Ff ______Tt ______FF ______

2.  Which of the genotypes listed above in question one would be considered purebred?

3.  In Squidward’s family, blue body color (B) is dominant to green (b). Determine the phenotype for each of the genotypes listed below based on this information.

BB ______Bb ______bb______

4.  If tall eyeballs (T) are dominant to short eyeballs (t), give the genotypes that are possible for members of Mr. Krabb’s family.

Tall eyeballs ______Short eyeballs ______

5.  SpongeBob is known for his big round eyes (R), which is dominant over an oval shape (r). If he is heterozygous for his round eye shape and marries a woman with oval eyes, what type of eyes might their kids have?

  1. List the genotypes for each
  2. Heterozygous Eyes ______
  1. Oval Eyes ______
  1. Complete the Punnett square to show the possibilities that would result if SpongeBob had children with an oval eyed woman.
  1. List the possible genotypes and phenotypes for their children
  1. What are the chances of having a child with round shaped eyes? ______%
  1. What are the chances of having a child with oval shaped eyes? ______%

6.  Determine the genotypes for each of the following using the information from the chart in #1.

  1. Heterozygous for round eyes ______
  1. Homozygous for long nose ______
  1. Purebred square pants ______
  1. Hybrid yellow body ______

7.  One of SpongeBob’s cousins, SpongeBillyBob, recently met a cute a cute girl named SpongeSusie at a local dance and they fell in love. Use your knowledge of genetics to answer the questions below.

  1. If SpongeSusie’s father is a heterozygous square pants and her mother is a round pants, what is her genotype? Complete the Punnett square below to show the possible genotypes that would result to help you determine SpongeSusie’s genotype
  1. What is SpongeSusie’s genotype?
  1. SpongeBillyBob is heterozygous for his square pants. What is his genotype? ______
  2. Complete the Punnett square below to show the possibilities that would result if SpongeBillyBob and SpongeSusie had children.
  1. List the possible genotypes and phenotypes for the kids.
  1. What is the probability of kids with square pants? ______%

8.  SpongeBob’s aunt and uncle, SpongeWilma and SpongeWilbur, have the biggest round eyes in the family. SpongeWilma is believed to be heterozygous for her round eye shape, while SpongeWilbur’s family brags that they are a pure line. Complete the Punnett square to show the possibilities that would result if SpongeWilma and SpongeWilbur had children.

  1. Give the phenotype for SpongeWilma: ______and SpongeWilbur: ______
  2. Complete the Punnett square to show the possibilities that would result if they had children.
  1. List the possible genotypes and phenotypes for the kids.
  1. What is the probability that the kids would have round eyes? ____ %
  2. What is the probability that the kids would be oval eyes? ____ %

9.  SpongeBillyBob’s mother is so proud of her son and his new wife, SpongeSusie, as they are expecting a little sponge. She knows that they have a 50% chance of having a little roundpants, but is also hoping the new arrival will be blue (a recessive trait) like SpongeSusie and many members of her family. If SpongeBob is heterozygous for his yellow body color, what are the chances that the baby sponge will be blue? Create a Punnett square to help you answer this question.