Mendelian Genetics ReviewName:

Period:Date:

MENDEL’S WORK

  1. Who was Gregor Mendel?
  1. In Mendel’s first experiment, he began by cross pollinating two purebred pea plants with opposite traits. How is cross-pollination different from self-pollination?

How many different phenotypes were present in the offspring (F1)?

When the F1were self pollinated, what was the phenotype ratio in the F2?

Mendel did a similar experiment looking at two traits at a time (a dihybrid cross). Again, hisF1offspring were all heterozygous for both traits. What phenotype ratio did he get in his F2 generation?

______: ______: ______: ______

  1. Mendel’s work resulted in three important genetic principles. Name them according to their descriptions below:

According to the Law of ______

If the two alleles differ and only one allele controls the organism's appearance while the other has no noticeable effect on the organism's appearance.

According to the Law of ______

In the formation of gametes, one allele from each parent is passed down to the offspring.

According to the Law of______

The inheritance of one trait does not affect the inheritance of each other resulting in a random mix of traits. For example, in pea plants a green pod can have round or wrinkled seeds, and the same is true of a yellow pod.

VOCABULARY

  1. Match the word from the word bank below with its definition:

genetics heredity trait pure-breeding dominant recessive allele fertilization

______A characteristic that can be observed such as hair color, seed shape, flower color, etc

______The joining of a sperm and egg to make a zygote

______A gene choice that MASKS ANOTHER choice for a trait

______A gene choice that IS MASKED BY ANOTHER choice for a trait

______The branch of biology that studies how characteristics are transmittedfrom parent to offspring

______The passing of characteristics from parent to offspring

______An alternative choice for a gene (such as brown, green, or blue eyes)

______A homozygous organism that always produces offspring identical to itself if self pollinated

  1. Define the following terms and give a synonym and/or example of each.

Heterozygous- ______

synonym: ______

example: ______

Homozygous- ______

synonyms: ______OR ______

example: ______

Genotype - ______

example: ______

Phenotype - ______

example: ______

Your Grandparents
F2 Generation
  1. Complete the following table:
  1. Indicate the resulting gametes from the genotypes (Hint: FOIL)

AABb: ______AABB: ______

AaBB:______AaBb:______

ONE TRAIT (MONOHYBRID) CROSSES

  1. The ability to curl your tongue up on the sides is dominant to not being able to roll your tongue.

a) Make a key. R = ______r =______

b) Write all the possible genotypes below. Below them write the corresponding phenotype.

Genotype: / Genotype: / Genotype:
Phenotype: / Phenotype: / Phenotype:

c) Cross a homozygous dominant woman with a homozygous recessive man.

Parent Genotypes: ______X ______

Circle the mother’s gametes on the Punnett square.

How many of them have the

same phenotype as their mom? ______

d) Cross two heterozygotes.

Parent Genotypes: ______X ______

How many of the kids will

havethe same genotype as their father? ______

e) A woman who can roll her tongue marries a man who cannot. Their first child has his father's phenotype. What are the genotypes of the mother, father, and child?

Mother’s genotype: ______

Father’s genotype: ______

Children’s genotype:______

f) In a cross between two parents who can both roll their tongue,

3 children who can roll their tongues and one who cannot are produced.

What was the genotype of the parents? Show how you know using the Punnett square.

Parent Genotypes: ______X ______

TWO TRAIT (DIHYBRID) CROSSES

  1. About 70% of Americans perceive a bitter taste from the chemical phenylthiocarbamide (PTC). The ability to taste this chemical results from a dominant allele (J) and not being able to taste PTC is the result of having two recessive alleles (j). Albinism with normal pigment being dominant (A) and the lack of pigment being recessive (a).

J = j = A = a =

a) Write the genotype for a female who is heterozygous for taste and albino. Write the genotype for a male who is homozygous recessive for both traits.

Female genotype: ______

Male genotype: ______

b) Write the gametes that are produced from the female and male.

Female gametes: ______

Male gametes: ______

c) Perform a cross between the two individuals.

What is the phenotypic ratio of the offspring?

Number Phenotype

______:

______:

______:

______:

  1. A non-albino woman who cannot taste PTC has a father who is an albino non - taster. She marries a normally pigmented (homozygous) man who is a taster but who has anormal mother that does not taste PTC.

Father’s genotype: ______

Wife’s genotype: ______

Husband’s genotype: ______

Mother’s genotype (2 possibilities): ______

Complete the Punnett square for the cross.

What are the genotypes of the possible children?

MULTIPLE CHOICE

Answer the following multiple choice questions.

  1. Which statement is not true?

A. genotype determines phenotype
B. phenotype determines genotype
C. a phenotype is the physical appearance of a trait in an organism
D. alleles are different forms of the same gene

  1. What is the best way to determine the phenotype of the feathers on a bird?

A. analyze the bird's DNA (genes)
B. look at the bird's feathers
C. look at the bird's beak
D. examine the bird's droppings

  1. Which choice represents a possible pair of alleles?

A. k & t
B. K & T
C. K & k
D. K & t

  1. Which of the following pairs is not correct?

A. kk = hybrid
B. hybrid = heterozygous
C. heterozygous = Hh
D. homozygous = RR

  1. Which of the following is true of mendelian inheritance?
  1. If a dominant allele is present, the recessive allele won’t be seen.
  2. If a recessive allele is present, the dominant allele won’t be seen.
  3. Both recessive and dominant alleles show if present