IA Heredity Test School:

Team #

Part I: Multiple Choice

Write the letter of the choice that best completes the statements or answers the question.

1.  What does the notation Tt mean to geneticists?

  1. two dominant alleles c. homozygous alleles
  2. two recessive alleles d. one dominant allele and one recessive allele

2.  What is the probability of producing a tall pea plant from a genetic cross between two hybrid tall pea plants?

a.  One in four c. Three in four

b.  Two in four d. Four in four

3.  If the autosomal cells of a goldfish have 94 chromosomes, then its sex cells would have

a.  27 chromosomes c. 37 chromosomes

b.  47 chromosomes d. 57 chromosomes

4.  What do transfer RNA molecules do during protein synthesis?

  1. copy the coded message from the protein and carry it into the nucleus.
  2. copy the coded message from the DNA and carry it into the nucleus.
  3. carry amino acids and add them to the growing protein.
  4. copy the coded message from the DNA and carry it into the cytoplasm.

5.  A purebred chicken with white feathers is crossed with a purebred chicken that has black feathers. Each of their offspring has both black and white feathers. Why does this happen?

  1. both alleles for feather color were dominant.
  2. both alleles for feather color were recessive.
  3. the alleles for feather color are neither dominant nor recessive.
  4. several alleles work together to determine a trait.

6.  What is a mutation?

  1. any change that is harmful to an organism.
  2. any change in a gene or chromosome.
  3. any change that is helpful to an organism.
  4. any change in the phenotype of a cell.

7.  Which nitrogen base in DNA is not part of RNA?

  1. Adenine c. guanine
  2. Thymine d. uracil

8.  During protein synthesis, mRNA

a.  “reads” each three-letter code if bases. c. copies information from DNA in the nucleus.

b.  releases the completed protein chain. d. carries amino acids to the ribosome.

9.  An organism’s physical appearance is its

a.  Genotype c. Codominance

b.  Phenotype d. Heterozygous

10.  If a homozygous black guinea pig (BB) is crossed with a homozygous white guinea pig (bb), what is the probability that an offspring will have black fur?

  1. 25 percent c. 75 percent
  2. 50 percent d. 100 percent

11.  If you were to mate one of the offspring from the problem above with a guinea pig that was heterozygous black, what is the probability that their offspring would have black fur?

  1. 25 percent c. 75 percent
  2. 50 percent d. 100 percent

12.  In which stage of mitosis does do the chromosomes line up across the center of the cell?

a.  Anaphase c. Metaphase

  1. Prophase d. Telophase

The table below shows the genetic code. To find the amino acid that is coded for by the codon UGG in Messenger RNA, look in the row of the first base in the codon – U. Then move to the box that is specified by the second base in the codon – G. Finally, look down the list of amino acids in the box until you find the one in row “G”, the third base in the codon. You should find that UGG is the codon for tryptophan.

13.  If one section of a strand of DNA has the sequence TATCCGCTA, what is the base sequence on the opposing strand of DNA?

14.  If one section of a strand of DNA has the sequence CGCCTCATG , what is the base sequence on the complimentary strand of mRNA?

15.  From the strand of mRNA in the previous question, what is the order of amino acids assembled according to the sequence? (Use the chart above for the possible amino acids)

16.  If the strand of DNA from question 14 had a mutation giving it the sequence CAGCCTCATG, what will be the new sequence of amino acids assembled? (Use the chart above for the possible amino acids)

17.  If one parent has blood type A and the other has blood type B, is it possible for their child to have blood type O?

18.  A man is homozygous dominant for brown eyes. He marries a woman who is homozygous recessive for blue eyes. What percentage of their children will have brown eyes?

19.  A flower is heterozygous dominant for having white petals. This plant is crossbreed with a plant that carries the same genotype. What percentage of the offspring will be red?

20.  A woman is homozygous dominant for tallness. Her husband is heterozygous dominant for tallness, What percentage of their kids will carry the recessive gene for shortness?

21.  In horses, a black coat (B) is dominant to a brown coat (b) and being a trotter (T) is dominant to being a pacer (t). A black horse that is a pacer is crossed with a brown horse that is a trotter. The offspring is a brown pacer. Give the genotype of all three horses.

22.  The ability to roll the tongue is dominant over the inability to do so in humans. If two heterozygous tongue-rollers have children, what genotypes could their children have?

23.  If a non-tongue-roller has children with a homozygous tongue-roller, what will their children’s genotypes be?

24.  Yeti hair can be black, white, or gray in color. A white-haired yeti and a black-haired yeti have all gray-haired children. What genetic pattern is most likely demonstrated here?

25.  A gray-haired yeti couple have two babies: one white-haired and one black-haired. Does this confirm or deny your answer to the last question?

26.  A gray-haired yeti and her black-haired mate want a white-haired baby. Is this possible?

27.  In humans, short fingers (S) and widow’s peak (W) are dominant over long fingers (s) and continuous hairline (w). A dihybrid is married to a dihybrid. What is the chance that any child will have the same phenotype as the parents?

28.  What is the chance that any child from the parents in the problem above will have the same genotype as the parents?

29.  For the pedigree below, the shaded shapes are people in the family who have a narwhal tusk coming out of their forehead.

You need to determine the genotypes of every individual with a letter next to them.

Use a “t” for recessive, and “T” for dominant. (If there are multiple possibilities, list them all)

30.  For the pedigree below, the shaded shapes are people in the family who have an inherited brain disease.

You need to determine the genotypes of every individual with a letter next to them.

Use a “b” for recessive, and “B” for dominant. (If there are multiple possibilities, list them all)


31.  For the pedigree below, the shaded shapes are people in the family who naturally glow n the dark.

What is the probability that the child labeled “F” would glow in the dark?

32.  In the pedigree below, the shaded shapes are affected family members of a particular disease. Based on the pedigree, could this disease be sex liked?

33.  If the disease from the pedigree above is sex linked what would be the genotypes of all the individuals with a letter next to them? (use a capital or lowercase “R” for the genotype).

34.  What is the gender of the person with the karyotype shown below?

35.  Which of the karyotypes below show a person with Turner’s Syndrome?

A. B.

C.