1. Genetic review The diagram above represents the chromosomes of a person with a genetic disorder caused by nondisjunction, in which the chromosomes fail to separate properly. Which chromosome set displays nondisjunction?

2. An illustration of a person’s chromosomes that can be analyzed for the presence of diseases is called a __________. A __________ occurs when one chromosome from a pair is missing. A __________ occurs when there is an extra, or third, chromosome for one pair. A disorder that occurs when there is an extra 21st chromosome, and that results in varying degrees of mental retardation, is called __________ Syndrome. The genetic make-up of an organism is its _______________whereas its physical characteristics is its ________________.

3. The genotype of individual 1 could be The genotype of individual 2 could be

4. Punnett square Tom is colorblind (sex-linked on the X chromosome) and is married to Barbara, who is normal, is expecting another child. What is the probability that their new baby will be colorblind?

5. A genetic pedigree showing that only males are affected by a certain disorder is evidence of what type of inheritance? In humans, the gene for polydactyly (having extra fingers or toes) is dominant over the gene for the normal number of digits. If parents who are both homozygous dominant for polydactyly have four children, how many of these children would most likely have extra fingers or toes?

6. What trait will most likely be observed in all offspring of the above set of parents? Which of the following scientist is know as the “Father of Genetics”? When red and white snapdragons are crossed their offspring are pink. This is an example of ______________. The term that is used when both alleles contribute to the phenotype (such as in chickens with both black and white feathers).

7. Duchene muscular dystrophy is a genetic disorder. It results from a mutation in the gene that code for a protein necessary for muscle strength. A geneticist prepared a pedigree for a family in which the disorder is present in some members.. According to this information, what type of allele is responsible for Duchene muscular dystrophy? 1.Autosomal recessive allele 2.Autosomal dominant allele 3.Sex-linked recessive 4. Sex-linked dominant