OCR Intro to Genetic Disorders

Approximately how many different genes do humans have?

• More than 20,000

• More than 2,000

• More than 200,000

• More than 2 million

What is every gene responsible for making?

• A particular carbohydrate

• A particular polypeptide

• A particular lipid

• A particular nucleic acid

What are polypeptides?

• Carbohydrates used to make hormones and enzymes

• Lipids that are used to make pigments and receptors

• Proteins that are used to make hormones, enzymes, pigments, receptors, and other important molecules in the body

• Nucleic acids that are used to make hormones and pigments

What are genes?

• A type of chromosome

• Sections of DNA with a specific sequence of chemicals

• The same in every human

• Cells that carry genetic information

How many sets of chromosomes do humans inherit, resulting in how many copies of every gene?

• One set of chromosomes, one copy of every gene

• Two sets of chromosomes, one copy of every gene

• Two sets of chromosomes, two copies of every gene

• Three sets of chromosomes, two copies of every gene

What do dominant alleles represent in genetics?

• Recessive characteristics that are easily masked

• Dominant characteristics that can mask recessive alleles

• Recessive alleles that can block dominant characteristics

• Characteristics that have no impact on inheritance

What is a genotype?

• The physical appearance of an organism

• The combination of alleles an organism inherits

• A type of gene that is always dominant

• A specific location on a chromosome

What does the combination of alleles we inherit determine?

• Our genotype

• Our phenotype

• The gene's dominance

• The gene's location on the chromosome

Which genotype represents a heterozygous condition for eye color?

• BB

• Bb

• bb

• None of the above

Which of the following is an example of an autosomal recessive disorder?

• Cystic Fibrosis

• Huntington's disease

• Down syndrome

• Hemophilia