8 - Modern Genetics

Which individuals have the trait that is traced by the pedigree?

• F and J

• C E F H

• A C N and O

• B D E G and H

_________ RNA carries coded messages from the nucleus to the cytoplasm.

• ribonucleic

• Transfer

• messenger

• Ribosome

Genetic disorders are caused by ____

• recessive alleles only

• DNA mutations or changes in chromosomes

• dominant alleles only

• pedigrees

A mutation is harmful to an organism if it ______ .

• changes the DNA of the organism

• changes the phenotype of the organism

• reduces the organism’s chances for survival and reproduction

• makes the organism better able to avoid predators

What is a karyotype?

• a sex-linked genetic disorder

• fluid that surrounds a baby before it is born

• a picture of the chromosomes in a cell

• a picture of a baby before it is born

The pairing of ______ in DNA is the key feature that allows DNA to be copied.

• codons

• chromosomes

• nitrogen bases

• nucleotides

A child is diagnosed with a rare genetic disease. Neither parent has the disease. How might the child have inherited the disorder?

• The disorder is sex linked and inherited only from the father.

• The disorder is recessive and carried by both parents.

• The disorder could occur only as a mutation in the child because neither parent had the disease.

• The disorder is dominant and was carried by a parent.

Down syndrome most often occurs when ____

• blood fails to clot properly

• sickle-shaped cells become stuck in blood vessels

• chromosomes fail to separate properly during meiosis

• a person inherits a recessive allele

Which pairs of individuals in the pedigree have children?

• F G

• C E F H

• A C and N O 

• F J

A section of DNA has the base sequence TACA. The corresponding section of a messenger RNA molecule will have the base sequence _ .

• ATGT

• TACA

• CATA

• AUGU