Human Genetics

A child is diagnosed with a rare disease. Neither parent has the disease. How did the child inherit the disorder?

• The disorder is dominant and carried by a parent.
• The disorder is recessive and carried by both parents.
• The disorder is sex-linked and inherited only from the father.
• A mutation in the child occurred.

Tags

NGSS.HS-LS3-2

Two healthy parents have a child with CF. What is the best explanation?

• Not the result of a genetic disorder.
• Both parents carry the recessive gene.
• CF is a chromosomal mutation and not related to parental genotypes.
• CF is caused by a mutation in pair 21.

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

CF and Tay-Sachs are typical of recessive disorders concentrated in ___.

• ethnic groups
• families with single child
• countries with hot climates
• the U.S.

Most genetic disorders are caused by the expression of___.

• recessive alleles
• 2 dominant alleles
• one dominant allele
• sex-linked heredity

Tags

NGSS.HS-LS3-2

Which of the following situations is most usual for a dominant allele that results in severe effects in the offspring?

• both parents have the trait
• the trait occurs by mutation
• only a single offspring has the trait
• none of these

Tags

NGSS.HS-LS3-2

A phenotype that results from a dominant allele must have at least ___ dominant allele(s) present in the parent(s).

• one
• two
• three
• four

Following the detection of PKU in an infant, the treatment used in order to prevent brain damage is ___.

• injection of missing enzymes
• physical therapy
• blood transfusions
• dietary adjustments

A human genetic defect that results in the failure to metabolize the amino acid phenylalanine is ___.

• Turner syndrome
• Down syndrome
• phenylketonuria
• cystic fibrosis

Tags

NGSS.HS-LS3-2

A human disorder caused by a dominant gene is ___.

• Tay-Sachs
• CF
• PKU
• Huntington's

Individuals with Huntington's disease 

• undergo progressive deterioration of the nervous system
• find breathing difficult and suffer lung infections
• must have frewuent blood transfusions
• suffer from aneuploidy