21) Which of the following is an autosomal recessive disorder?

A) hemophilia

B) Huntington disease

C) Down syndrome

D) sickle-cell anemia

E) Turner syndrome

22) Which of the following genetic disorders is caused by a dominant allele but does not produce symptoms until the affected individual is well into adulthood?

A) Turner syndrome

B) Down syndrome

C) Huntington disease

D) sickle-cell anemia

E) hemophilia

23) In a pedigree chart, a darkened square demonstrates a:

A) diseased male.

B) diseased female.

C) normal male.

D) normal female.

24) A study of several pedigrees demonstrates that two parents are normal. If some of their children express a trait, then the trait is controlled by a:

A) codominant gene.

B) simple dominant gene.

C) recessive gene.

D) sex-linked gene.

25) A pedigree is a representation of:

A) a genetic family tree.

B) a series of chromosomes arranged in order.

C) the inheritance pattern of recessive disorders.

D) the inheritance pattern of dominant disorders.

E) all the genetic disorders that can be inherited.

26) You are tracking the inheritance of a genetic disorder through a family’s pedigree, and you notice that it shows up in every generation. The disorder is most likely:

A) recessive.

B) dominant.

C) X-linked recessive.

27) If more than one sperm fertilizes an egg, which of the following can result?

A) an autosomal dominant disorder

B) an autosomal recessive disorder

C) aneuploidy

D) polyploidy

28) The human genome has how many pairs of autosomal chromosomes?

A) 46 pairs

B) 44 pairs

C) 23 pairs

D) 22 pairs

E) 24 pairs

29) The state of having more than two sets of chromosomes is called:

A) autosomal.

B) dominant.

C) polyploidy.

D) aneuploidy.

E) nondisjunction.

30) What is one difference between polyploidy and aneuploidy?

A) Polyploidy is extra sets of chromosomes; aneuploidy occurs when there are either more or fewer chromosomes than normally exist in its species full set.

B) Humans can be viable as polyploids but not as aneuploids.

C) Polyploidy is extra sex chromosomes; aneuploidy is extra autosomes.

D) Polyploidy is one extra chromosome; aneuploidy is one missing chromosome.

E) Polyploidy causes diseases and disorders in humans; aneuploidy does not.