20. Genes that are located on the same chromosome (Points: 4)
tend to be inherited together.
will appear together in the gamete.
are said to be linked.
may be separated during chromosome pairing and crossing over.
fit all of these characteristics.
21. If a child belongs to blood type O, he or she could NOT have been produced by which set of parents? (Points: 4)
type A mother and type B father
type A mother and type O father
type AB mother and type O father
type O mother and type O father
none of these
22. Achondroplasia is an autosomal dominant disorder. If a newly wedded couple finds after genetic screening that they are both heterozygous for alleles responsible for that genetic disorder, what is their chance to have a normal child? (Points: 4)
0 percent
25 percent
50 percent
75 percent
100 percent
23. In an autosomal disorder such as Huntington's, two carrier parents have the probability of passing the gene on to ______ percent of their children. (Points: 4)
50
0
100
25
75
24. If a daughter expresses an X-linked recessive gene, she inherited the trait from (Points: 4)
her mother.
her father.
both parents.
neither parents.
her grandmother.
25. The failure of chromosomes to separate during mitosis or meiosis is called (Points: 4)
genetic displacement.
trisomy.
crossing over.
nondisjunction.
disjunction.
tend to be inherited together.
will appear together in the gamete.
are said to be linked.
may be separated during chromosome pairing and crossing over.
fit all of these characteristics.
21. If a child belongs to blood type O, he or she could NOT have been produced by which set of parents? (Points: 4)
type A mother and type B father
type A mother and type O father
type AB mother and type O father
type O mother and type O father
none of these
22. Achondroplasia is an autosomal dominant disorder. If a newly wedded couple finds after genetic screening that they are both heterozygous for alleles responsible for that genetic disorder, what is their chance to have a normal child? (Points: 4)
0 percent
25 percent
50 percent
75 percent
100 percent
23. In an autosomal disorder such as Huntington's, two carrier parents have the probability of passing the gene on to ______ percent of their children. (Points: 4)
50
0
100
25
75
24. If a daughter expresses an X-linked recessive gene, she inherited the trait from (Points: 4)
her mother.
her father.
both parents.
neither parents.
her grandmother.
25. The failure of chromosomes to separate during mitosis or meiosis is called (Points: 4)
genetic displacement.
trisomy.
crossing over.
nondisjunction.
disjunction.