Which is a birth defect or disorder that occurs as a new case in ...

[asmith134]

Which is a birth defect or disorder that occurs as a new case in a family and is not inherited?
 
  a. Sporadic
  b. Polygenic
  c. Monosomy
  d. Association

Question 2

Which genetic term refers to the transfer of all or part of a chromosome to a different chromosome after chromosome breakage?
 
  a. Trisomy
  b. Monosomy
  c. Translocation
  d. Nondisjunction

[wshriver]

Answer to Question 1

ANS: A
Sporadic describes a birth defect previously unidentified in a family. It is not inherited. Polygenic inheritance involves the inheritance of many genes at separate loci whose combined effects produce a given phenotype. Monosomy is an abnormal number of chromosomes whereby the chromosome is represented by a single copy in a somatic cell. A nonrandom cluster of malformations without a specific cause is an association.

Answer to Question 2

ANS: C
Translocation is the transfer of all or part of a chromosome to a different chromosome after chromosome breakage. It can be balanced, producing no phenotypic effects, or unbalanced, producing severe or lethal effects. Trisomy is an abnormal number of chromosomes caused by the presence of an extra chromosome, which is added to a given chromosome pair and results in a total of 47 chromosomes per cell. Monosomy is an abnormal number of chromosomes whereby the chromosome is represented by a single copy in a somatic cell. Nondisjunction is the failure of homologous chromosomes or chromatids to separate during mitosis or meiosis.