Although the most frequent forms of Down syndrome are caused by a random error, nondisjunction of chromosome 21, Down syndrome occasionally runs in families. Which of the following is the cause of this form of familial Down syndrome? A) an inversion involving chromosome 21
B) a chromosomal aberration involving chromosome 1
C) too many X chromosomes
D) a translocation between chromosome 21 and a member of the D chromosome group
E) a maternal age effect

Which group is noted for the independence of gametophyte and sporophyte generations from each other? a) ferns b) mosses, hornworts, and liverworts c) charophytes d) angiosperms e) gymnosperms

Which genetic disorders, caused by an extra x chromosome (xxy), is characterized by a lack of testicular development in males, effeminate features, possible mental impairment, and a thin stature?

Which of the following initial observations would more directly lead to this research study? a) ginko biloba is cost effective and also possesses heart-protective, antioxidant, anti-inflammatory properties. b) metformin is an effective treatment of patients with t2d, but shows side effects that complicate the disease state. c) over the past several years, the cost of treating t2d within the united states has increased dramatically. d) many plants contain molecules that improve the health and quality of life of patients with a variety of diseases like t2d. e) t2d affects millions of individuals in the usa and worldwide many of who could benefit from improved therapies.