Source: Adapted from C. A. Huether et al., Maternal age specific risk rate estimates for Down syndrome among live births in whites and other races from Ohio and Metropolitan Atlanta, 1970-1989, Journal of Medical Genetics 35: 482-90 (1998). Figure 8.20B Maternal age and incidence of Down syndrome
-In some plants such as mosses and ferns, there is a multicellular stage in the life cycle that is haploid and a different stage that is diploid. What can you conclude from this?
A) The haploid cells must undergo twice as much mitosis in order to produce a diploid stage.
B) Haploid cells must undergo mitosis to produce a multicellular haploid stage.
C) Meiosis must happen over and over to produce as many haploid cells for a multicellular haploid plant.
D) Haploid cells must undergo meiosis to form gametes.

Question

Source: Adapted from C. A. Huether et al., Maternal age specific risk rate estimates for Down syndrome among live births in whites and other races from Ohio and Metropolitan Atlanta, 1970-1989, Journal of Medical Genetics 35: 482-90 (1998). Figure 8.20B Maternal age and incidence of Down syndrome
-In some plants such as mosses and ferns, there is a multicellular stage in the life cycle that is haploid and a different stage that is diploid. What can you conclude from this?
A) The haploid cells must undergo twice as much mitosis in order to produce a diploid stage. 
B) Haploid cells must undergo mitosis to produce a multicellular haploid stage. 
C) Meiosis must happen over and over to produce as many haploid cells for a multicellular haploid plant. 
D) Haploid cells must undergo meiosis to form gametes.

Quizplus · Accepted Answer

In plants like mosses and ferns, the haploid stage (gametophyte) can indeed undergo mitosis to produce a multicellular haploid organism. This is a key aspect of their life cycle, where both haploid and diploid stages are multicellular, but they use different processes (mitosis for expanding the haploid stage, and meiosis to transition from diploid to haploid stages).