On a recent field trip, you discover a new species of plant. since you are interested in plant reproduction, you rear the plant over several generations to study its life cycle. all of the reproductive cells you collect are haploid; however, those formed by meiosis are able to develop directly into a new plant, while those formed by mitosis are unable to do so. you conclude that the haploid cells formed by mitosis are

Gametes

Explanation:

The given plant has a haploid plant body. Haploid gamete mother cells undergo mitosis and form haploid gametes. The gametes should be fused together to give rise to a diploid zygote. The diploid zygote then undergoes meiosis and gives rise to the haploid plant body.  

The haploid plant body bears haploid gamete mother cells and the process continues. The given plant exhibits zygotic meiosis and forms gametes by mitosis.  

d. the weight of the book

nucleus

would be most reasonable answer tbh