Final answer:
Ferns and mosses spend 1/2 of their lifecycle as haploid and 1/2 as diploid. In ferns, the haploid gametophyte and diploid sporophyte are both free-living. Moss life cycles are dominated by the haploid gametophyte, with the sporophyte being less obvious. The correct option is 1) Ferns
Step-by-step explanation:
The two plants that spend 1/2 of their life as haploid and 1/2 of their life as diploid are ferns and mosses. In ferns, both the haploid gametophyte and the diploid sporophyte stages are free-living, and each stage takes up approximately half of the plant's lifecycle.
The diploid sporophyte produces haploid spores by meiosis, which then develop into haploid gametophytes. These gametophytes produce gametes, and the fusion of gametes from two individuals forms a diploid zygote that grows into a new sporophyte.
Mosses exhibit a similar alternation of generations; however, their life cycle is dominated by the haploid gametophyte stage, which is the more apparent and familiar moss structure. The less conspicuous diploid sporophyte grows from the gametophyte and eventually produces haploid spores that will generate new gametophytes. The correct option is 1) Ferns