are sporophytes haploid
The male gametophyte. 1  is a pollen grain (left). 2  The antheridia have been lost; each pollen produces only two sperm. 3  The male pine cones grow on the ends of pine tree branches in the spring (center) 4  The pollen develop from microspores in microsporangia on male pine cones (longitudinal section, right) The haploid (gametophyte) generation gives birth to the diploid (sporophyte) generation, and that diploid sporophyte generation gives birth to the next haploid gametophyte generation, and so on. All plants go through this life cycle, though the (homologous) stages may look very different across taxa. Start studying Gametophyte/Sporophyte. Learn vocabulary, terms, and more with flashcards, games, and other study tools. The sporophyte produces spores (hence the name) by meiosis, a process also known as reduction division that reduces the number of chromosomes in each spore mother cell by half. The resulting meiospores develop into a gametophyte. Both the spores and the resulting gametophyte are haploid, meaning they only have one set of chromosomes. The mature gametophyte produces male or female gametes (or both) by mitosis. The fusion of male and female gametes produces a diploid zygote which develops into a new sporophyte. Alternation of Generations. All Embryophytes and some algae undergo an Alternation of Generations. Each generation of offspring has a different ploidy than the generation before it. Generations alternate from diploid to haploid to diploid to haploid, etc. sporophyte (2n) --> gametophyte (n) --> sporophyte (2n) --> gametophyte (n) --> sporophyte (2n) etc... In short: 1. a haploid (n) gametophyte generates gametes (n) via mitosis 2. gametes fuse to form a diploid (2n) zygote 3. zygote grows mitotically into the sporophyte (2n) 4. A sporophyte (/ s p ɔː r oʊ ˌ f aɪ t /) is the diploid multicellular stage in the life cycle of a plant or alga. It develops from the zygote produced when a haploid egg cell is fertilized by a haploid sperm and each sporophyte cell therefore has a double set of chromosomes, one set from each parent. All land plants, and most multicellular algae, have life cycles in which a multicellular diploid sporophyte phase alternates with a multicellular haploid gametophyte phase. What Are Sporophytes? All plants and some algae have a life cycle in which they undergo alternation of generations. This process involves a haploid multicellular generation called a gametophyte and a diploid multicellular generation called a sporophyte. Haploid means having only one set of chromosomes in your cells and is usually written as 'n.' Gametophytes make haploid unicellular gametes, or sperm and eggs. When a sperm cell fuses with an egg cell, this is called fertilization. It creates a unicellular diploid zygote. This zygote undergoes many rounds of mitosis to become multicellular. We now have a multicellular diploid organism, or sporophyte. Sporophytes in Plants Most algae have dominant gametophyte generations, but in some species the gametophytes and sporophytes are morphologically similar (isomorphic). An independent sporophyte is the dominant form in all clubmosses, horsetails, ferns, gymnosperms, and angiosperms (flowering plants) that have survived to the present day. Spores are haploid reproductive cells. Remember, a sporophyte is a diploid organism, so in order to produce haploid cells with half the number of chromosomes, meiosis must occur. Meiosis is a type of cell division that cuts the number of chromosomes in a cell in half. In sporophytes, it occurs in structures called sporangia (sporangium is singular). Once spores are produced in a sporangium, they are often released into the air. A single haploid spore will undergo mitosis, or cell division without a reduction in chromosome number, to become a multicellular haploid gametophyte.
No, a sporophyte is a diploid organism, so in order to produce haploid cells with half the number of chromosomes, meiosis must occur.