Identify each of the following structures as haploid or diploid. a. sporophyte b. spore c. gametophyte d. zygote

Verified step by step guidance

1. Identify the ploidy level of each structure by understanding their role in the life cycle of plants. In plants, there are two alternating phases: the sporophyte phase and the gametophyte phase.
2. Recognize that the sporophyte is the diploid phase of the plant. It arises from the fusion of gametes (sperm and egg) and thus contains two sets of chromosomes, one from each parent.
3. Understand that spores are produced by the sporophyte through meiosis. Since meiosis halves the chromosome number, spores are haploid, containing only one set of chromosomes.
4. Note that the gametophyte arises from the haploid spores and is therefore haploid itself. It produces gametes through mitosis, which do not alter the chromosome number.
5. Acknowledge that the zygote is formed by the fusion of two haploid gametes (sperm and egg), making it diploid as it contains two sets of chromosomes.

Key Concepts

Haploid and Diploid

Haploid cells contain one set of chromosomes (n), while diploid cells have two sets (2n). In the context of plant biology, haploid stages are typically associated with gametes and spores, whereas diploid stages are linked to the sporophyte generation. Understanding these terms is crucial for identifying the ploidy of various structures in the life cycle of plants.

Sporophyte

The sporophyte is the diploid phase in the plant life cycle that produces spores through meiosis. It is the dominant generation in many plants, such as ferns and flowering plants. Recognizing the sporophyte's role is essential for determining its ploidy and understanding its function in reproduction.

Gametophyte

The gametophyte is the haploid phase of the plant life cycle that produces gametes (sperm and eggs) through mitosis. In non-vascular plants like mosses, the gametophyte is the dominant generation, while in vascular plants, it is often reduced and dependent on the sporophyte. Identifying the gametophyte's role helps clarify its haploid nature and its contribution to plant reproduction.