Concept explainers
In an alternation of generations life cycle, spores develop into that produce gametes that fuse to give rise to.
a. haploid gametophytes; diploid sporophytes
b. diploid gametophytes; haploid sporophytes
c. haploid sporophytes; diploid gametophytes
d. diploid sporophytes; haploid gametophytes
Introduction:
Alternation of generations is referred to a phenomenon, which occurs in many organisms, mostly in plants, in which they have two different life forms in a single life cycle. Plant showing alternation of generations can exist in two phases gametophyte and sporophyte.
Answer to Problem 1MC
Correct answer:
In the alteration of generation, the spores develop in haploid gametophyte, which gives rise to gametes that fuse to produce the diploid sporophyte.
Explanation of Solution
Explanation for the correct answer:
Option (a) is given that in the alteration of generations, the spores form haploid gametophytes that give rise to gametes, which fuse to produce diploid sporophytes. In the alteration of generation, the spores develop in haploid gametophyte, the gametophyte is haploid. This gametophyte gives rise to the male and female gamete by the process of mitosis. The fertilization of the male and the female gamete gives rise to diploid sporophyte. This sporophyte can undergo meiotic division, which produces spores. Hence, option (a) is correct.
Explanation for incorrect answers:
Option (b) is given that in the alteration of generations, the spores form diploid gametophytes that give rise to gametes, which fuse to produce haploid sporophytes. The gametophytes are the haploid structures, which fuses to form of the diploid zygote, the zygote later develops into sporophyte, which is diploid. So, it is an incorrect option.
Option (c) is given that in the alteration of generations, the spores form haploid sporophytes; that give rise to gametes, which fuse to produce diploid gametophytes. The spores form the haploid gametophytes and gametophyte result in the formation of gametes. These gametes fuse to form the diploid zygote, which forms diploid sporophyte. So, it is an incorrect option.
Option (d) is given that in the alteration of generations, the spores form diploid sporophytes that give rise to gametes, which fuse to produce haploid gametophytes. The diploid spores form the haploid gametophyte, and the fusion of two gametophyte result in the formation of diploid zygote and lately the zygote forms the diploid spores. So, it is an incorrect option.
Hence, options, (b), (c), and (d) are incorrect.
Thus, it can be concluded that the haploid spores develop in the haploid gametophyte. The gametophyte produces the male and the female gametes by the process of mitosis. The fusion of the male and the female gametes gives rise to the diploid sporophyte, which can undergo the meiotic divisions to form haploid spores.
Want to see more full solutions like this?
Chapter 22 Solutions
Biology: Life on Earth (11th Edition)
- In the life cycle of a bryophyte, represent(s) the gametophyte (haploid) form and represents the sporophyte (diploid) form. A. microscopic gametes; a multicellular leafy structure B. the multicellular foliose form; a smaller, temporary, dependent structure C. a gemmae cup; the leafy permanent portion D. a multicellular foliose form; a gemmae cup E. a multicellular foliose form; a collection of spores or soriarrow_forwardOne of the genera of Lycophytes are the Selaginellaceae. Like other Lycophytes, Selaginellids bear their spores in a strobilus but they have an unusual strobilus. Which answer below best describes this difference? O their spores are always diploid O they are gaemtophyte dominant O their spores are heterosporous O their strobilus is dependnent upon the female gametophyte like mosses APR 25 étv MacBook Pro G Search or type URL @ #3 % %24arrow_forwardLabel the Heterosporous Vascular Plant life cycle: A: Microgametophyte B: Antheridium C: Archegonium D: Zygote E: F: G: H: J: K: Meiosis L: M:arrow_forward
- Give the PLOIDY of the following (ex: haploid, diploid, etc…)1. oospore2. prothallus 3. androcyte4. archegonium5. endosperm6. microsporocyte7. antherozoids 8. oosphere9. megaspore10. protenemaarrow_forwardDraw a simple diagram illustrating a heterosporous life cycle. Include the sporophyte generation, megaspore, female gametophyte, egg, microspore, male gametophyte, sperm, meiosis, and fertilization. Be sure to indicate whether each generation or kind of cell is haploid or diploid.arrow_forwardByrophytes are usually found in areas that are very wet or damp at least part of the year. Which of the following statements describes characteristics of byrophytes that make them dependent on water? State all that numbers that apply. 1. They have a dominant gametophyte phase. 2. They have swimming sperm that need water so they can swim to fertilize the eggs of other nearby plants. 3. They do not have lignin-stiffened vascular tissue or roots to effectively distribute water throughout the plant.arrow_forward
- #6 Match the reproductive structure to the correct generation and type of cell division that produces it in plants. 1.spores (match spores to one of the letters below) A. Made by sporophytes, through meiosis B. Made by gametophytes, through mitosis C. made by gametophytes, through meiosis D. Made by sporophytes, through mitosis 2. gametes (match gametes to one of the letters below) A. Made by sporophytes, through meiosis B. Made by gametophytes, through mitosis C. made by gametophytes, through meiosis D. Made by sporophytes, through mitosisarrow_forwardбуmnosperms Type of spore formed by heterosporous species which give rise to female gametophytes. A. Hetrospores B. Mergasporngiav C. Homospores D. Megasporesarrow_forwardThe photo below is a longitudinal section (I.s.) of the strobilus of Selaginella at 40x. How does this photo illustrate the importance of the previous question?arrow_forward
- Some fungal species can undergo both sexual and asexual life cycles. During very hot seasons fungi prefer; Select one: a. Asexual reproduction by mitosis, to reduce its genetic diversity b. Asexual reproduction by mitosis to reduce the number of spores c. Asexual reproduction by mitosis to produce diploid cells d. Sexual reproduction by meiosis to produce haploid spores that can resist extreme conditions e. Asexual reproduction by mitosis, as this process needs less energyarrow_forwardFungi would best be described as having which of the following life cycles? A. diploid-dominant B. alternation of generations C. gametophyte dominant D. haploid-dominantarrow_forwardOne of the genera of Lycophytes is Selaginella. Like other Lycophytes, Selaginellids bear their spores in a strobilus but they have an unusual strobilus which sets them apart from their relatives. Which answer below best describes this distinction? their spores are always diploid O they are gametophyte-dominant their spores are heterosporous their strobilus is dependnent upon the female gametophyte like mossesarrow_forward
- Biology (MindTap Course List)BiologyISBN:9781337392938Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. BergPublisher:Cengage LearningBiology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStax
- Concepts of BiologyBiologyISBN:9781938168116Author:Samantha Fowler, Rebecca Roush, James WisePublisher:OpenStax College