1. Are the “leafy” (photosynthetic) portions of the moss the sporophyte or gamet
ID: 61438 • Letter: 1
Question
1. Are the “leafy” (photosynthetic) portions of the moss the sporophyte or gametophyte generation?
a) What evidence would you use to support your answer?
2. Gametangia:
a) What type of gamete is produced by an antheridial head?
b) By an archegonial head?
*In each case, give an example.
3. How does the sporophyte generation of the moss acquire nutrients if it is not photosynthetic?
4. What process is used by the fern sporophyte to produce spores and are these spores diploid or haploid?
5. Is the alternation of generations life cycle of the fern “sporophyte dominant” or “gametophyte dominant”? Explain how you came to that conclusion in your answer.
6. What structures do you look for to classify a plant as vascular?
Explanation / Answer
1a. Gametophyte, it is the dominant haploid stage in the moss, it typically contains protonema and gametophore which produces the leafy shoots that involve in photosynthesis. In contrast, sporophytes are parasitic in nature that relies on gametophyte for food and water.
2a. Male gametes (antheridial head) example: (Hypnum cupressiforme)
2b. Female gametes (archegonial head) example: Physcomitrella patens
These two are mostly seen in bryophytes, ferns, cycads and ginkgo
3. Sporophytes are the diploid generation of the moss, it typically attached to the gametophyte (photosynthetic part) and gains the food and water from it. These nutrients and water pass through the transfer cells which are present in the placental layer, which located in between the gametophyte and the sporophyte. Most importantly, the transfer cells increase the surface area for nutrient exchange by means of its convoluted cell walls.
4. Meiosis (reduction division) occurs in diploid sporophyte the resulting spores in the haploid state
5. Sporophytes are dominant since, the fern gametophytes are very small, heart-shaped, reproduce sexually and live for only a short span of time, whereas, the sporophytes are big and reproduce asexually.
6. Xylum (transports the water and minerals) and Phloem (transports nutrients of the food)
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.