An immature male gametophyte differs from a mature male gametophyte in that it ?
1. has not yet germinated and its generative cell has not divided into 2 male gamete
2. is a microspore that has not yet divided by mitosis
1
Expert's answer
2014-05-29T01:08:14-0400
Gametophyte is plants’ gamete-producing generation. In flowering plants,the pollen grain is the male gametophyte where sperm cells are produced. Pollen mother cells (2n) are produced in the sporogenous tissue withinthe anther. The two divisions of meiosis transform these cells into tetrad of haploid microspores (n). Following release of microspores from the tetrads, there is an extended interphase period that terminates with a very unequal division of the microspore (microspore mitosis), forming a vegetative cell and a generative cell, both of which are included within the confines of the cell wall of the original microspore. In several plants, such as corn, the generative cell undergoes a mitotic division within the pollen grain, forming two sperm cells. In most pollens, however, the generative cell completes its division during the growth of the pollen tube in the style. At maturity, the male gametophyte consists of three cells, the vegetative cell and the two sperm cells, which lie within the cytoplasm of the vegetative cell Thus, the generative cell of immature male gametophyte is not dividedinto two sperm cells. The correct answer is 1
Comments
We cannot call an undivided microspore a "gametophyte", even an immature one
Shouldn't the answer be 2? According to the explanation.
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