Expert: John Locke - 8/12/2010

Question
I had a test and two questions are still bothering me. 1. leaves of ferns differ from leaves of other plants why? i cant decide if its as simple as the reproduction or because they are seedless it seemed like I was missing an easy answer. 2.The lower surface area to volume of a eukaryotic cell results in what? again, I may be missing something obvious, lower metabolic rate length of time to generate? thanks for any help.

Answer
Thanks for using AllExperts.

1. As you are likely aware, ferns reproduce via sporulation and do not produce seeds or flowers. As part of their evolutionary development, they produced leaves (which are more accurately described as fronds) with a notable difference from the leaves of other plants, and you noted it: the fronds of ferns produce sporangia (spores), whereareas other plants produce pollen in a separate reproductive structure.

2. I have excerpted a bit from Doc Kaiser's Microbiology page (http://student.ccbcmd.edu/%7Egkaiser/goshp.html), which expresses the answer so well that I can't elaborate any further on it:

"Prokaryotic cells are generally much smaller and more simple than eukaryotic. Prokaryotic cells are, in fact, able to be structurally more simple because of their small size. The smaller a cell, the greater is its surface-to-volume ratio (the surface area of a cell compared to its volume). For example, a spherical cell 2 micrometers (µm) in diameter has a surface-to-volume ratio of approximately 3:1, while a spherical cell having a diameter of 20 µm has a surface-to-volume ratio of around 0.3:1.

"A large surface-to-volume ratio, as seen in smaller prokaryotic cells, means that nutrients can easily and rapidly reach any part of the cells interior. However, in the larger eukaryotic cell, the limited surface area when compared to its volume means nutrients cannot rapidly diffuse to all interior parts of the cell. That is why eukaryotic cells require a variety of specialized internal organelles to carry out metabolism, provide energy, and transport chemicals throughout the cell."