How big is a human egg compared to those little orange smelt eggs? Also, are fish eggs single cells, or are they more complex than that?
I was always taught that the human egg is as big as the period at the end of this sentence. Much bigger than the sperm, which can be seen through microscope only.
As for your fish egg question, having eaten roe, it looks like only one cell. But I can’t say for sure. Hopefully someone will be along to answer that part of the question.
Anyway, how warm is it today in Florida, Shib?
It’s a little bit chilly, although right now it’s fine, around 60-65 F. Tonight it will get down near freezing in a lot of parts of Florida, but tomorrow should be back up around 70. It’s pretty erratic this time of year. Yesterday was pretty nice although a little windy. How’s Albany?
A smelt egg is much more analogous to a chicken egg than a human egg. It contains not only the seed cell, and the genetic material, but also a sac of nutrient-rich broth to sustain the embryo until it is mature enough to survive on its own. Human eggs are fertilized and grow in a very controlled environment that provides all the needed supplies.
Before fertilization, the yolk part of the fish egg consitutes a single cell. (Actually, there is a germinal disk on the yolk that contains the nucleus and cytoplasm of the cell. The yolk material itself constitutes food supplies for the embryo once it starts growing, but this is contained within the cell membrane and hence is part of the cell).
I remember sitting in a korean restaurant a few years back listening to two senior biology professors argue about whether the entire egg is a cell or just the germinal disk. The upshot, IIRC, was that the word “cell” was not sufficiently defined to answer definitively.
It’s a bit chilly? a bit chilly??!! Damn it, can’t swear at you in GQ. It’s The high today in Albany is 3 degrees, and the windchill is -15.
Thursday it’s supposed to be 50 degrees, though, thankfully.
Boo hoo. This morning I was at -17 BEFORE windchill, -35 with.
As an addendum to the OP, I was once told by someone (jsut a random dude, not a teacher or prof. or anything) that a chicken egg is one cell. Is this true? Or, from what I’m reading, is it more accurate to say it is a cell surronded by a crap load of stuff to give it nutrients and protection after it gets fertilized?
Since the yolk material is contained within the cell membrane, I personally would say it’s part of the cell. But in animals with a large amount of yolk, the yolk does not undergo cleavage.
As in the case of fish eggs, the yolk (including the germinal disk} of a chicken egg is a single cell (before fertilization), but not the whole egg. The egg white and shell are extracellular support structures.
Hey, listen to the Pit thread and us northerners should band together! Not fight each other!
And as for the chicken question, I think your second premise is more accurate.
The diameter of a mature human ovum is about 0.2 mm, which is just barely visible to the human eye. On the other hand, I can easily see those little fish eggs, so I estimate their diameter to be at least 0.5 mm.
The yolk material is surrounded by a membrane, but is it a cell membrane? Is is a bilipid layer membrane with embedded proteins and cholesterols?
Yes. It is surrounded by the cell membrane of the original oocyte. The yolk material is simply stored within the developing oocyte.