I love this idea!!!! I've got something for y'all:
We, animals, go through a pretty straightforward life cycle. We spend our lives as diploid -- having two copies (one from mom, one from dad) of each chromosome. We start out as a zygote, then we become an adult, and the adult will produce either 4 sperm per single gamete-making cell or 1 egg and 3 mini-cells (not usable for us), through meiosis -- which means the gametes are haploid (aka, only have one copy of each chromosome). Then those come together to form a brand new diploid zygote.
Science jargon!
Plants are freakier. Plants go through a diploid life cycle as well, but it's when they reproduce that everything gets weird.
First of all, many plants are hermaphrodites -- a completely separate gender (most animals are naturally hermaphrodites as well, such as worms (annelidas) and mollusks; that is different from fish who change gender throughout their life cycle, because they will go from male to female, never becoming hermaphrodites). Some plants are male, or female -- but some species have all three genders. Marijuana is a classic example of this -- the males only have male flowers, the females only have female flowers, and the hermaphrodites have both and/or their flowers contain both female and male parts. Weeping willow trees have two genders, either male or female. Lots of perrenial yard flowers are pure hermaphrodites -- their species only has one gender.
Pine cones are very gendered, by the way.
((((Fun fact: 300 million years ago, there were no flowers! That includes any species of grass. There were only mosses, ferns, and cycads, conifers, and certain kinds of pines. Before pine trees and conifers took over, there used to be "tree ferns" -- taller than any tree you'll see today (except giant redwoods)! They lasted longer than any species on Earth ever has; yep, no matter what you look at that's alive, it probably wasn't as successful as tree-ferns! Except moss, lol
))))
But it gets cooler! An adult plant (I'm sticking with flowering plants, but all plants have this life cycle) flowers, and goes through meiosis -- that is, the diploid (two copies of genome) forms a haploid (half the genome) cell through meiosis, similar to animals. BUT THEY DON'T PRODUCE GAMETES YET, unlike animals. Male parts produce microspores, often called pollen.
Pollen is the male offspring of the flowering plant. It is genetically different from its parent, and it is called a gametophyte. It's parent is called a sporophyte, because it produces the gametophyte. This is called an alternation of generation -- that's because plants don't reproduce straight forward the way we do. They create an entirely new generation that does it for them!
What an energy/drama saver!
Female plant parts produce the gametophyte called a macrospore. Just like in animals (like us), meiosis produces 4 pollen cells per one gametophyte-making cell. The plant releases these, to an pollinator or the wind or water if aquatic or marine.
The female megaspore is accompanied by 3 cells that in animals are useless. But in plants, the three cells act as a placenta of sorts, and are genetically distinct just like the megaspore. They will help bring nutrients from the flowering plant to the zygote later.
Pollen lands on a flower or other part where a megaspore, and then the pollen begins to grow a tube, and it begins to create sperm. The sperm will meet the egg of the megaspore, and then fertilization happens and the zygote is created!
So, this means that any seed pod you've ever seen is a grandma, a mom, and a grandchild all nurtured in the same place by the mom and grandma, AND assisted by three aunts.
All plants on land do this.
In moss it gets weirder. You can see that the first generation has green leaves and lasts years and years. But if you look closely, you'll see the second generation, which looks totally different -- no leaves, just a long brown stalk that holds the third generation, which will grow leaves.
Isn't that wild?
