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Sexual Reproduction in Biology

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"Sexual Reproduction in Biology"
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Pst... wanna know the bona fide truth behind sexual reproduction? You know...the details?

Well, there used to be only two ways to reproduce until cloning became a reality.

Nevertheless, the old ways required a certain amount of effort on the propagator(parents) wanting to do the multiplying.

The oldest form of reproduction was asexual (without sex), meaning an organism grew to the point of maturity and split into half to create separate living things... Ouch.

A different method of doing this would require the organism lose part if itself and grow that piece somewhere else. Ever see the eyes of a potato? Those are baby potatoes staring back at you waiting for the opportunity to hop off the ride... creepy huh?

But you're here to talk about sex...which is not so creepy.

Sexual reproduction starts with the union of two special cells. For most animals and some plants these very different cells are known as the smaller of the two, sperm ,and the larger egg (ova). Each of these cells contain separate and incomplete sets of material, aka, chromosomes which hold genetic building instructions.

When the separate chromosomes of each sperm and ova are bought together a new life is created.

There are quite a few ways to bring sperm and eggs together, but the result is always the same... fertilization. That is, as long as nothing is wrong with either one or both of the parents.

Now, sperm have to travel to the egg, and the way they get there depends greatly on the environment and specific needs of the producer.

Okay, you think you know something about the needs of a producer, but what does the environment have to do with sex?

A lot if you live in a fluid environment. Take fish sperm, they move like a lot of other sperm, but instead of having to swim great distances to their destination the male fish kindly drops them like rain drops over a pile of eggs the female left behind.

Or if you're living in the harsh dry dessert opportunity may only come knocking once in a while so, when a male comes a courtin', a lady is going to bank that sperm for future use like, female tarantulas do. So, some animals can reproduce many times from a one night stand...not a good thing if you're human. I'll explain why soon.

Then, if you can't move like the lone pine tree, you let the warm breeze carry your sperm (pollen-spore carrying cells) over to the seed cones of the female.

At last we have mammals. They have offspring that are dependent for months or even years, so evolution made sure that most mammals would only produce children after they had weaned their young.

And...the longer it takes to wean the young the more complex and difficult the union between the sperm and egg becomes.

Let's look at rabbits. They have a simple sex life. A female rabbit goes into heat (ovulates),chemicals fill the air to let the male know she's ready to reproduce...In goes the sperm...Out come the bunnies...They're weaned in a month...It's time for mom to go into heat again.

Humans are a very different animal. Some human babies drag the weaning business out until preschool, and then they're still helpless for at least another 16 years

So, unlike "Bunnys" women don't have obvious signs that tell the male when the eggs are ready. And if sex occurs before ovulation...human females have a harsh environment awaiting the sperm that's bobby trapped with chemical fortresses that are only penetrable at certain times to prevent attacks on immature eggs.

Women also secretly release their eggs in 28 day cycles, usually sending out one at a time to the great disappointment of thousands of sperm because only one sperm is granted a pass inside the egg.

Plus to add to the punch, all those sperm have to run a marathon through the female reproductive organs to get to the egg... wow.

All that, and I'm not even going to get into the pms that builds psychological barriers to keep males at bay.

It's a surprise we're not extinct.

Yet, isn't it amazing how perfectly all living things are designed to reproduce and survive in accordance with their environment and specific needs. It's like we're all perfect machines.

You know...I believe in evolution, but every time I think of the science behind life, I can't help wondering if intelligent design had a hand in evolution.

More about this author: Sangay Glass

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