From
http://answers.yahoo.com/question/index?qid=20060822112755AA5k9FyI had a lot of editing to do!!!
TurtlesMale: Male turtles always have longer nails than the female turtle.
The reason for this is the males use those long nails to be able to hold on to her during mating.
The male will
try to swim directly in front of the female turtle and flutter the long
nails in her face.
The plasteron (underneath shell) will be concave, or indented in a male turtle.
Male turtle tails are always longer than a female turtles tail.
Male turtles are always smaller than the female
In some turtles the male may keep all or most of his vibrant colors.
Female: Female turtle's plasteron (underneath shell) is straight across unlike the males which is concave.
A female turtle's nails are a lot shorter than the male turtle, this is very noticable.
Female turtles will grow sometimes twice the size of the male and appear darker in color.
A female turtle's tail is always shorter and fatter
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From
http://answers.yahoo.com/question/index?qid=20070521063632AAhPVZSome bits of information are from knowlege.
DogsMale: Most male dogs will wee with its leg up.
As I have noticed, a lot of people say they can tell between a male and a female by its private parts.
In male dogs, the position of scrotum is behind the anus, in between the rare legs.
In 2-3 weeks you would be able to see testicles that are enclosed in
scrotum. That is how you distinguish between male and
female puppy.
Female: Most females will wee with its leg down.
In the female puppy dog, you can see vulva in the middle
portion of back legs.
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CatsMale: Male cats will tend to want to go around you more than females.
Male cats more often have undesirable behaviors like fighting,scratching,spraying.
Males seem to be more affectionate and outgoing.
However, most male cats are more aggressive than females.
Female: Females are more quiet and they are more shy.
They are more well behaved and they do not come near you as much as a male would.
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But all pets are different.
I hope I helped!
I got my answer from Yahoo! Answers and my own knowlege.