How do snakes excrete or reproduce?


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Snakes are classified in the group known as reptiles. These are organisms with dry skin that is protected by a scaly covering. They have adapted to life on land and have well-developed lungs.

In terms of reproduction, snakes have internal fertilization as do all reptiles. Males and females join their cloacas together and sperm is placed into the female cloaca. They have eggs that are known as amniotic eggs with various membranes that assist in the development of the embryo and provide a food supply.

While most reptiles lay eggs that develop externally, there are some Squamata (snakes and lizards) that are known as ovoviviparous and the young can be born alive. There is no placenta, however, as in mammals. The reptile that develops is nourished by food stored within the egg along with some nourishment and oxygen provided by the cells in the female oviduct. The oviduct is where the fertilized eggs develop. An example of a snake that is ovoviviparous is the garter snake.

Adaptations for the excretion of wastes in snakes include the lungs, kidneys, and cloaca. Snakes can excrete carbon dioxide from their lungs.

Snakes have kidneys that are paired. They can excrete their liquid wastes as urine which contains ammonia or urea depending on where the reptile lives. If it lives on land, the more toxic ammonia is converted to less toxic uric acid and is excreted with a small amount of water. If the reptile lives in the water, it will excrete ammonia which is directly passed into their watery habitat. They lack a urinary bladder and the wastes are sent from kidneys to the cloaca to be excreted.

Feces from undigested food materials are passed from the intestine into the cloaca and expelled.

The cloaca is a common duct for many purposes in reptiles-reproduction as well as the excretion of wastes.

I have attached a link about snakes with a nice labeled diagram.

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