There are five steps in a life cycle—product development, market introduction, growth, maturity, and decline/stability.

Only birds, turtles, and crocodilians bear no live young at all.

Most mammals give birth to live young, but a few (the monotremes) lay eggs. Live birth also occurs in some non-mammalian species, such as guppies and hammerhead sharks; thus it is not a distinguishing characteristic of mammals.

Earthworms do not show larval and pupa stage during their development. Amphibians and insects usually show metamorphosis.

Life cycles with three stages Some animals, such as chickens, cockroaches and frogs, have three stages in their life cycles. The three stages are the egg, the young and the adult. The young of some of these animals look different from the adults. During the egg stage, the chick develops inside the egg.

1. Chimpanzees. Researchers determined back in 2005 that chimpanzees share somewhere between 98.6 and 99 percent of our DNA.

Birth, growth, reproduction and death represent the four stages of the life cycle of all animals. Although these stages are common to all animals, they vary significantly among species.

Here we list ten animals that would have the longest lifespans living under ideal circumstances.

• Greenland Shark.
• Bowhead Whale.
• Koi Fish.
• Red Sea Urchin.
• Galapagos Giant Tortoise.
• Longfin Eel.
• African Elephant.
• Macaw. Recognisable by their brightly covered feathers, macaws are members of the parrot family.

The life cycle of dogs includes four stages – puppyhood, adolescence, adulthood and senior years. On an average, it is the smaller breeds of dogs which attain maturity faster and live for longer years. Also, dietary needs of your dog change as it travels from one juncture of its life to another.

Roo must be kidding. The life cycle of our favourite marsupial is one of the most extraordinary in the animal world. For starters, the female kangaroo possesses three vaginas and two uteri. Two of the vaginas pass sperm into the uteri, while the other is used to give birth to the baby, or joey.

World’s 12 Most Unique Animals You Never Know

• Tufted Deer. Tufted Deer is one of the small species of deer with canines,live in Burma or Myanmar and China.
• Thorny Dragon. Thorny Dragon is a small species of Australian lizard,covered entirely with conical spines.
• Aye Aye.
• Maned Wolf.
• Gerenuk.
• Babirusa.
• Fossa.
• Proboscis Monkey.

Mammals, reptiles, amphibians, birds, fish, insects and other invertebrates–they each have their own unique way of reproducing life. There is an amazing variety of life cycles within the animal world. Surprisingly, only about 3% of all animal species give birth to live young as part of their life cycle.