4. Explain the life cycle of a frog with diagram.

The life cycle of a frog, known as metamorphosis, involves distinct stages of development from egg to adult frog. Here's an explanation of the life cycle of a frog along with a diagram:

1. Egg Stage (Embryo):

• The life cycle begins with the female frog laying eggs in water bodies such as ponds, lakes, or streams.
• The eggs are typically laid in clusters or masses, often surrounded by a jelly-like substance to protect them from predators and dehydration.
• Each egg contains a fertilized embryo that undergoes development within the protective egg membrane.
• The duration of the egg stage varies depending on species and environmental conditions but typically lasts several days to weeks.

2. Tadpole Stage (Larva):

• Once the eggs hatch, tadpoles emerge from the eggs as aquatic larvae.
• Tadpoles have a fish-like appearance with a long tail, external gills for breathing underwater, and no limbs.
• They feed on algae, plant matter, and other organic material in the water, growing and developing rapidly.
• During this stage, tadpoles undergo metamorphosis, gradually transforming their body structures and physiology to adapt to terrestrial life.

3. Metamorphosis:

• As tadpoles grow, they undergo metamorphosis, a series of morphological and physiological changes to transition into adult frogs.
• One of the first changes is the development of hind limbs, followed by the emergence of forelimbs.
• The tail starts to shrink and eventually disappears as the tadpole absorbs its tissues.
• The gills are replaced by internal lungs for breathing air, and the digestive system adapts to a carnivorous diet.
• Skin changes occur, including the development of a thicker, more textured skin with glands that help retain moisture on land.

4. Adult Frog Stage:

• Once metamorphosis is complete, the tadpole has transformed into a juvenile frog, resembling a miniature version of the adult frog.
• The juvenile frog continues to grow and develop, maturing into an adult frog over time.
• Adult frogs have fully developed limbs for hopping and swimming, as well as specialized features such as vocal sacs (in males) for producing mating calls, and specialized skin adaptations for respiration, water balance, and defense.
• Adult frogs are capable of reproduction and typically return to water bodies to mate and lay eggs, completing the life cycle.

Diagram of the Life Cycle of a Frog: