Introduction:
Sexual reproduction is a process that involves the fusion of gametes from two parents to produce offspring. It is an essential process for the propagation of most eukaryotic organisms, including plants and animals.

Biparental:
Biparental reproduction refers to the process of reproduction that involves the contribution of genetic material from two parents. This type of reproduction is the most common form of sexual reproduction in higher organisms. In biparental reproduction, each parent contributes half of the genetic material necessary for the development of the offspring. This type of reproduction is characterized by the following features:

- The production of two different types of gametes (sperm and egg) by the two parents.
- The fusion of the gametes to form a zygote with a unique combination of genetic material from both parents.
- The development of the offspring through a series of mitotic divisions.

Examples of organisms that reproduce biparentally include humans, dogs, cats, birds, and most other animals.

Uniparental:
Uniparental reproduction refers to the process of reproduction that involves the contribution of genetic material from a single parent. This type of reproduction is less common than biparental reproduction and is mostly observed in some plants and animals. In uniparental reproduction, the offspring is genetically identical to the parent and does not involve the fusion of gametes. This type of reproduction is characterized by the following features:

- The production of a single type of gamete by the parent.
- The development of the offspring through a series of mitotic divisions.

Examples of organisms that reproduce uniparentally include some species of plants (e.g., ferns, mosses) and animals (e.g., some species of reptiles, fish, and insects).

Conclusion:
In conclusion, sexual reproduction can be both biparental and uniparental. While biparental reproduction is the most common form of sexual reproduction in higher organisms, uniparental reproduction is mostly observed in some plants and animals. Both forms of sexual reproduction have their advantages and disadvantages and are essential for the propagation and survival of different species.