Excretion, irritability, and reproduction are characteristics of:
d) All animals and some plants only

Excretion, irritability, and reproduction are important characteristics that are found in living organisms. These characteristics help in the survival and continuation of the species. While all animals possess these traits, some plants also exhibit them to a certain extent.

Excretion:
Excretion is the process by which waste products and harmful substances are removed from the body. Animals have specialized organs such as kidneys, lungs, and skin that help in excretion. They eliminate waste products like urine, carbon dioxide, and sweat. Plants, on the other hand, excrete waste products through their leaves, roots, and stems. They release excess water and waste substances through a process called transpiration.

Irritability:
Irritability refers to the ability of an organism to respond to external stimuli. Animals exhibit various forms of irritability, as they have a well-developed nervous system. They can perceive and respond to changes in their environment, such as light, sound, temperature, and touch. Plants also exhibit irritability, although it is not as evident as in animals. Plants can respond to stimuli such as light and gravity, which are important for their growth and survival.

Reproduction:
Reproduction is the process by which living organisms produce offspring of their own kind. Animals reproduce through sexual or asexual means. Sexual reproduction involves the fusion of male and female gametes, leading to the formation of offspring with genetic variations. Asexual reproduction, on the other hand, involves the production of offspring without the involvement of gametes and results in offspring that are genetically identical to the parent. Plants also reproduce through sexual and asexual means. They can produce flowers, fruits, and seeds for sexual reproduction, as well as use vegetative propagation through methods such as budding and runners for asexual reproduction.

Conclusion:
In conclusion, excretion, irritability, and reproduction are characteristics that are found in all animals and some plants. While animals have well-developed systems to carry out these functions, plants also possess mechanisms to perform them to a certain extent. These characteristics are essential for the survival and continuation of both animal and plant species.