Final answer:
Euglenoids and choanoflagellates are examples of organisms that demonstrate both plant and animal characteristics, with euglenoids having plant-like photosynthesis and animal-like heterotrophy, and choanoflagellates having both plant and animal structural features.
Step-by-step explanation:
Two organisms that exhibit features of both plants and animals are euglenoids and choanoflagellates. Euglenoids like Euglena have chloroplasts and can undergo photosynthesis like plants, but when sunlight is unavailable, they can also absorb nutrients from their environment like animals. Choanoflagellates, on the other hand, are close relatives of animals and display similar feeding structures, yet they are sessile and have similarities in life cycle and cellular structure to both animal and plant kingdoms.
Kingdom Animalia consists of multicellular, heterotrophic organisms like humans and insects that consume organic material. Conversely, Kingdom Plantae includes multicellular, autotrophic organisms that typically generate their own food via photosynthesis. Despite these differences, both kingdoms share a common ancestry, evident from structural features of their cells such as the presence of mitochondria, evidence of evolutionary development from common progenitors.