Based on the characteristics you describe, this is most likely a type of fungi.
Characteristics of Eukaryotic Cells - Boundless
https://www.boundless.com/biology/textbooks/boundless-biology-textbook/cell-structure-4/eukaryotic-cells-60/characteristics-of-eukaryotic-cells-313-11446/
Like a prokaryotic cell, a eukaryotic cell has a plasma membrane, cytoplasm, and ribosomes. However, unlike prokaryotic cells, eukaryotic cells have: a membrane-bound nucleus. numerous membrane-bound organelles (including the endoplasmic reticulum, Golgi apparatus, chloroplasts, and mitochondria)
Red and yellow bell pepper plant can reproduce with each other - Genetic diversity.
A park has 80 species of trees - species diversity.
There are many breeds of dogs - genetic diversity.
Five different bird species are at a bird feeder - species diversity.
Bottleneck Effect where there is a steady decrease over time
