Answer:
Bacteria
Explanation:
Leucosomes are the white blood corpuscles or WBCs which is come out to protect the body from bacteria and other infections.
The last one I’m pretty sure, we learned about this last year in science
Answer:
Background extinction
Explanation:
The background extinction refers to the diminishing of the species at a fairly slow and constant rate. This extinction takes place because of the various environmental factors namely the changing climatic conditions, spreading of diseases, and destruction of habitat. It plays an important role in the natural process of evolution. This has been taking place continuously throughout the geological time and the species are undergoing continuous evolution over a specific period of time.
