The embryonic development of living organisms begins with the formation of a zygote (an egg fertilized by a sperm), and ends with the birth or hatching of the
There are no blood vessels in the derivatives of the skin epidermis (since there are only dead cells), in the epithelial tissue (due to the presence of the
A cell has all the properties of a living thing: – metabolism (absorption, transformation and assimilation, excretion); – a high degree of organization of living substances (cell organelles);
Buffering is the ability of a cell to maintain a slightly alkaline reaction of its contents at a constant level. The introduction or formation of an acid or
Lichens are a symbiotic complex of fungus and algae. The vegetative body (thallus, thallus) of lichens consists of fungal hyphae, in most of them upper and lower cortical