Answer:
heart blood vessels and blood
Answer:
2 membrane layers cover up the nucleus
Euglena are a unicellular organism. They are classified into the Kingdom Protista. They are then further classified into the Phylum<span> Euglenophyta. All euglena can make their own food by photosynthesis.</span>
Natural selection can cause speciation, which increases the biodiversity of an ecosystem. Several bacterial colonies are placed on a petri dish that contains agar with antibiotics. After 24 hours, ninety percent of the original bacteria die, but the remaining ten percent survive and later reproduce.
