Answer:
protozoan, organism, usually single-celled and heterotrophic (using organic carbon as a source of energy), belonging to any of the major lineages of protists and, like most protists, typically microscopic. All protozoans are eukaryotes and therefore possess a “true,” or membrane-bound, nucleus.
Explanation:
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Answer:
Fertilization
Explanation:
When an egg/sperm is created it only has half the needed dna needing the opposite to create a person. That's why sex required two people.
Answer:
The left and right atrium
Explanation:
The heart has four chambers: two atria and two ventricles.
The right atrium receives oxygen-poor blood from the body and pumps it to the right ventricle.
The right ventricle pumps the oxygen-poor blood to the lungs.
The left atrium receives oxygen-rich blood from the lungs and pumps it to the left ventricle.
The left ventricle pumps the oxygen-rich blood to the body.
