Answer:
Answer is Sinoatrial node, SA.
Explanation:
The sinoatrial node, SA, is known to be a group of cells which are found at the top of the heart.
The electrical signal that is initiated by the sinoatrial node bring about or stimulates the atria and then the ventricle of the heart.
It should be noted that, the sinoatrial node are regarded as the pacemaker cells.
Answer: A. Carbon Dioxide
Explanation: This happens because the coal or oil burning process combines carbon with oxygen in the air to make CO2
Idk bro sorry but I’m only in the 7th grade and don’t take biology
Answer:
The correct answer is eukaryotes engulfed photosynthesizing prokaryotes
Explanation:
The endosymbiotic theory or symbiogenesis is an evolutionary theory that traces the origin of eukaryotic cells from prokaryotic organisms. It explains that some of the organelles (Mitochondria and Chloroplasts) in eukaryotic cells evolved from free-living prokaryotic microbes which were ingested or engulfed. The ingested prokaryotic cells survived within the organism and developed a symbiotic relationship.
According to the theory, chloroplasts was formed when eukaryotes engulfed photosynthesizing prokaryotes and mitochondria was formed when bacteria capable of aerobic respiration were engulfed.
