Since a secondary source is a source written after an event has occurred, I want to say that the answer is A. Hope this helped!<span />
The parts of the heart are the atria, ventricles, septum, valves. The atria collects oxygenated blood that has returned from the lungs.The ventricles , receive blood from the atria. The septum it separates the left atrium and ventricle from the right atrium and ventricle. Finally, the valves<span> separate the various parts of the heart from one another. They allow blood into places it’s supposed to be and keep it out of places it’s not supposed to be.
Undoubtedly, there are more parts of the heart but these are the main functions.
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Answer:
there would be less birds.
Explanation:
If the population decreases the birds are dying. Therefore leaving the planet with less birds.
Bacteria protects the cell in your intestine and helps us absorb fatty acids. It is harmful because when you have contact with it, the bacteria can reproduce in your body, damaging it and making you sick.
Answer:
Chromatin is responsible for gene expression.
Explanation:
Chromatin is responsible for gene expression because chromatin contains DNA that has all information about genes. chromatin controls the gene in order to form encoded products. DNA in chromatin send information to the RNA to produce specific types of proteins that are needed by the organisms for its growth and development so in that way the genes can be expressed in the organism.