Answer:
Option D, aortic valve
Explanation:
The location of aortic valve i.e between the aorta and left ventricle, allows it to stop the blood from flowing back into the left ventricle.
The other options are incorrect as -
Pulmonary valve being located between the pulmonary artery and right ventricle, stop the blood from flowing back into the right ventricle.
The tricuspid valve and mitral valve stops the blood from flowing back into the right atria and left atria respectively.
Hence, option D is correct.
The DNA is zipped open by the enzyme DNA helicase, to form two singles strands of DNA for that specific area of the DNA.
Then RNA nucleotides are joined to the sense strand to form a complementary strand of RNA, the RNA is small enough to leave the nucleus by the nuclear pores and go to the ribosomes. This process is called transcription
At room temperature and normal atmospheric pressure, covalent compounds may exist as a solid, a liquid, or a gas, whereas ionic compounds exist only as solids. ionic compounds exist in stable crystalline structures. therefore, they have higher melting and boiling points compared to covalent compounds.
Is there an answer choice of ribosomes? Those are the organelles that make protein that are in the cytoplasm and what makes the Rough ER "rough".
