<span>Answer: occurs when the aortic and pulmonary valves backfill with blood</span>
The second heart sound,that is heard in normal hearts, is generated by the closing of the semilunar valves((the aortic valve and pulmonary valve). Before that, the first sound corresponds to the closing of the atrioventricular valves.
hi there
to answer this response it is :Control your blood pressure.
Keep your cholesterol and triglyceride levels under control.
Stay at a healthy weight.
Eat a healthy diet.
Get regular exercise.
Limit alcohol.
Don't smoke.
Manage stress
i hope this helps you out
Have a great after noon
FaithRawlins14
B Gradually develops stiff outer cell wall for protection is the answer
Answer:
D. They block communication between enhancers and non-targeted promoters
Explanation:
Insulator sequences are the group of DNA sequences that protect the protein-coding regions of the DNA from the surrounding regulatory sequences. Some insulator sequences are present between the enhancers and promoters of a gene. These insulator sequences do now allow these enhancers to regulate the expression of genes by sending inappropriate signals.
However, if the insulator sequences are not present between the enhancers and promoters of certain genes but are located somewhere else, enhancers can upregulate the expression of these genes.
A. Lipid bilayer: the phospholipid bilayer is the membrane of a cell. The bilayer contains lipids, membrane proteins, cholesterol, receptors for various molecules, pumps to transport ions and solutes against the concentration gradient, and many other items necessary for a cell to function and work together with other cells.
b. Osmotic pressure: Osmosis is the flow of water across a semipermeable barrier from an area of low solute concentration to high solute concentration. Osmotic pressure is the lowest possible pressure to prevent this water movement.
c. Endoplasmic Reticulum: the Rough ER synthesizes proteins for use outside the cell. The Smooth ER produces lipids and some steroidal hormones.
A. Lipid Bilayer is therefore the correct answer. Osmotic pressure does not involve the various components of the cell membrane, and the ER's produce proteins and hormones. Therefore A is right.
Hope this helps! :) Let me know if you need a clarification.
