Answer:
B
Explanation:
The fatty acid tails of phospholipids are hydrophobic – meaning they are ‘water-hating’. This is why they are in the middle of the bi-lipid layer of the cell membrane 'hiding' from the 'watery' environment of a cell. This poses a challenge in the diffusion of large and charged molecules across the membrane -such as sodium ions. Such molecules need transmembrane protein channels to help them cross the membrane. These are called integral proteins because they are part and parcel of the cell membrane. The cell membrane, in addition, also has glycolipids and glycoproteins on its surface that are significant in the identification of the cell by other cells.
Answer:
D. A silent variant near the 5' end of the TBX1 gene.
Explanation:
TBX1 gene is wild type human being. It gives instructions for making protein called T-box 1. It plays an important role in tissue formation and organs during embryonic development.
D <span> microscopes hope it helps </span>
Answer:
The valves' main job is to keep the blood moving in one direction – back up towards the heart. When the valve is open, blood freely flows upward towards the heart and when the valves are closed, blood cannot flow back
