Myofibrils are the building blocks or contractile unit of each muscle fiber. The tiniest functional unit of skeletal muscle, the sarcomere, is found in the myofibrils and is made up of protein filaments: actin (thin) and myosin (thick).
Your correct answer is D metals!
Answer:
The changes in the sequence of nucleotides present within a promoter is a prime cause of the defected transcriptional regulation, which may eventually result in disease. However, not every modification within the sequence of a promoter influences the regulation of transcription, it relies upon the nature and the location of the genetic defect.
When a mutation results within the sequence of a promoter region it may hamper the usual procedures of gene stimulation by affecting the step by step alignment of the transcription factors at the promoter region. Therefore, as a consequence, a mutation within the sequence of a promoter may result in the enhancement or reduction in the level of mRNA and thus protein.
The best answer is B (semi permeable)
The cell membrane of a red blood cell is semi permeable membrane. This is a type of biological membrane that will allow certain molecules or ions to pass through while barring others.
Red blood cells have very thin membranes that allow oxygen diffuse through quickly. They are also permeable to water and osmosis across the membrane occurs very rapidly. In the body, they are bathed in isotonic plasma in which case water movement into the cell is equal to water movement out of the cell and so the cells remain intact.
Seafloor spreading is a process that occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge. Seafloor spreading helps explain continental drift in the theory of plate tectonics.
