Answer:
B. Shortens
Explanation:
Myofibrils are components of the animal skeletal muscles that are made up of sacromeres. They perform the muscular contraction and relaxation via the sliding filament model.
To produce motion, A cross-bridge forms between actin and the myosin heads triggering shortening of the sacromere. This shortening of the sacromere results in the contraction of the muscle fibers, which the net effect can be seen to be a shortening of the fibers
Answer:
Diffusion
Explanation:
Diffusion is the spontaneous movement of gases, without the use of any energy or effort by the body, between the alveoli and the capillaries in the lungs.
Answer:
Because butterflies with longer tongues were better equipped to eat nectar from inside flowers, and so it was easier for them to eat and grow. So they were better quipped to survive than those with shorter tongues.
Answer:
Yes, if there is a mutation in the operator of the lac operon in a cell such that the lac repressor always stays bound to the operator. If lactose is added to the cell, the lac repressor loses its ability to bind DNA. It clear off the operator, clearing the way for RNA polymerase to transcribe the operon.
Answer:
Electrical stimulation of the cell is depolarization, and electrical relaxation of cells is repolarization.
Explanation:
The electrical activity of the cell depends on the charges distributed on each side of its membrane, which depends on the presence of ions on each side, extracellular sodium and intracellular potassium.
A cell, like the neuron, at rest has a tendency to be negatively charged in its cytoplasm, while the extracellular space has a positive charge.
- Depolarization of a cell occurs by opening the sodium channels, allowing this ion to enter the cell, resulting in a difference in transmembrane potential. It is electrical stimulation of the cell.
- If the potential difference is maintained and reaches the umbral level, it produces an action potential, which in cells such as the neuron produces an electrical stimulus and in the muscle cell a contraction.
- Repolarization means the opening of potassium channels, the exit of this ion to the extracellular space and the return of the cell to rest.
Learn more:
brainly.com/question/4661368
