Given question is incomplete. Complete question has been attached.
Answer:
C. Excessive potassium has diffused out causing hyperpolarization.
Explanation:
The nerve action potential can be divided into following stages:
- Stimulus is detected by the cell in resting stage.
- Sodium channels in the membrane open from where influx of sodium ions occur which is called depolarization
- After a while, sodium channels close and potassium channels open from where efflux of potassium ions occur which is called repolarization.
- The membrane potential further lowers due to continous efflux of potassium ions which is called hyperpolarization.
- After a while potassium channels close and membrane returns to its resting stage.
In the given figure, stage 4 depicts hyperpolarization because the membrane potential has dropped to the lowest point below -70mV. Hence, option C is correct.
Answer:
low level of calcium would result in fewer signals sent between pre and post synaptic cells.
Explanation:
The calcium has a main role in signal transmission mechanism and here is the mechanism :
1-the impulse reaches the synapse (depolarization which is a voltage change).
2-the voltage gated calcium channels open and let calcium flow into the cell.
3-the calcium causes the synaptic vesicles to rupture and release chemical transmitters which cross the synaptic cleft and finally bind to receptors on the post synaptic cell (transmitting the signal)
so it's obvious that if calcium concentration decreases, the signal transmission also decreases.
D, they need to be able to absorb and keep water to prevent drying out
Answer:Figure: The two stages of photosynthesis: Photosynthesis takes place in two stages: light-dependent reactions and the Calvin cycle (light-independent reactions). Light-dependent reactions, which take place in the thylakoid membrane, use light energy to make ATP and NADPH
Explanation: